Opened 11 years ago

Last modified 9 years ago

# random_prime is badly documented. — at Version 5

Reported by: Owned by: drkirkby mvngu major sage-duplicate/invalid/wontfix documentation fwclarke, burcin N/A

### Description (last modified by fwclarke)

The `random_prime()` function in Sage can take one, two or three arguments. But all the examples shown in the documentation or `random_prime` use only one argument. The more complex cases are not documented and not tested.

These are the examples given.

```        sage: random_prime(100000)
88237
sage: random_prime(2)
2
```

Although some with good Python knowledge may argue the behavior with 2 or 3 arguments is documented properly, I personally think it could be clearer.

For example, I'm told:

```random_prime(123,False)
```

would normally be written as

```random_prime(123, proof=False)
```

It would be good with someone with decent Python knowledge to write some examples of using this function with 2 or 3 arguments.

See also #10112, where it is shown that the function hangs for certain erroneous inputs.

It should also be noted that the error message "n must be greater than lbound " is incorrect, and should be changed to "n must be at least lbound"

Fixed by #10112, please close as duplicate.

### comment:1 Changed 11 years ago by drkirkby

• Description modified (diff)

### comment:2 Changed 11 years ago by mhansen

See the patch at #10112.

### comment:3 Changed 10 years ago by drkirkby

• Cc fwclarke burcin added
• Description modified (diff)

Since there appears to be some disagreement about the code changes on #10112, if those can't be resolved soon, I suggest we just change the documentation on this ticket. The 3 changes needed are:

• The error message "n must be greater than lbound " is incorrect, and should be changed to "n must be at least lbound"
• The example `random_prime(200, lbound=100)` is added
• The example `random_prime(200, proof=False, lbound=100)` is added.

### comment:4 Changed 9 years ago by fwclarke

• Status changed from new to needs_review

### comment:5 Changed 9 years ago by fwclarke

• Description modified (diff)
• Status changed from needs_review to positive_review
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