Brian Blais wrote: > Hello, > > In my attempt to learn python, migrating from matlab, I have the following > problem. > Here is what I want to do, (with the wrong syntax): > > from numpy import * > > t=arange(0,20,.1) > x=zeros(len(t),'f') > > idx=(t>5) > tau=5 > x[idx]=exp(-t[idx]/tau) # <---this line is wrong (gives a TypeError)
Hi Brian, Just to let you know, you are more likely to get good answers by mailing [EMAIL PROTECTED] then posting to this list. The indexing technique you are using is actually fine. The trouble you are having is that t is a double-precision array (and thus so is exp(-t[idx]/tau) while x is a single-precision array. Compare: x.dtype.name t.dtype.name Because you are trying to store something with greater precision into an array with less precision you get a TypeError. So, either change x to be double precision: x = zeros(len(t), float) #the default Python float is doubleprecision or change t to be single precision: t = arange(0,20,.1,dtype=single) Good luck, -Travis -- http://mail.python.org/mailman/listinfo/python-list
