id,summary,reporter,owner,description,type,status,priority,milestone,component,resolution,keywords,cc,work_issues,upstream,reviewer,author,merged,dependencies,stopgaps
3350,plot_vector_field error,mhampton,somebody,"Sometimes functions in plot_vector_field are evaluated on the wrong argument somehow:

Subject: Re: plot directional field differential equations
From: Georg Muntingh <georg.munti...@gmail.com>
To: sage-support <sage-support@googlegroups.com>

You can use the plot_vector_field command:
# Declare your variables:
var('x t')
# Define you function, for instance:
def f(t,x):
    return t*x
There seems to be something awry, however, compare
plot_vector_field((lambda t, x: 1, x), (-1, 1), (-2, 2))
plot_vector_field((lambda t, x: 1, x + 0.001*t), (-1, 1), (-2, 2))
(the second one is what one expects for the differential equation x' =
x)

Why does the vector field look so different when it depends only on one coordinate?",defect,closed,major,sage-duplicate/invalid/wontfix,graphics,invalid,"plot_vector_field, plot",,,,,,,,