[Numpy-discussion] Code samples in docstrings mistaken as doctests

[Anne Archibald]

2008/6/23 Michael Abshoff <michael.abshoff@googlemail.com>:
> Charles R Harris wrote:
>>
>>
>> On Mon, Jun 23, 2008 at 5:58 PM, Michael Abshoff
>> <michael.abshoff@googlemail.com <mailto:michael.abshoff@googlemail.com>>
>> wrote:
>>
>>     Stéfan van der Walt wrote:
>>      > 2008/6/24 Stéfan van der Walt <stefan@sun.ac.za
>>     <mailto:stefan@sun.ac.za>>:
>>      >> It should be fairly easy to execute the example code, just to make
>>      >> sure it runs.  We can always work out a scheme to test its validity
>>      >> later.
>>
>>     Hi,
>>
>>      > Mike Hansen just explained to me that the Sage doctest system
>>     sets the
>>      > random seed before executing each test.  If we address
>>      >
>>      > a) Random variables
>>
>>     we have some small extensions to the doctesting framework that allow us
>>     to mark doctests as "#random" so that the result it not checked. Carl
>>     Witty wrote some code that makes the random number generator in a lot of
>>     the Sage components behave consistently on all supported platforms.
>
> Hi,
>
>>
>> But there is more than one possible random number generator. If you do
>> that you are tied into one kind of generator and one kind of
>> initialization implementation.
>>
>> Chuck
>>
>
> Correct, but so far Carl has hooked into six out of the many random
> number generators in the various components of Sage. This way we can set
> a global seed and also more easily reproduce issues with algorithms
> where randomness plays a role without being forced to be on the same
> platform. There are still doctests in Sage where the randomness comes
> from sources not in randgen (Carl's code), but sooner or later we will
> get around to all of them.

Doesn't this mean you can't change your implementation of random
number generators (for example choosing a different implementation of
generation of normally-distributed random numbers, or replacing the
Mersenne Twister) without causing countless doctests to fail
meaninglessly?

Anne