Hi,
I have recently installed sage from source and am trying to implement
fourier transforms. I wrote a piece of sage code which does the job for
some function f.
var('t', 'k','x','a')
assume(a > 0, k > 0)
# Define the function that that we will transform
f = e^ - (a * abs(x))
# Apply the transform
def fourier(f,x,k):
F = (f * e ^ (-i * k * x)).integral(x, -oo,oo)
return(F.full_simplify())
print(fourier(f,x,k))
I then added a function in /src/sage/calculus.py, (E and I because capitals
because of how they were imported)
def fourier(f, x, k):
F = f * E ** (-I * k * x)
return (F).integral(x, -oo,oo).full_simplify()
and I got some errors; first the constants e & i were not defined. I found
e easily using the e?? functionality of sage but finding how to import i
took a little more time because i?? didn't direct me to pynac.py where it
is defined. Now I have a slightly more tricky error which will take a bit
of reading on my part to debug (.
Traceback (most recent call last):
File "test.sage.py", line 17, in <module>
print(f.fourier(x,k))
File "sage/symbolic/expression.pyx", line 11365, in
sage.symbolic.expression.Expression.fourier
(/home/tom/sage/src/build/cythonized/sage/symbolic/expression.cpp:60975)
File
"/home/tom/sage/local/lib/python2.7/site-packages/sage/calculus/calculus.py",
line 1413, in fourier
ex = f * E ** (-I * var(k) * var(x))
File "sage/symbolic/expression.pyx", line 3572, in
sage.symbolic.expression.Expression.__pow__
(/home/tom/sage/src/build/cythonized/sage/symbolic/expression.cpp:22299)
File "sage/symbolic/expression.pyx", line 2724, in
sage.symbolic.expression.Expression.coerce_in
(/home/tom/sage/src/build/cythonized/sage/symbolic/expression.cpp:19690)
File "sage/structure/parent_old.pyx", line 239, in
sage.structure.parent_old.Parent._coerce_
(/home/tom/sage/src/build/cythonized/sage/structure/parent_old.c:4448)
File "sage/structure/parent.pyx", line 1330, in
sage.structure.parent.Parent.coerce
(/home/tom/sage/src/build/cythonized/sage/structure/parent.c:10924)
File "sage/structure/element.pxd", line 17, in
sage.structure.element.parent_c
(/home/tom/sage/src/build/cythonized/sage/structure/parent.c:28387)
TypeError: descriptor 'parent' of 'sage.structure.element.Element' object
needs an argum
Is there a better way for me to change my sage code to python code? perhaps
a piece of code that tells me which sage dependencies I am using? or can
you submit straight up sage code and not even bother to convert it to
python?
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