Thanks for the information. Unfortunately, this CDF doesn't look like the CDF that we see in other published papers. I'm not sure what they are done with... But they have a thin line that shows the integral of all measurements, rather than a bar graph. The problem with a bar graph is that different bin widths give different results.
GNU Plot seems to do a decent job, as can e seen at http:// chem.skku.ac.kr/~wkpark/tutor/gnuplot/gpdocs/prob.htm. But there should be a way to do this nicely with matplotlib, right? On Mar 18, 2007, at 12:41 PM, John Hunter wrote: > On 3/17/07, Simson Garfinkel <[EMAIL PROTECTED]> wrote: >> Hi. I haven't been active for a while, but now I have another paper >> that I need to get out... > > Glad to have you back... > >> Anyway, I need to draw a cumulative distribution function, as the >> reviewers of my last paper really nailed me to the wall for including >> histograms instead of CDFs. Is there any way to plot a CDF with >> matplotlib? > > For analytic cdfs, see scipy.stats. I assume you need an empirical > cdf. You can use matplotlib.mlab.hist to compute the empirical pdf > (use normed=True to return a PDF rather than a frequency count). Then > use numpy.cumsum to do the cumulative sum of the pdf, multiplying by > the binsize so it approximates the integral. > > import matplotlib.mlab > from pylab import figure, show, nx > > x = nx.mlab.randn(10000) > p,bins = matplotlib.mlab.hist(x, 50, normed=True) > db = bins[1]-bins[0] > cdf = nx.cumsum(p*db) > > fig = figure() > ax = fig.add_subplot(111) > ax.bar(bins, cdf, width=0.8*db) > show() > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
