Opened 13 years ago
Last modified 9 years ago
#4529 closed enhancement
Implement plots with logarithmic scale — at Version 70
Reported by: | ronanpaixao | Owned by: | ronanpaixao |
---|---|---|---|
Priority: | major | Milestone: | sage-5.2 |
Component: | graphics | Keywords: | plot log scale |
Cc: | Merged in: | ||
Authors: | Punarbasu Purkayastha, Karl-Dieter Crisman | Reviewers: | Karl-Dieter Crisman, Punarbasu Purkayastha |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | #12810, #12605, #12974 | Stopgaps: |
Description (last modified by )
Attached is a patch which introduces log scale to Graphics()
class.
Depends on #12974.
Apply
- trac_4529-add-log-scale.patch
- trac_4529-single-tick.patch
- trac_4529-docs-and-funcs.patch
- trac_4529-more-doc.patch
- trac_4529-typo_fixes-rebase.patch
- trac_4529-final-fixes.patch
Alternate instructions:
Apply the following patches in the specified order. SAGE_ROOT
is the directory where the sage installation is present.
cd SAGE_ROOT/devel/sage ../../sage -hg qimport -P http://trac.sagemath.org/sage_trac/raw-attachment/ticket/12974/trac_12974-fix_graphics_attributes-rebase.patch ../../sage -hg qimport -P http://trac.sagemath.org/sage_trac/raw-attachment/ticket/12974/trac_12974-refactor.patch ../../sage -hg qimport -P http://trac.sagemath.org/sage_trac/raw-attachment/ticket/12974/trac_12974-reorder_some_arguments.patch ../../sage -hg qimport -P http://trac.sagemath.org/sage_trac/raw-attachment/ticket/12974/trac_12974-whitespace-rebased.patch ../../sage -hg qimport -P http://trac.sagemath.org/sage_trac/raw-attachment/ticket/4529/trac_4529-add-log-scale.patch ../../sage -hg qimport -P http://trac.sagemath.org/sage_trac/raw-attachment/ticket/4529/trac_4529-single-tick.patch ../../sage -hg qimport -P http://trac.sagemath.org/sage_trac/raw-attachment/ticket/4529/trac_4529-docs-and-funcs.patch ../../sage -hg qimport -P http://trac.sagemath.org/sage_trac/raw-attachment/ticket/4529/trac_4529-more-doc.patch ../../sage -hg qimport -P http://trac.sagemath.org/sage_trac/raw-attachment/ticket/4529/trac_4529-typo_fixes-rebase.patch ../../sage -hg qimport -P http://trac.sagemath.org/sage_trac/raw-attachment/ticket/4529/trac_4529-final_fixes.patch ../../sage -b
OLD DISCUSSION BELOW :)
Currently plot() has no option to use logarithmic scales.
One workaround is to use matplotlib directly, with its semilogy(), semilogx() and loglog() functions, but that wouldn't produce plots with the customisations implemented in sage. Another workaround is messing with the plot figure like:
import pylab p=plot(x,marker='.') f=pylab.figure() f.gca().set_xscale('log') p.save(figure=f)
But that creates two problems:
- The first problem is that the adaptive choosing of points just considers linear scale, so the points get too much spaced apart in the beginning of the plot and too close in the end.
- The second problem relates to the axis, which, for the same reason, isn't located right.
Also, this requires the user to know how to deal with figures, which is not directly exposed by sage.
There are some possibilities to fix that:
- Make plot() detect if the figure changes the scales and modify the adaptive algorithm and the axis codes accordingly
- Create a kwarg to tell plot() to implement the scale-change internally
- Create other functions to use loglog(), semilogx() and semilogy()
- Many (or all) of the above together, since they aren't mutually exclusive
From what I noticed, Mathematica implements the separate functions way, but it may be better to fix the issue in plot() itself and if the other functions are wanted, just make it so that they call plot() with the correct arguments
Change History (83)
Changed 13 years ago by
comment:1 Changed 13 years ago by
- Milestone changed from sage-wishlist to sage-duplicate/invalid/wontfix
- Resolution set to duplicate
- Status changed from new to closed
comment:2 Changed 13 years ago by
- Resolution duplicate deleted
- Status changed from closed to reopened
comment:3 Changed 13 years ago by
- Owner changed from somebody to ronanpaixao
- Status changed from reopened to new
comment:4 Changed 13 years ago by
- Milestone changed from sage-duplicate/invalid/wontfix to sage-3.2.1
comment:5 Changed 12 years ago by
See #1431 for a way to solve this.
comment:6 Changed 10 years ago by
- Report Upstream set to N/A
comment:7 Changed 10 years ago by
Here are some comments about an API. How about adding a show keyword that specifies the scale of the axes.
scale='log'
-- a string specifies the scale of the vertical axis
scale=('log','linear')
-- a tuple or list of two strings specifies scales for both axes
We'd probably like some way to pass in arguments to the scale, since different scales have different options. This looks ugly: scale=( ('log', {'base': 2}), 'linear')
comment:8 Changed 10 years ago by
We could also do something like xscale='log'
or xscale=('log',{'base': 2})
and similarly for yscale. I don't like using x and y, though, since the variables in the plot might not be x and y.
comment:9 Changed 10 years ago by
My sense is that the API should look like the tick marks API.
Here are some comments Jason made on sage-support about this.
> To change the scale, you can modify the plot afterwards, but I am > running into some sort of problem doing it: > sage: p=plot(e^x,(x,0,10)) > sage: m=p.matplotlib() > sage: from matplotlib.backends.backend_agg import FigureCanvasAgg > sage: m.set_canvas(FigureCanvasAgg(m)) > sage: m.gca().set_yscale('log') > sage: m.savefig('test.png') It seems something was wrong with the plot in the above example, or something. Anyways, starting with: p=plot(x,(x,1,10)) works fine. To do #4529, I'd suggest adding a keyword to show that defines the scales of the x and y axes. I've added some comments to the ticket.
How was I not cc:ed on this ticket before? ;-)
comment:10 Changed 10 years ago by
Also, #5128 would appear to be slightly related.
comment:11 Changed 10 years ago by
The error with e^x
is
MaskError: Cannot convert masked element to a Python int.
but seems to be related to there being something other than linearity involved. Linear functions work, anything with ^
or **
or sin
doesn't.
