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Topic: An independent integration test suite
Replies: 42   Last Post: Jul 25, 2013 6:09 PM

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 daly@axiom-developer.org Posts: 100 Registered: 11/9/05
Re: An independent integration test suite
Posted: Jul 16, 2013 4:00 AM

On Tuesday, July 16, 2013 2:19:26 AM UTC-4, Albert Rich wrote:
> On Monday, July 15, 2013 9:36:04 AM UTC-10, da...@axiom-developer.org wrote:
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> > In order to ensure that the answers of the integration differ by no
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> > more than a constant I've been differencing the expected answer from
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> > the Axiom answer and then taking the derivative.
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> >
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> > by non-zero constants. [...]
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> The first sentence above correctly asserts that it is ok for antiderivatives to differ by a constant. Yet, the second sentence finds it surprising that they do differ. So what is the problem?
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> Albert

suppose
t0:= expression
r0:= expected result
a0:= integrate(t0,x)
m0:= a0 - r0
d0:= differentiate(m0,x)

m0 is the difference between Axiom's result and the expected result.
d0 is the derivative of m0, usually with a value of 0.

m0 often shows that Axiom's result and the expected result differ
and the derivative result of 0 shows that this is just a constant.

When I look at the reason for the constant difference it seems to be
related to the trig identities we chose. What system did you use to
create the expected results?