Feb. 26, 2004
1:18 p.m.
On Wednesday 2004-02-25 19:23, Tony Vignaux wrote:
Raymond,
You asked:
* Is there a way to compute the standard deviation without multiple passes over the data (one to compute the mean and a second to sum the squares of the differences from the mean?
I do not understand the problem in getting stdev in a single pass. Perhaps I not understood your problem. If you have a series of values you merely have to calculate their sum and sum-of-squares and use the usual formula.
The trouble with that is that it's numerically horrible. There are better ways, some of which were discussed in python-dev a few weeks ago. -- g