--> 154 self._renderer.draw_text_image(font.get_image(), int(x), int(y) + 1, angle, gc)
is the problem - it's converting one of the elements, which is supposed to be skipped (masked, right?) to an int.
comment:12 Changed 10 years ago by
logplots.py has a new class LogGraphics
that I implemented and have been using for the past few months. Integrating it with Graphics seemed quite a painful process, so I had to go this direction and make my own class. Currently, it handles many but not all of the arguments that the Graphics
class supports. In addition it uses matplotlib.plt
to do the log plot; otherwise I ran into all sorts of problems with matplotlib (like the ones mentioned in earlier comments).
In engineering, we often need logarithmic plots and the logarithmic plots sometimes is of the form that the x-axis decreases as we go towards the right (for example if we plot decreasing probabilities on the x-axis). This LogGraphics
takes this into account and makes sure that if a list of x-axis points with decreasing values along the higher indices of the list, then it plots the graph with a decreasing x-axis.
comment:13 Changed 10 years ago by
Sorry, I meant matplotlib.pyplot
in the above comment.
comment:14 Changed 10 years ago by
- Status changed from new to needs_review
comment:15 Changed 10 years ago by
I am not sure if this needs to be set to "needs_review". The main thing it is lacking is that it doesn't inherit the Graphics
class, and hence the set of plot options it supports is much less.
On the other hand, I did try to make it inherit the Graphics
class but then I ran into a big hurdle: the variables in the Graphics
class are defined with double underscore __
and so even after I inherit it, I need to use (IMHO ugly) setters and getters in order to access those variables. I tried to overcome this limitation by inheriting Graphics
in the class LogGraphics
and defining a separate (and mostly identical) __init__
in LogGraphics
but then the methods wouldn't work. Since I needed to rewrite almost everything, I decided to just rewrite everything from scratch.
One thing that I plan to do is change all the variables in the Graphics
class to be defined with a single _
and see how it works out. Perhaps then it might be possible to integrate this patch better and consequently have access to all the methods (and hence plot options) available to the plot
command.
comment:16 Changed 10 years ago by
Hmm, that's odd that you had to do this. Here are two "Sage-ic" ideas.
- Have it inherit from
GraphicPrimitive
. That is how most classes are done, and hopefully (?) would work. - Have this be a
show
option, or something like that. In principle, we wouldn't even want the graphic itself to be plotted logarithmically; one could imagine wanting to have aLine
or other plot and then to view it with log, semilog, reverse log, or regular scales. See Jason's wise comment:7.
comment:17 Changed 10 years ago by
GraphicsPrimitive
is unfortunately too crude for most purposes. All the important functions are defined inGraphics
.- I did try using
_render_on_subplot
fromline.py
but ran into the same problem as you described in comment:9. It simply doesn't work since matplotlib fails to re-render the line in log scale. Actually I ran into many more problems; I just can't remember what else. The most painless method seemed to be to use pyplot (or even pylab, but we can avoid importing that since we don't need numpy).
That said, it is IMHO better to have logarithmic plots as a separate class. For instance, it doesn't make much sense to "add" plots with different scalings (and I also raise an error in the class I created).
comment:18 follow-up: ↓ 19 Changed 10 years ago by
- Status changed from needs_review to needs_work
I'm currently cleaning up tickets marked needs_review which have no patches attached, which includes this one, so back to needs_work this goes.
comment:19 in reply to: ↑ 18 Changed 10 years ago by
Replying to kini:
I'm currently cleaning up tickets marked needs_review which have no patches attached, which includes this one, so back to needs_work this goes.
That's fine. I am actually working on a patch which
- modifies the
Graphics
class to have all the attributes start with a single underscore._
instead of.__
. This is already working and passes all doctects at least indevel/sage/sage/plot
- inherits the
Graphics
class and introduces logarithmic plots in a separate file. This is in progress and I hope I have a patch to attach to this ticket soon.
comment:20 Changed 10 years ago by
Awesome. Just yesterday I had a feature request for log-log and semilog plots!
comment:21 Changed 10 years ago by
- Dependencies set to 12974
- Description modified (diff)
I added a patch to Graphics
class which introduces log plots. Some salient points
- I had to "disable" some tick formatting for log plots because matplotlib wasn't behaving well with the formatting that is done in
Graphics().maptplotlib()
(ex. the error in comment:11, out of memory error, etc) - The patch in this ticket relies on the patches in #12974 which is mostly a cleanup of the
Graphics
class. - In trying to implement my own class, I started to look at each of the matplotlib functions more carefully, and found out the reason(s) why setting the scale wasn't working (see point 1.). The result is that I could implement log scale right inside
Graphics
by carefully weeding out the corner cases. I hope I got all the corner cases.
Todo:
- A patch to
plot()
and other functions will take more time to implement. :( - Probably need to make sure that user does not specify tick formatters and locators which don't behave well with log plots.
- Feedback is welcome! I need to know if I missed something.
Example code:
p = plot(exp, 1, 10) p.set_scale('loglog') p.show() xd=range(-5,5); yd=[10**_ for _ in xd]; p=list_plot(zip(xd, yd),plotjoined=True) p.set_yscale('log', 2) # Set only y-axis to log and with base of log being 2. p.show()
comment:22 follow-up: ↓ 23 Changed 10 years ago by
Hmm.. there is still a problem if I modify the Graphics
class. It becomes impossible to add 2D and 3D graphics.
comment:23 in reply to: ↑ 22 Changed 10 years ago by
Replying to ppurka:
Hmm.. there is still a problem if I modify the
Graphics
class. It becomes impossible to add 2D and 3D graphics.
It was a silly thing. I just needed to reorder the check for ._*scale
to after the check for Graphics3d
in __add__()
. The updated patch now passes all doctests in sage/plot
! Also, SHOW_OPTIONS, matplotlib()
have two extra arguments: scale
, base
which are identical in behavior to the arguments in set_scale()
. So, now it is possible to do this:
p = plot(exp, 1, 10) p.show(scale=('loglog', 2))
comment:24 Changed 10 years ago by
- Dependencies changed from 12974 to #12974
comment:25 Changed 10 years ago by
- Description modified (diff)
- Status changed from needs_work to needs_review
Added another patch to other user facing functions. Actually most of the functions in sage.plot.*
work when scale=...
is passed as an argument while calling the function. Using the log scale makes sense in only a couple of them though, and I have added some documentation and examples for the cases I think are pertinent.
