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 | 1 | initial version |
P.subs() should work only for the variables of the polynomials, ie. x and y.
a is a not a polynomial variable but rather a parameter, which polynomial coefficients depend on. Hence, you need to perform symbolic substitution in each of the coefficients. For example, this will do the job:
R.<x, y> = SR[]
a = SR.var('a')
P = a*x
print( sum(map(lambda t: t[0].subs({a:1})*t[1], P)) )
| | 2 | No.2 Revision |
P.subs() should work only for the variables of the polynomials, ie. x and y.
a is a not a polynomial variable but rather a parameter, which polynomial coefficients depend on. Hence, you need to perform symbolic substitution in each of the coefficients. For example, this will do the job:
R.<x, y> = SR[]
a = SR.var('a')
P = a*x
print( sum(map(lambda t: t[0].subs({a:1})*t[1], P)) )
or (as suggested by @achrzesz):
print( P.map_coefficients(lambda t: t.subs({a:1})) )
