I was wondering if there was a way to “guide” sympy in performing trig
identities to get the output into a specific form? Below, I go into detail
and have attached a working version of the file for reference.
In the expression of P, the coefficients D, F, G, H, and J are assumed to
be real valued. I have left some commented print statements to show the
different simplify options I have tried. I have performed this calculation
by hand and I know there are several trig substitutions that need to be
made in order to get the final expression in the form that I would like.
That form is to get rid of all powers of trig functions greater than 1 by
appropriate substitutions. Of course, I cannot expect sympy to know that I
want things in this form so I am not surprised when the different simplify
statements do not give me that form. I was wondering what would be the
best way to guide sympy in order to get the final output of P to be in the
following form:
K + Lsin(x) + Mcos(x) + Nsin(2x) + Qcos(2x) + Rsin(3x) + Scos(3x) +
Tsin(4x) + Vcos(4x)
Where K, L, M, N, Q, R, S, T, and V are now combinations of the original D,
F, G, H, and J.
By the way, I am not as concerned now about the coefficients as I am
getting rid of the higher powers of the trig functions. Although if people
would like to weigh in on that, that would be great. If more detail is
needed, please let me know and I’d be happy to provide it.
--
You received this message because you are subscribed to the Google Groups
"sympy" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sympy.
For more options, visit https://groups.google.com/groups/opt_out.
from sympy import *
#define all symbols
D = Symbol('D')
F = Symbol('F')
G = Symbol('G')
H = Symbol('H')
J = Symbol('J')
x = Symbol('x')
#write out equations
P = (D + F*sin(x) + G*cos(x) + H*sin(2*x) + J*cos(2*x))**2
#print expand(P, trig=True)
#print trigsimp(expand(P, trig=True))
#print simplify(expand(P, trig=True))