Finally, I added some extra functions {loglog,semilogx,semilogy}_plot
, and the corresponding list_plots. I think this should undergo a review now.
These set of patches passes all doctests in devel/sage/sage/plot
.
comment:26 Changed 10 years ago by
- Description modified (diff)
comment:27 Changed 10 years ago by
I hope to be able to go over this very valuable idea at the current Bug Days. Trivial comment while I'm doing a cursory read-through
- ``linear`` -- both the axes are linear.
should probably indicate
- ``'linear'`` -- both the axes are linear.
or
- 'linear' -- both the axes are linear.
and similarly in all other cases, especially when looking at inputs (since it's very important that these are strings, not just commands.
Comments:
- I feel like it would be good to have a little discussion about whether the scale should be "hardcoded" into a Graphics object; somehow this feels not right to me, though I'd hate to ignore the work here for that reason. It just seems better to be able to add plots, then "show" them however we want. Naturally, since a lot of that is set as keywords passed from plot to show, there could be conflicts, but that could be up to the user.
Especially since the bulk of the "work" done in the code still happens in
show
and friends, I don't see why we couldn't just cherry-pick the keywordscale
and handle it like we do things like plot tick formatting, separately fromGraphics
. The interface is cleaner that way.
- Separately, in either case, should we globally import all of these many new functions? For instance, having the
listplot
variants andsemilogx_list_plot, semilogy_list_plot
both available (as opposed tosemilog_plot(keywords=x or y)
) seems overkill.
comment:28 Changed 10 years ago by
- Status changed from needs_review to needs_work
- Work issues set to doctests, strings
It just seemed easier and cleaner to handle the scaling by hardcoding the scale. I will see how the patch turns out if I don't hardcode it.
Most people will expect the functions semilog*
and loglog*
to be present. For instance, matlab has all of those commands (matlab has it only for list plots, the function plotter called ezplot
does not have it AFAIK), and mathematica has LogLogPlot
and LogLinearPlot
.
If it is not desirable, then we can simply have just two functions log_plot(scale='loglog'|'semilogx'|'semilogy', funcs, ...)
, and log_list_plot(scale='loglog'|'semilogx'|'semilogy', data, ...)
.
comment:29 Changed 10 years ago by
+1 to having loglog and semilog convenience functions.
comment:30 Changed 10 years ago by
I think that anything that roughly approximates Mathematica and Matlab is fine, it was just having so many of them that might be a problem. log_plot
and semilog_plot(axis=foo)
or something better would be good, and perhaps a couple similar list_plot
ones... I have to admit I always just use points()
instead of list_plot
, is list_plot
used as the name in one of these programs?
Jason, how many would be useful? It's the semilogx
and semilogy
that seems a bit much, though if it's standard in other programs I guess it would be ok.
comment:31 follow-up: ↓ 32 Changed 10 years ago by
I personally would say a loglog and semilog (defaulting to semilogy) would be good, with an option to switch the semilog to x or y. I guess a list plot would be convenient too, though I agree with you that points() or line() in general should be used over list_plot. They are more powerful (mostly) anyway.
comment:32 in reply to: ↑ 31 ; follow-up: ↓ 33 Changed 10 years ago by
Replying to jason:
I personally would say a loglog and semilog (defaulting to semilogy) would be good, with an option to switch the semilog to x or y. I guess a list plot would be convenient too, though I agree with you that points() or line() in general should be used over list_plot. They are more powerful (mostly) anyway.
For consistency, we should have just one convention. It is very confusing if the options of plot
(except for probably plotjoined
and data
) are also valid options for list_plot
, but then we introduce an inconsistency via log plots. So, I would be in favor of either
- Don't have any of the
loglog_*, semilog*
and handle scaling only through thescale
andbase
parameters ofplot
andlist_plot
(and actually all other plots) - Have all the functions
loglog_plot
,loglog_list_plot
available, and perhaps changesemilog[xy]*
tosemilog*
with an extra optional argumentlog_axis='x'/'y'
. In case we follow this second rule, I would like this extra argument to be different fromaxis
because it can be confused withaxes=True/False
.
I would really like this issue to be sorted out first.
comment:33 in reply to: ↑ 32 Changed 10 years ago by
For consistency, we should have just one convention.
Agreed.
It is very confusing if the options of
plot
(except for probablyplotjoined
anddata
) are also valid options forlist_plot
, but then we introduce an inconsistency via log plots. So, I would be in favor of either
How would this introduce an inconsistency? Is the suggestion on the table that the log option would only be for one of them? I don't see why we can't have our cake and eat it too.
- Log options in
show
orsave
loglog_plot(f,(x,a,b))
is an alias forplot(f,(x,a,b),scale=foo)
- Don't have any of the
loglog_*, semilog*
and handle scaling only through thescale
andbase
parameters ofplot
andlist_plot
(and actually all other plots)
If Mma and friends have it, this is probably not a good idea.
- Have all the functions
loglog_plot
,loglog_list_plot
available, and perhaps changesemilog[xy]*
tosemilog*
with an extra optional argumentlog_axis='x'/'y'
. In case we follow this second rule, I would like this extra argument to be different fromaxis
because it can be confused withaxes=True/False
.
Yes, that's a very good idea!
I would really like this issue to be sorted out first.
Agreed. Jason, should we raise this on sage-devel?
comment:34 follow-up: ↓ 35 Changed 10 years ago by
Sure, let's raise it on sage-devel. Make sure the proposal provides specific options to vote for.
comment:35 in reply to: ↑ 34 Changed 10 years ago by
Replying to jason:
Sure, let's raise it on sage-devel. Make sure the proposal provides specific options to vote for.
Okay, hope I did it clearly enough.
http://groups.google.com/group/sage-devel/browse_thread/thread/af20ea19c09d14a0
comment:36 Changed 10 years ago by
Thanks kcrisman. That poll is comprehensive enough.
Updated the Graphics patch. This now has modifications only to matplotlib and sister functions, and leaves the Graphics
class's attributes alone.
There was a problem with the ticker in that the labels were in scientific notation (ex. 1e10
) and not in the base^exponent
form (ex. 10^10
). This is now fixed, except for the case when the user enters a custom tick formatter. This last case is up to the user to handle.
