sympy
Cannot multiply integral by constant
It seems that when I multiply an integral by a constant, it only calculates the integral part and ignores the constant. If I put the constant in the integral, it works fine.
It shows the the proper calculation at the top of the first ("SymPy") box, but the formatted version below does not show the constant. The answer it shows in the "Antiderivative forms" section does not account for the constant and the full answer is not shown anywhere.
SymPy Live does not seem to have this issue.
works: http://www.sympygamma.com/input/?i=integral%281%2F2*x%29
doesn't work: http://www.sympygamma.com/input/?i=1%2F2*integral%28x%29
@debugger22 are you sure? This is still broken:
That should be \frac12 * \int x dx not just \int x dx.
Sorry I was wrong.
But it's interesting that it works in case of post multiplication. http://www.sympygamma.com/input/?i=integral%28x%29*1%2F2
@nicodjimenez https://github.com/sympy/sympy_gamma/pull/60 contains a fix, you should take a look. I think it wasn't merged because I was testing something related to deployment, but it's been a rather long time.
Thanks @lidavidm. However I am still seeing that expressions are not being parsed correctly, for example: http://60.sympy-gamma-li.appspot.com/input/?i=integrate%28x%29+%2B+integrate%28x%29
Sympy seems to know the answer is x**2 but why doesn't this show up in the SymPy box on top?
@nicodjimenez Understand that the parsing and stuff in Gamma is extremely basic - it's stuff I did as a sophomore or junior in high school. If you're looking for something more sophisticated, you won't find it pre-written (in Gamma at least). Gamma sees the "integrate" (I think via TopCallVisitor) and converts the input to just integrate(x) in this case, I think. SymPy itself can parse all of this perfectly - it's the postprocessing Gamma does that is causing problems. If you just want the parsing, you should stick with parse_expr and maybe treat Gamma as a source of examples.