On Tue, Jul 8, 2008 at 1:26 PM, Ondrej Certik <[EMAIL PROTECTED]> wrote:
> On Tue, Jul 8, 2008 at 8:52 AM, William Stein <[EMAIL PROTECTED]> wrote:
>>
>> On Mon, Jul 7, 2008 at 9:12 PM, Elliott Brossard
>> <[EMAIL PROTECTED]> wrote:
>>> Hi William,
>>>
>>> I am becoming more familiar with both Linux and Sage now, which makes things
>>> much easier. I finished porting the Maxima and Wester integration tests to
>>> Sage, though there are many that currently fail...I've attached them, if
>>
>> You attached only the ones that fail? Where are the ones that succeed?
>>
>>> you'd like to see. The problem that many of them have results from ambiguity
>>> of variables under a radical, in a denominator, or in a function with a
>>> restricted domain. As an example, inputting
>>
>> Can you just make a new test that tests each case?
>>
>>> var('a')
>>> integrate(log(x)/a, x, a, a+1)
>>>
>>> will throw an error: 'is a positive or negative?' Two assume
>>> statements--assume(x+a+1>0) and assume(a-1>0)--render Sage capable of
>>> responding, and it outputs
>>>
>>> ((a + 1)*log(a + 1) - a*log(a) - 1)/a
>>>
>>> My TI-89 calculator, which uses Derive, gets the same result, though without
>>> using 'assume' in any form. Trouble is, I can't imagine there's a quick fix
>>> for this, and since most of the failing integrals are from Maxima's own test
>>
>> It would likely be possible -- though difficult (maybe not too difficult) --
>> to have Sage automatically give all possible answers to Maxima and
>> construct a conditional integral expression that gives each possible
>> answer for given conditions.
>
> Also Gary will probably fix this in his symbolics, currently it gives
> me in the sage-symbolics branch:
>
> sage: var("a")
> a
> sage: integrate(log(x)/a, x)
> ---------------------------------------------------------------------------
> NameError Traceback (most recent call last)
>
> /home/gfurnish/sage-3.0.3/<ipython console> in <module>()
>
> NameError: name 'integrate' is not defined
Sorry, I used a wrong sage. It probably works in sage-symbolics, let me try.
O.
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