The interface to plot
and list_plot
remains unchanged. However, I will wait for the poll in sage-devel before deciding what extra plot commands to introduce.
comment:37 Changed 10 years ago by
- Description modified (diff)
- Work issues changed from doctests, strings to convenience functions
comment:38 Changed 10 years ago by
Updated to the correct patch. Apparently I uploaded the wrong patch several hours ago.
comment:39 follow-up: ↓ 40 Changed 10 years ago by
- Description modified (diff)
- Reviewers set to Karl-Dieter Crisman
Some comments:
- Shouldn't
base=2
raise an error whenscale='linear'
in your example? Maybe theif scale is None: return ('linear', 'linear', 10, 10)
could return 'linear', 'linear', None, None? - In
_matplotlib_tick_formatter
, shouldbase
andscale
be next to each other in the function definition? (This is a very minor critique, of course.) - Nice consolidation of the
ticklabels
business at the end of the patch. - Regardless of the outcome of the poll (on which you can vote), I think one should add a lot more examples in the documentation for
show
for the various options. Lots of them. - What's going on with the
pr, i = '', 0
thing removed? I just don't know what it had been doing - seems to have been dead code, but I always get nervous when I have no idea what it used to do... - kini says that the
[13:]
seems brittle if matplotlib's API changes; would it be possible to remove the specific string\\mathdefault
instead? - I wonder about the not setting of the spines outward when the axes shouldn't cross. Here is an example which serves the point:
sage: G = plot(exp(x), (x,5,10)) sage: G.show(scale=('semilogy', 2))
I don't even think this is a very atypical example to arise in practice. It should be documented somehow. - It's fairly easy to have just one tick in a given direction, which usually raises an error in normal plots but isn't raising an error for yours. I'm not sure if one would want to raise an error like "Use a different base so that you get at least two ticks!" or something.
But even with all of these comments, and waiting for the post-poll patch, fantastic job on this. Someone had to come along to finally wrap this for us, it's been requested zillions of times, and this is very worth the effort, thank you so much.
comment:40 in reply to: ↑ 39 ; follow-up: ↓ 42 Changed 10 years ago by
Replying to kcrisman:
Some comments:
- Shouldn't
base=2
raise an error whenscale='linear'
in your example? Maybe theif scale is None: return ('linear', 'linear', 10, 10)could return 'linear', 'linear', None, None?
I had thought about it. My decision was to silently ignore this error because it is not fatal in any way and we handle it properly (i.e. we ignore it and do the right thing).
Edit: This seems to be the same behavior as in matplotlib.
- In
_matplotlib_tick_formatter
, shouldbase
andscale
be next to each other in the function definition? (This is a very minor critique, of course.)
Well, except for subplot
, the rest of the arguments are alphabetically arranged. :) Personally, I find it quite hard to find out where a particular function or argument is present in a typical Sage code. There is no particular manner in which the functions are arranged. Especially in several thousand line files like graphics.py it becomes hard to scroll around and edit code.
- Regardless of the outcome of the poll (on which you can vote), I think one should add a lot more examples in the documentation for
show
for the various options. Lots of them.
I will add some more.
- What's going on with the
pr, i = '', 0
thing removed? I just don't know what it had been doing - seems to have been dead code, but I always get nervous when I have no idea what it used to do...
Yes. I have no idea what it was for. It is dead code, so I removed it.
- kini says that the
[13:]
seems brittle if matplotlib's API changes; would it be possible to remove the specific string\\mathdefault
instead?
To remove it from matplotlib, we need to set rcParams['text.usetex']=True
. But this makes matplotlib try to compile latex on its own and use dvipng to convert from dvi to png, etc. Moreover, this parameter seems to be persistent and remains throughout the current session. So, simply editing the string seemed a more viable option to me.
If the API changes (which seems unlikely to me), then the fix will be very easy too.
- I wonder about the not setting of the spines outward when the axes shouldn't cross. Here is an example which serves the point:
sage: G = plot(exp(x), (x,5,10)) sage: G.show(scale=('semilogy', 2))I don't even think this is a very atypical example to arise in practice. It should be documented somehow.
I will have to see how to handle this. Messing around with the spines was one of the primary reasons why setting scale wasn't working - the "converting masked to int" error.
- It's fairly easy to have just one tick in a given direction, which usually raises an error in normal plots but isn't raising an error for yours. I'm not sure if one would want to raise an error like "Use a different base so that you get at least two ticks!" or something.
I think it is up to the user to either change their range, or their base, or provide custom ticks.
But even with all of these comments, and waiting for the post-poll patch, fantastic job on this. Someone had to come along to finally wrap this for us, it's been requested zillions of times, and this is very worth the effort, thank you so much.
Thanks. I needed it for my own research! :)
comment:41 follow-up: ↓ 43 Changed 10 years ago by
Oh, I didn't mean to prevent \\mathdefault
from coming into the string at all. I meant to just specifically remove the substring \\mathdefault
(say with .replace("\\mathdefault","")
or something).
comment:42 in reply to: ↑ 40 Changed 10 years ago by
I had thought about it. My decision was to silently ignore this error because it is not fatal in any way and we handle it properly (i.e. we ignore it and do the right thing).
Edit: This seems to be the same behavior as in matplotlib.
Okay, just asking. Maybe this should be documented (that is, explained that it's ok that no error is raised).
Well, except for
subplot
, the rest of the arguments are alphabetically arranged. :) Personally, I find it quite hard to find out where a particular function or argument is present in a typical Sage code. There is no particular manner in which the functions are arranged. Especially in several thousand line files like graphics.py it becomes hard to scroll around and edit code.
Oh yeah, it's REALLY hard to find stuff - you just have to get used to it. Ok.
I will add some more.
Great.
Yes. I have no idea what it was for. It is dead code, so I removed it.
Excellent.
If the API changes (which seems unlikely to me), then the fix will be very easy too.
I think kini explained this sufficiently in comment:41. I don't care which way it's done.
- I wonder about the not setting of the spines outward when the axes shouldn't cross. Here is an example which serves the point:
I will have to see how to handle this. Messing around with the spines was one of the primary reasons why setting scale wasn't working - the "converting masked to int" error.
I see. It would be good to have consistency, since we went to some trouble to make them not cross any more.
I think it is up to the user to either change their range, or their base, or provide custom ticks.
Ah! You would think so. But we actually raise an error in the current code in precisely this situation. Presumably the code would be easy to just reuse?
