Thanks. That sounds like it should help a lot. Finding meaningful examples anywhere hasn't been easy. I thought I'd look through Amazon for books on Python and scientific uses. I found almost all were written by authors outside the US, and none seemed to talk about items like matplotlib. Ezdraw or something like that was often cited. I'm definitely in a learning stage, and much of what I need is in graphics to support some data analysis that I'm doing.
Glad to hear it can gather bins into groups. It would be very disappointing if such a mechanism did not exist. In the distant past, I've all too often had to write my own histogram programs for this, FORTRAN, etc. My data is from a 640x480 collection of b/w pixels, which a processor has binned from 0-255, so I don't want repeat doing a histogram on 307K data points. Vincent Schut wrote: > Wayne Watson wrote: > >> I have a list that already has the frequencies from 0 to 255. However, >> I'd like to make a histogram that has say 32 bins whose ranges are 0-7, >> 8-15, ... 248-255. Is it possible? >> >> > Wayne, > > you might find the 'numpy example list with doc' webpage quite > informative... http://www.scipy.org/Numpy_Example_List_With_Doc (give it > some time to load, it's pretty large...) > For new users (I was one once...) it usually takes some time to find the > usual suspects in numpy/scipy help and docs... This one page has really > become unvaluable for me. > > It gives you the docstrings for numpy functions, often including some > example code. > > If you check out the histogram() function, you'll see it takes a 'bins=' > argument: > > bins : int or sequence of scalars, optional > If `bins` is an int, it defines the number of equal-width > bins in the given range (10, by default). If `bins` is a sequence, > it defines the bin edges, including the rightmost edge, allowing > for non-uniform bin widths. > > So, if your bins are known, you can pass it to numpy.histogram, either > as number-of-bins (if equal width), if necessary combined with the > 'range=' parameter to specify the range to divide into equal bins, or as > bin edges (e.g. in your case: (0, 8, 16, ... 256) or > numpy.linspace(0,256,33) which will give you this range nicely. > > If you don't specify the 'range=' parameter, it will check the min and > max from your input data and use that as lower and upper bounds. > > Good luck learning numpy! :) > > Vincent. > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion > > -- Wayne Watson (Watson Adventures, Prop., Nevada City, CA) (121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time) Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet 350 350 350 350 350 350 350 350 350 350 Make the number famous. See 350.org The major event has passed, but keep the number alive. Web Page: <www.speckledwithstars.net/> _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
