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Best way to use mathics inside sagemath. Latex issues

asked 2022-05-31 12:23:01 +0100

Nasser gravatar image

updated 2022-05-31 12:36:37 +0100

I just started to learn how to use mathics from sagemath. I am not sure if I am doing it correctly. I just need to use mathics for integration.

Sometimes mathics return result from integration which I need to obtain its Latex. but it seems sagemath command does not know what to do in some cases and return result which does not compile. Here is an example

>sage
┌────────────────────────────────────────────────────────────────────┐
│ SageMath version 9.6, Release Date: 2022-05-15                     │
│ Using Python 3.10.4. Type "help()" for help.                       │
└────────────────────────────────────────────────────────────────────┘
sage: from sage.interfaces.mathics import mathics
sage: res=mathics('Integrate[Sin[x]/(3 + Cos[x])^2,x]')

sage: res
ConditionalExpression[3 + Cos[x], {3 + Cos[x] != 0}]

sage: latex(res)
}0\right\}\right]

Is there a better way to handle such cases? Am I doing something wrong here?

Here is another example

sage: res=mathics('Integrate[x^n*Log[a*x],x]')

sage: res
Piecewise[{{(-1 + n Log[a x] + Log[a x]) x ^ (1 + n) / (1 + 2 n + n ^ 2), n != -1}}, Log[a x] ^ 2 / 2]

sage: latex(res)
}-1\right\}\right\},\frac{\text{Log}\left[a x\right]^2}{2}\right]

Can I add a code to check on result before calling latex on it? This is all done in a script which runs over 10's of thousands of integrals. So need a way to automate this checking in code. Not by looking at output and deciding what to do.

I found the following workaround which I am now using

sage: res=mathics('Integrate[x^n*Log[a*x],x]')
sage: the_latex=mathics('TeXForm['+str(res)+']')

sage: the_latex
\text{Piecewise}\left[\left\{\left\{\frac{\left(-1+n \text{Log}\left[a x\right]+\text{Log}\left[a x\right]\right) x^{1+n}}{1+2 n+n^2},n\text{!=}-1\right\}\right\},\frac{\text{Log}\left[a x\right]^2}{2}\right]

I thought sagemath latex() command will know how to do this directly. Will sage latex() fully support mathics output conversion in the future?

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Comments

First example, Mathics errs :

sage: mathematica.Integrate(sin(x)/(3+cos(x))^2, x).sage()
1/(cos(x) + 3)
sage: integrate(sin(x)/(3+cos(x))^2, x)
1/(cos(x) + 3)
sage: integrate(sin(x)/(3+cos(x))^2, x, algorithm="maxima")
1/(cos(x) + 3)
sage: integrate(sin(x)/(3+cos(x))^2, x, algorithm="sympy")
1/(cos(x) + 3)
sage: integrate(sin(x)/(3+cos(x))^2, x, algorithm="giac")
1/(cos(x) + 3)
sage: integrate(sin(x)/(3+cos(x))^2, x, algorithm="fricas")
1/(cos(x) + 3)
sage: integrate(sin(x)/(3+cos(x))^2, x, algorithm="mathematica_free")
1/(cos(x) + 3)
sage: mathematica.Integrate(sin(x)/(3+cos(x))^2, x).sage()
1/(cos(x) + 3)

but :

sage: mathics.Integrate(sin(x)/(3+cos(x))^2, x)
ConditionalExpression[3 + Cos[x], {3 + Cos[x] != 0}]
Emmanuel Charpentier gravatar imageEmmanuel Charpentier ( 2022-05-31 14:57:34 +0100 )edit

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answered 2022-05-31 15:21:11 +0100

Emmanuel Charpentier gravatar image

You may convert your mathics to a Sage expression and latex that. Using your second example :

sage: latex(mathics.Integrate(x^p*log(a*x), x)._sage_())
\begin{cases}{\frac{{\left(p \log\left(a x\right) + \log\left(a x\right) - 1\right)} x^{p + 1}}{p^{2} + 2 \, p + 1}} & {p \neq \left(-1\right)}\\{\frac{1}{2} \, \log\left(a x\right)^{2}} & {1}\end{cases}

which ask.sagemth.org's Mathjax can't translate...

HTH,

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Comments

Your method worked on the second example but on the first example it gives strange result: Compare sage: var('x p a') sage: latex(mathics.Integrate(sin(x)/(3+cos(x))^2, x)._sage_()) which gives this result \text{\texttt{System ConditionalExpression[System Plus[3,{ }System Cos[Global x]],{ }System List[System Unequal[System Plus[3,{ }System Cos[Global x]],{ }0]]]}} But using TeXForm gives sage: mathics('TeXForm[Integrate[Sin[x]/(3+Cos[x])^2, x]]') gives \text{ConditionalExpression}\left[3+\text{Cos}\left[x\right],\left\{3+\text{Cos}\left[x\right]\text{!=}0\right\}\right] So I think for now, will use TeXForm for everything when using mathics in sagemath as it seems to produce better latex for all examples.

Nasser gravatar imageNasser ( 2022-05-31 23:24:05 +0100 )edit

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Asked: 2022-05-31 12:23:01 +0100

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Last updated: May 31 '22