But even with all of these comments, and waiting for the post-poll patch, fantastic job on this. Someone had to come along to finally wrap this for us, it's been requested zillions of times, and this is very worth the effort, thank you so much.
Thanks. I needed it for my own research! :)
Always good to have a good motivator! I've found that using things in class or for some random voting theory thing has ... enhanced my motivation to work on a topic.
Looking forward to seeing the global functions.
comment:43 in reply to: ↑ 41 Changed 10 years ago by
Replying to kini:
Oh, I didn't mean to prevent
\\mathdefault
from coming into the string at all. I meant to just specifically remove the substring\\mathdefault
(say with.replace("\\mathdefault","")
or something).
indeed, the replace seems much better. Thanks.
comment:44 Changed 10 years ago by
- Description modified (diff)
The following are the changes in the latest patches:
- labeling of minor ticks was flaky; it is fixed now.
- added several examples to
show()
- fixed a problem in axes position of the matplotlib() function when custom xmax, xmin, etc were passed. Try this plot (without these patches) and then try with these patches :)
plot(x).show(xmin=1, xmax=-1)
- there is an optional patch where we check for a single tick. this is tricky and I don't know a good and complete solution. Moreover, it makes most of the functions like 'arc, disk, etc' stop "just working" with log scale. It will be good if you have a better idea how to check for ticks which don't affect these functions too. We can't use xmin, xmax, etc to determine ticks because some of them might well be negative and matplotlib will neglect these values.
comment:45 follow-up: ↓ 46 Changed 10 years ago by
Sorry for the delay - I only scheduled a couple hours of work this evening. Tomorrow I will have more time.
Hey, I just had an idea. Maybe this ticket should be only about the ticket description, and then another ticket for adding the "shortcut" commands like plot_loglog
or whatever. In which case the current patches might be enough! (After much testing, of course.) What do you think?
More comments:
- Wow, great catch on all those things like the minor ticks etc. I haven't really tested many of these plots yet, focusing on the code right now, so I'm glad you found a lot of those things.
- We'll eventually want to add some examples (or replace some of these) with the
plot(...,scale='loglog')
format ones. And definitely to add some to the fileplot.py
, since that is where a lot of people will look first for how to get this. But that can wait until the end, I'll be happy to do that in a reviewer patch. - Catching this thing about the flipped
xmin/xmax
and friends is just a bonus - again, great catch and solution. - As to the optional patch, I will think about this some more tomorrow. I do note that things still "work". For the example you removed
G
, the example you removed did in fact work, for instance.sage: G.show(scale=('loglog', 5)) # plots sage: G.show(scale=('loglog', 4)) # plots sage: G.show(scale=('loglog', 6)) # error
because it really depends on the minor ticks as well. I'm not sure whether having minor ticks should count as "having two ticks", especially in the relatively obscure-looking log plot situation. I'm not even sure whysage: G.show(scale=('loglog', 2))
works, since there is only one tick on the left! - So all that said, I really am not sure why this is a problem. If someone is dumb enough to plot a CIRCLE with log scales, then they had better know how to pick the right scale so that this works. But the same would be true for plotting data, as you point out.
- Along those lines, your example (changed)
sage: p = list_plot(range(1, 10), plotjoined=True) sage: p.show(scale='loglog',base=2)
doesn't show any minor ticks. Is that just howLogLocator
works, or is there something wrong?
Obviously at this point we are getting close to nitpicking. I'll try more tomorrow.
comment:46 in reply to: ↑ 45 ; follow-up: ↓ 47 Changed 10 years ago by
Replying to kcrisman:
Sorry for the delay - I only scheduled a couple hours of work this evening. Tomorrow I will have more time.
No problems. It is better to have a good implementation than to hurry through a bad one.
Hey, I just had an idea. Maybe this ticket should be only about the ticket description, and then another ticket for adding the "shortcut" commands like
plot_loglog
or whatever. In which case the current patches might be enough! (After much testing, of course.) What do you think?
Actually, there is zero change to be done to the code in plot
or list_plot
, except to add some examples. The only change that the additional patch will do is make very thin (one-liners) wrappers which defines the plot_*
and list_plot_*
wrappers and pass the correct scale option to plot
and list_plot
. The current consensus from the poll seems to favor this syntax. In view of this, the patch trac_4529-add_docs_eg_to_some_user_facing_functions.patch requires only a renaming of the functions, and some extra examples.
- We'll eventually want to add some examples (or replace some of these) with the
plot(...,scale='loglog')
format ones. And definitely to add some to the fileplot.py
, since that is where a lot of people will look first for how to get this. But that can wait until the end, I'll be happy to do that in a reviewer patch.
We can add exactly similar examples to plot()
and list_plot()
. Currently, since the function is Graphics.show()
, I decided to write it as show(scale=...)
instead of plot(scale=...)
since the former is more pertinent.
- Catching this thing about the flipped
xmin/xmax
and friends is just a bonus - again, great catch and solution.- As to the optional patch, I will think about this some more tomorrow. I do note that things still "work". For the example you removed
G
, the example you removed did in fact work, for instance.
Yes I am aware that the examples I provided work. But most of the examples in the docs of those functions (arc, disk, contour_plot, etc) do not work out of the box, and we get the "too few ticks" error.
I'm not sure whether having minor ticks should count as "having two ticks", especially in the relatively obscure-looking log plot situation. I'm not even sure why
sage: G.show(scale=('loglog', 2))works, since there is only one tick on the left!
Yes. That's why I said that the tick checking function is not robust and I also don't know how to make it robust.
- Along those lines, your example (changed)
sage: p = list_plot(range(1, 10), plotjoined=True) sage: p.show(scale='loglog',base=2)doesn't show any minor ticks. Is that just howLogLocator
works, or is there something wrong?
The minor ticks are generated by passing in multiples of 1/base to the subs parameter of LogLocator?. So, for base 10, you will have ticks at say, 0.1*10^-1, 0.2*10^-1, ..., 0.9*10^-1, 10^-1
. This is a typical way how log plots are drawn in all programs (pyplot.loglog()
, matlab, mathematica, etc). For base=2
you can have only one tick 1/2*2^i
but this is a major tick at 2^(i-1)
. So, you will always see only one major tick and no minor ticks.
Obviously at this point we are getting close to nitpicking. I'll try more tomorrow.
Thanks a lot for the feedback. I am sure I have missed something, so I look forward to it. :)
comment:47 in reply to: ↑ 46 Changed 10 years ago by
Actually, there is zero change to be done to the code in
plot
orlist_plot
, except to add some examples. The only change that the additional patch will do is make very thin (one-liners) wrappers which defines theplot_*
andlist_plot_*
wrappers and pass the correct scale option toplot
andlist_plot
. The current consensus from the poll seems to favor this syntax. In view of this, the patch trac_4529-add_docs_eg_to_some_user_facing_functions.patch requires only a renaming of the functions, and some extra examples.
Oh, I didn't realize that that patch actually already implemented that - I hadn't had time to look at the patches until you had already said which patches to apply! Yes, I should be able to rebase/rename that well for our purposes, just adding a few more examples which occur fairly frequently.
We can add exactly similar examples to
plot()
andlist_plot()
. Currently, since the function isGraphics.show()
, I decided to write it asshow(scale=...)
instead ofplot(scale=...)
since the former is more pertinent.
Of course.
- As to the optional patch, I will think about this some more tomorrow. I do note that things still "work". For the example you removed
G
, the example you removed did in fact work, for instance.Yes I am aware that the examples I provided work. But most of the examples in the docs of those functions (arc, disk, contour_plot, etc) do not work out of the box, and we get the "too few ticks" error.
But they 'work', just not with the log scale, right?
I'm not sure whether having minor ticks should count as "having two ticks", especially in the relatively obscure-looking log plot situation. I'm not even sure why
sage: G.show(scale=('loglog', 2))works, since there is only one tick on the left!
Yes. That's why I said that the tick checking function is not robust and I also don't know how to make it robust.
Haha. Well, I spent about a half-hour looking in depth at the code for matplotlib.ticker.LogLocator
and have decided it is nearly impossible. There will very often, especially for base=2
and friends, be ticks in the locator which are outside of the viewing range.
So there are ways to get some of this information... yuck. I may have something for this later today. I've been looking at it for over an hour and, at least for plots with only positive data, I think I have something. For ones with negative data it would be much more ugly and maybe not worth it.
By the way, I get
sage: sage: disk((0,0), 1, (0, 3*pi/2)).show(scale='semilogx',base=2) /Users/.../sage-5.1.beta0/local/lib/python2.7/site-packages/matplotlib/axes.py:1114: UserWarning: aspect is not supported for Axes with xscale=log, yscale=linear % (xscale, yscale))
when I try something that has an aspect ratio defined (disk, etc.)
The minor ticks are generated by passing in multiples of 1/base to the subs parameter of LogLocator?. So, for base 10, you will have ticks at say,
0.1*10^-1, 0.2*10^-1, ..., 0.9*10^-1, 10^-1
. This is a typical way how log plots are drawn in all programs (pyplot.loglog()
, matlab, mathematica, etc). Forbase=2
you can have only one tick1/2*2^i
but this is a major tick at2^(i-1)
. So, you will always see only one major tick and no minor ticks.
I understood that, but didn't think through the implications for base=2
. By the way, maybe changing
srange(base_inv, 1+base_inv, base_inv)
to
srange(2*base_inv, 1, base_inv)
would be useful, so that minor and major ticks don't overlap... probably doesn't matter, but could be ok.
comment:48 Changed 10 years ago by
So I've come up with a solution. I'll probably post stuff in a little while. Here's a typical example.
sage: P = plot(x^2,(x,1,8),scale='loglog'); P ValueError: Either expand the range of the independent variable to allow two different integer powers of your `base`, or change your `base` to a smaller number. sage: P.show(xmax=10)
Some more food for thought.
- Your LaTeX hack doesn't work in all cases, apparently.
sage: P = plot(x^2,(x,1,8),scale='loglog', base=1.5); P
This is because matplotlib haselse: if usetex: s = r'$%s%d^{%d}$'% (sign_string, b, nearest_long(fx)) else: s = r'$\mathdefault{%s%d^{%d}}$'% (sign_string, b, nearest_long(fx))
which uses decimal formatting, but of course that only makes sense for integer bases. I feel like this is a bug in mpl; what do you think? Anyway, I am hesitant to patch our matplotlib just for this use case, though it should be a new ticket, I think. The same thing happens withbase=3/2
, unsurprisingly. - This also bites your example with
base=float(e)
- did you look at the picture? Plain oldbase=e
should be possible, but hacking around the fact that matplotlib won't accept this maybe makes it not worth it, and in any case I don't know that "real-life" people often use that for semilog plots. Just pointing it out. - Here is a fun horrible example that you probably were thinking of with adding plots - maybe we should find a check for this.
sage: G = plot_vector_field((e^x,e^(x+y)),(x,0.1,10),(y,0.1,10),scale=('loglog', 2)) sage: H = plot(x^2,(x,0,10),scale='linear') sage: G+H
At least originally you thought this should raise an error.
comment:49 Changed 10 years ago by
Almost done with my changes! Here are things that definitely have to be decided or fixed.
- What to do with noninteger bases. Tell people not to use them? Throw an exception? Hack mpl? Give copious examples of them looking bad?
- Decide what to do with adding plots.
Other points.
- I can't get
list_plot
to work withscale='loglog'
or'semilogx'
when passing it a list. From your examples -sage: yl = [2**k for k in range(10)] sage: list_plot(yl, scale='semilogy') # fine sage: list_plot(yl, scale='loglog') # horiz. axis weird, no points sage: list_plot_loglog(yl, base=2) # same weird
I assume this is because there is automatically a change to the list of tuples zipped withrange(n)
, so that there is always a zero involved in the horizontal axis. Here is the real problem.point([(0,1),(1,2),(2,3),(3,4),(4,5)],scale='semilogx',base=2) # doesn't work
What do you think the "correct" behavior is here?
I fixed a bunch of minor doc issues. I also added a lot of
::
between doctests which were meant to be viewed, because otherwise one will not be able to evaluate these plots in the live documentation (this is standard).
Changed 10 years ago by
Changed 10 years ago by
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comment:50 Changed 10 years ago by
- Description modified (diff)
Okay, ppurka, ready for your comments on this whole mess. I've uploaded refreshed patches of yours, as well as a new one of doc fixes. The three issues (non-integer base, adding, list plots with list input) remain, so I am not putting "needs review" yet.
