Chris Begert wrote:
Bonjour
I have three lists with 65 float items and would like to do the following sum:
L0 = ([sum(L0A[i]*cos(L0B[i]+L0C[i]*JME) for i in range(0,64,1))])
[...]
However, I always get this error:
TypeError: can't multiply sequence by non-int of type 'float'
Works for me:
>>> from math import cos
>>> L0A = [i for i in range(64)] # make up some data
>>> L0B = [2*i+3 for i in range(64)]
>>> L0C = [3*i-2 for i in range(64)]
>>> JME = 2
>>> L0 = ([sum(L0A[i]*cos(L0B[i]+L0C[i]*JME) for i in range(0,64,1))])
>>> L0
[39.022477151098606]
Please compare what you typed in your email with the code you are trying
to run. I think you will find that you have something like this by mistake:
([sum(L0A*cos(L0B[i]+L0C[i]*JME) for i in range(0,64,1))])
Notice that it has L0A*cos(...) instead of L0A[i]*cos(...).
Some other comments:
Why is the sum stored in a one-item list? I don't think you need either
of the two outer-most brackets, ([...]). That is:
L0 = sum(L0A[i]*cos(L0B[i]+L0C[i]*JME) for i in range(0,64,1))
You can simplify the call to range: range(0, 64, 1) is just a long way
of writing range(64):
L0 = sum(L0A[i]*cos(L0B[i]+L0C[i]*JME) for i in range(64))
Rather than explicitly specify the indexes used, a better solution is to
use zip() like this:
L0 = sum(a*cos(b+c*JME) for a,b,c in zip(L0A, L0B, L0C))
--
Steven
_______________________________________________
Tutor maillist - Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor
