per freem wrote: > hi all, > > i'm getting very strange behavior from the matplotlib 'plot' function > when attempting to plot multiple lines. i have a series of x, y data > points that are being generated in a loop and i want to simply plot > each of them on the same plot. my code is: > > import matplotlib > matplotlib.use('PDF') > import matplotlib.pyplot as plt > from matplotlib import rc > rc('font',**{'family':'sans-serif','sans-serif':['Helvetica']}) > plt.rcParams['ps.useafm'] = True > rc('font',**{'family':'sans-serif','sans-serif':['Helvetica']}) > > my_fig = plt.figure(figsize=(6,5), dpi=100) > num_lines = 3 > > for n in range(0, num_lines): > print "Printing line %d" %(n+1) > x = range(0, 100) > y = (ones(100)*(n+1)) > plt.plot(x, y) > > plt.savefig('plot_example.pdf') > > when I do this, it only plots the last line (a horizontal line at y = > 3). how can i get to actually plot all three lines? > > more strangely, it shows *stochastic* behavior: sometimes when i run > the code, it generates a green line at y = 3, and other times a blue > line. from plot to plot, the upper bound of the y axis changes, > sometimes being 3.15, sometimes 3.2. i'm not sure why it is doing that. > > how can i get it to simply add whatever i plot in the body of the > 'for' loop to the same graph? i tried adding plt.plot() after my call > to plt.plot but that did not fix it. > > thank you.
Per: The plots are there, you just can't see them because the y-axis has been auto-scaled so that the first and last lines lie on the top and bottom of the plot window. Just add plt.ylim(0,4) after the loop and you will see all three lines. -Jeff ------------------------------------------------------------------------------ Enter the BlackBerry Developer Challenge This is your chance to win up to $100,000 in prizes! For a limited time, vendors submitting new applications to BlackBerry App World(TM) will have the opportunity to enter the BlackBerry Developer Challenge. See full prize details at: http://p.sf.net/sfu/Challenge _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users