Hi Tom, Yes, I would find the version you suggested clearer. I mean now that I know how to read it the old version seems quite logical, but if it would have been written the way you suggested I would not have made my misinterpretation.
Thank you for your help, Cheers, Markus Am 2013-02-09 14:04, schrieb Thomas Caswell: > My default interpretation of errors is always relative to the value > because that is how they are reported (100+10-20 not 100+110-80). > > (got your 2nd email while writing this) > > Would you find this clearer? Maybe xerr and yerr should be split up > > xerr/yerr: [ scalar | N, Nx1, or 2xN array-like ] > If a scalar number, len(N) array-like object, or an Nx1 array-like > object, errorbars are drawn x/y +/- value. > If a sequence of shape 2xN, errorbars are drawn at x/y - row1 and x/y + row2 > > Tom > > On Sat, Feb 9, 2013 at 12:49 PM, Markus Haider <markus.hai...@uibk.ac.at> > wrote: >> Hi Tom, >> >> Thank you very much for your answer. Indeed this solves my problem. However, >> I was wondering if the documentation on this is correct. >> At >> http://matplotlib.org/api/axes_api.html?highlight=errorbar#matplotlib.axes.Axes.errorbar >> it says: >> >> xerr/yerr: [ scalar | N, Nx1, or 2xN array-like ] >> If a scalar number, len(N) array-like object, or an Nx1 array-like object, >> errorbars are drawn +/- value. >> If a sequence of shape 2xN, errorbars are drawn at -row1 and +row2 >> >> This sounds to me that for a 2xN argument it should be drawn from the actual >> supplied value, or would you interpret this differently? >> >> Thanks, >> Markus >> >> Am 2013-02-08 22:02, schrieb Thomas Caswell: >> >>> The bar is drawn from `y - yerr_low` to `y + yerr_upp` >>> >>> ax.errorbar(x + .5,y,yerr=[[y - yerr_low],[yerr_upp - >>> y]],fmt='s',markersize=4) >>> >>> will get you what you want. >>> >>> Tom >>> >>> On Fri, Feb 8, 2013 at 8:41 PM, Markus Haider <markus.hai...@uibk.ac.at> >>> wrote: >>>> Hi, >>>> >>>> I think I have a problem with errorbars in a log plot. The problem is >>>> reproducible through the enclosed errorbar_log.py file. As you can see I >>>> plot a point with y = 10**(-5) and I want the errorbars drawn from >>>> 10**(-5.5) to 10**(-4.5) which should be symmetric in this plot but >>>> isn't. >>>> >>>> Here is the content of my errorbar_log.py file: >>>> >>>> #!/usr/bin/python >>>> import numpy as np >>>> import matplotlib.pyplot as plt >>>> >>>> fig = plt.figure() >>>> ax = fig.add_subplot(111) >>>> x = 0.0 >>>> y = 10**(-5.0) >>>> yerr_low = 10**(-5.5) >>>> yerr_upp = 10**(-4.5) >>>> ax.errorbar(x,y,yerr=[[yerr_low],[yerr_upp]],fmt='o',markersize=4) >>>> ax.set_xlim(-1.0,1.0) >>>> ax.set_ylim(1E-6,1E-3) >>>> ax.set_yscale('log') >>>> plt.savefig('errorbar.png') >>>> >>>> --------------------------------------------- >>>> >>>> 10**(-5.5) = 3.162277660168379e-06 >>>> and 10**(-4.5) = 3.1622776601683795e-05 >>>> >>>> but you can see that the lower boundary is not at the calculated value. >>>> <http://matplotlib.1069221.n5.nabble.com/file/n40412/errorbar.png> >>>> >>>> >>>> Do I misunderstand the behaviour of the errorbar function or is this a >>>> bug? >>>> >>>> Cheers, >>>> Markus >>>> >>>> >>>> >>>> -- >>>> View this message in context: >>>> http://matplotlib.1069221.n5.nabble.com/Errorbar-problem-tp40412.html >>>> Sent from the matplotlib - devel mailing list archive at Nabble.com. >>>> >>>> >>>> ------------------------------------------------------------------------------ >>>> Free Next-Gen Firewall Hardware Offer >>>> Buy your Sophos next-gen firewall before the end March 2013 >>>> and get the hardware for free! Learn more. >>>> http://p.sf.net/sfu/sophos-d2d-feb >>>> _______________________________________________ >>>> Matplotlib-devel mailing list >>>> Matplotlib-devel@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel >>> >>> >>> -- >>> Thomas Caswell >>> tcasw...@gmail.com >>> > > > -- > Thomas Caswell > tcasw...@gmail.com > ------------------------------------------------------------------------------ Free Next-Gen Firewall Hardware Offer Buy your Sophos next-gen firewall before the end March 2013 and get the hardware for free! Learn more. http://p.sf.net/sfu/sophos-d2d-feb _______________________________________________ Matplotlib-devel mailing list Matplotlib-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