Patchbot: Apply trac_4529-add-log-scale.patch, trac_4529-single-tick.patch, trac_4529-docs-and-funcs.patch, and trac_4529-more-doc.patch.
comment:51 Changed 10 years ago by
- trac_4529-add-log-scale.patch looks good.
- trac_4529-single-tick.patch also seems ok. I guess, we just have to leave it up to the common sense of the user in certain cases.
- trac_4529-docs-and-funcs.patch - I see that you fixed some of the typos!
- trac_4529-more-doc.patch - yes, this is good.
- Adding another patch which fixes some more typos.
list_plot
does seem to behave a bit weird sometimes. But if we useplotjoined=True
, then it works fine. Thanks for figuring out where it goes awry. I will have a look into it. Should the fix go into a separate ticket?- The plot commands in the documentation of
arc
and other functions don't usually work with the check for ticks and with log scale. This is even withbase=2
. For instance, the plot below. I guess we have to leave this up to the user to give a proper input.arc((2,3), 2, 1, angle=pi/5, sector=(0,pi/2)).show(scale='loglog', base=2) arc((2,3), 2, 1, sector=(0,pi/2)).show(scale='loglog', base=2)
- For some commands like
disk
where an aspect ratio warning is given by matplotlib, we can leave it up to the user I think. The fix is relatively simple though; see the code forparametric_plot
in the trac_4529-docs-and-funcs.patch. If we fixdisk
, then we need to weed out all the cases for the rest of the commands insage.plot.*
. - For adding plots - again we leave it up to the user. At present, adding log + linear works and matplotlib handles it. So, we should leave it at that. In my earlier code, I raised error because it was getting ambiguous what scale to set the
Graphics._xscale
, etc attribute to in case the user set the axis to log scale. It seems matplotlib prefers log over linear and sets everything to log.
comment:52 Changed 10 years ago by
- Description modified (diff)
- Reviewers changed from Karl-Dieter Crisman to Karl-Dieter Crisman, Punarbasu Purkayastha
- Status changed from needs_work to needs_review
Added the typo fixes. I am good with your changes. So, it requires your review (as if you haven't reviewed enough already!) ;)
comment:53 follow-up: ↓ 55 Changed 10 years ago by
Forgot about noninteger bases: I think we should discourage the users from using them.
comment:54 Changed 10 years ago by
- Status changed from needs_review to needs_work
- Work issues changed from convenience functions to add warnings to list_plot and non-integer bases
comment:55 in reply to: ↑ 53 Changed 10 years ago by
Thanks for the latest work!
In your latest patch, I see things like
The `"semilogx"` scale
But this will typeset as a LaTeX style thing, which is wrong. Try
The ``"semilogx"`` scale
and then all should be well with those. Easy enough to update on the last patch.
Forgot about noninteger bases: I think we should discourage the users from using them.
Hmm, ok. In that case maybe you can update your latest patch to still do the "e" example but make it really clear that this is (currently) not intended input? I don't want to actually check for integers, though; presumably in some contexts one could want 1.5. Do you think I should report this upstream to mpl?
list_plot does seem to behave a bit weird sometimes. But if we use plotjoined=True, then it works fine. Thanks for figuring out where it goes awry. I will have a look into it. Should the fix go into a separate ticket?
As long as we document that things can screw up on the x-axis for list_plot if you don't use plotjoined=True. That can go in your patch update too :)
If we fix disk, then we need to weed out all the cases for the rest of the commands in sage.plot.*
True. And I noticed the parametric business later on, good catch. I think this might be worth doing. Again, I'm not really worried - we had some fun laughing at the plots one gets from loglog plots of arcs and circles here. But anyway.
It seems matplotlib prefers log over linear and sets everything to log.
Oh, that explains what I saw. I have to say it was very weird.
I await the latest version of the last (?) patch.
comment:56 Changed 10 years ago by
Yes. Working on a lost patch. It should be up in a short while.
comment:57 follow-up: ↓ 59 Changed 10 years ago by
- Status changed from needs_work to needs_review
- Work issues add warnings to list_plot and non-integer bases deleted
I found my "lost" patch. *phew*
comment:58 Changed 10 years ago by
Reporting it to mpl is probably the right way to handle noninteger bases. They can check on their end, and change the labeling to %.2f^{%d}
if a noninteger base is detected.
comment:59 in reply to: ↑ 57 Changed 10 years ago by
I found my "lost" patch. *phew*
Good thing!
I've opened https://github.com/matplotlib/matplotlib/issues/909 for the mpl issue. Hopefully we'll hear something eventually.
Very minor request - on an update of your patch, perhaps.
Note: - Although it is possible to provide a noninteger ``base``, the
maybe that could be in a standard
.. note Although it is possible ...
which would render nicely in the built documentation.
The
.. warning::
should have a blank line after it.
Here's the complete list from sage -docbuild reference html
.
/Users/.../sage-5.1.beta0/local/lib/python2.7/site-packages/sage/plot/graphics.py:docstring of sage.plot.graphics.Graphics.axes_color:3: WARNING: Bullet list ends without a blank line; unexpected unindent. /Users/.../sage-5.1.beta0/local/lib/python2.7/site-packages/sage/plot/graphics.py:docstring of sage.plot.graphics.Graphics.axes_color:5: ERROR: Unexpected indentation. /Users/.../sage-5.1.beta0/local/lib/python2.7/site-packages/sage/plot/plot.py:docstring of sage.plot.plot:89: WARNING: Explicit markup ends without a blank line; unexpected unindent. /Users/.../sage-5.1.beta0/local/lib/python2.7/site-packages/sage/plot/plot.py:docstring of sage.plot.plot:36: WARNING: Explicit markup ends without a blank line; unexpected unindent. /Users/.../sage-5.1.beta0/local/lib/python2.7/site-packages/sage/plot/plot.py:docstring of sage.plot.plot:65: WARNING: Bullet list ends without a blank line; unexpected unindent. /Users/.../sage-5.1.beta0/local/lib/python2.7/site-packages/sage/plot/plot.py:docstring of sage.plot.plot:67: ERROR: Unexpected indentation.
Unfortunately it's too late now for me to properly test everything again - time for bed - but I am not really too concerned, given the stuff I've been trying all along. If you are able to deal with these formatting issues, I'd be grateful, and even if I have to deal with it slowly we should certainly be ready for positive review by the end of the week. Hopefully by tomorrow!
Changed 10 years ago by
comment:60 Changed 10 years ago by
updated the last patch. It should fix the rest of the warnings.
.../sage-5.1beta0/devel/sage» ../../sage -b && ../../sage -docbuild reference html ---------------------------------------------------------- sage: Building and installing modified Sage library files. Installing c_lib scons: `install' is up to date. Updating Cython code.... setup.py:650: UserWarning: could not find dependency <vector> included in /home/punarbasu/Installations/sage-5.1beta0/local/lib/python/site-packages/Cython/Includes/libcpp/vector.pxd. I will assume it is a system C/C++ header. warnings.warn(msg+' I will assume it is a system C/C++ header.') setup.py:650: UserWarning: could not find dependency <string> included in /home/punarbasu/Installations/sage-5.1beta0/local/lib/python/site-packages/Cython/Includes/libcpp/string.pxd. I will assume it is a system C/C++ header. warnings.warn(msg+' I will assume it is a system C/C++ header.') Executing 0 commands (using 0 threads) Time to execute 0 commands: 0.0459749698639 seconds Finished compiling Cython code (time = 0.499665021896 seconds) running install running build running build_py copying sage/plot/plot.py -> build/lib.linux-x86_64-2.7/sage/plot running build_ext warning: Replacing library search directory in linker command: "/home/punarbasu/Installations/sage-5.0.rc0/local/lib" -> "/home/punarbasu/Installations/sage-5.1beta0/local/lib" Executing 0 commands (using 0 threads) Time to execute 0 commands: 0.00115895271301 seconds Total time spent compiling C/C++ extensions: 0.0369729995728 seconds. running install_lib copying build/lib.linux-x86_64-2.7/sage/plot/plot.py -> /home/punarbasu/Installations/sage-5.1beta0/local/lib/python2.7/site-packages/sage/plot byte-compiling /home/punarbasu/Installations/sage-5.1beta0/local/lib/python2.7/site-packages/sage/plot/plot.py to plot.pyc running install_egg_info Removing /home/punarbasu/Installations/sage-5.1beta0/local/lib/python2.7/site-packages/sage-0.0.0-py2.7.egg-info Writing /home/punarbasu/Installations/sage-5.1beta0/local/lib/python2.7/site-packages/sage-0.0.0-py2.7.egg-info real 0m1.513s user 0m1.202s sys 0m0.206s sphinx-build -b html -d /home/punarbasu/Installations/sage-5.1beta0/devel/sage/doc/output/doctrees/en/reference /home/punarbasu/Installations/sage-5.1beta0/devel/sage/doc/en/reference /home/punarbasu/Installations/sage-5.1beta0/devel/sage/doc/output/html/en/reference Running Sphinx v1.1.2 loading pickled environment... done loading intersphinx inventory from /home/punarbasu/Installations/sage-5.1beta0/devel/sage/doc/common/python.inv... building [html]: targets for 1 source files that are out of date updating environment: 0 added, 1 changed, 0 removed reading sources... [100%] sage/plot/plot looking for now-outdated files... none found pickling environment... done checking consistency... done preparing documents... done WARNING: dvipng command 'dvipng' cannot be run (needed for math display), check the pngmath_dvipng setting writing output... [100%] sage/plot/plot writing additional files... genindex py-modindex search copying static files... done dumping search index... done dumping object inventory... done build succeeded, 1 warning. Build finished. The built documents can be found in /home/punarbasu/Installations/sage-5.1beta0/devel/sage/doc/output/html/en/reference
Changed 10 years ago by
comment:61 Changed 10 years ago by
- Description modified (diff)
comment:62 Changed 10 years ago by
Okay, this morning I had time to make one final formatting change and add a few more tests, and change some that would not have looked right. In particular I put the whole warning thing into one warning block - cosmetic, but useful.
I think there are probably a few more corner case things we haven't thought of, but the functionality is now robust enough and well-documented enough in the corner cases we did discover that it's ready for positive review. Although some disagree with this philosophy, my opinion is that for a project like Sage it is better to add new functionality that is 99% ready and then provide quick fixes to minor issues that remain; we simply don't have the resources to spend days trying to break it. If you're happy with it, I'm happy with it. What do you think?
comment:63 Changed 10 years ago by
I am happy with the changes. :)
NB: The patchbot won't work, because it needs to apply the dependency ticket first.
comment:64 Changed 10 years ago by
The patchbot will work - I will make it work!
Patchbot, listen carefully! apply trac_4529-add-log-scale.patch trac_4529-single-tick.patch trac_4529-docs-and-funcs.patch trac_4529-more-doc.patch trac_4529-typo_fixes.patch trac_4529-final-fixes.patch !!!
comment:65 follow-up: ↓ 66 Changed 10 years ago by
I was hoping you'd say: "Patch bot, these are the files you are looking for" (I hope that space makes this comment really just a comment!) (and, uh, that was a star wars reference...)
comment:66 in reply to: ↑ 65 Changed 10 years ago by
Replying to jason:
I was hoping you'd say: "Patch bot, these are the files you are looking for" (I hope that space makes this comment really just a comment!) (and, uh, that was a star wars reference...)
Ha ha! The bot listens only to kini!
comment:67 Changed 10 years ago by
You don't actually have to address the patchbot to make it understand - you just need the word "apply" followed by the correct patch names in the correct order in plain text, possibly on the same line, I don't remember. I just mention the patchbot so people don't wonder what the cryptic comment with patch filenames in it is about.
Changed 10 years ago by
comment:68 Changed 10 years ago by
- Dependencies changed from #12974 to #12810, #12605, #12974
- Description modified (diff)
- Status changed from needs_review to positive_review
Luckily I only had to rebase one of these, due to some fuzz which the release manager doesn't always like. Otherwise this is good to go! Note the long list of dependencies, only so that all patches apply properly on 5.1.beta1.
Positive review!
Patchbot, apply apply trac_4529-add-log-scale.patch trac_4529-single-tick.patch trac_4529-docs-and-funcs.patch trac_4529-more-doc.patch trac_4529-typo_fixes-rebase.patch trac_4529-final-fixes.patch
comment:69 Changed 10 years ago by
- Description modified (diff)
comment:70 Changed 10 years ago by
- Description modified (diff)
"Wrong" sage plot with log scale