xerr is +/- relative to the data: *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 at +/-value relative to the data.
If a sequence of shape 2xN, errorbars are drawn at -row1 and +row2 relative to the data. I think you want: xdat=10**data_x_log ax.errorbar(10**data_x_log,data_y,xerr=[xdat-error_x_lower,error_x_upper-xdat],ls='',marker='o') Cheers, Jody > On 7 Apr 2015, at 13:51 PM, Markus Haider <markus.hai...@uibk.ac.at> wrote: > > I have the error from a table which is in log units, and the error is > given to be symmetric in log space. > > Cheers, > Markus > > On 2015-04-07 16:40, Yuxiang Wang wrote: >> Typo - "standard deviation OR standard error of mean", not "OF". >> >> Sorry. >> >> Shawn >> >> >> On Tue, Apr 7, 2015 at 10:39 AM, Yuxiang Wang <yw...@virginia.edu> wrote: >>> If you error bars denote standard deviation of standard error of mean, >>> shouldn't they be non-symmetric in log scale? >>> >>> Shawn >>> >>> On Tue, Apr 7, 2015 at 10:11 AM, Markus Haider <markus.hai...@uibk.ac.at> >>> wrote: >>>> Hi, >>>> >>>> I am trying to make an errorbar plot with a logarithmic x-axis. I have >>>> symmetric errors in logspace, however if I plot them, the errors are not >>>> symmetric anymore, as you can see in the enclosed image. Am I >>>> misunderstanding something or is this a bug? >>>> >>>> Thanks for your help, >>>> Markus >>>> >>>> Here the code I used to produce the plot: >>>> >>>> import matplotlib.pyplot as plt >>>> >>>> import numpy as np >>>> >>>> data_x_log = np.array([13.0,15.0]) >>>> >>>> data_y = np.array([0.5,1]) >>>> >>>> error_x_log = np.array([0.5,1.]) >>>> >>>> error_x_lower = 10**(data_x_log-error_x_log) >>>> >>>> error_x_upper = 10**(data_x_log+error_x_log) >>>> >>>> fig = plt.figure() >>>> >>>> ax = fig.add_subplot(111) >>>> >>>> ax.errorbar(10**data_x_log,data_y,xerr=[error_x_lower,error_x_upper],ls='',marker='o') >>>> >>>> ax.set_xscale('log') >>>> >>>> ax.set_xlim([1E11,1E17]) >>>> >>>> ax.set_ylim([0,2]) >>>> >>>> plt.savefig('error.png') >>>> >>>> >>>> ------------------------------------------------------------------------------ >>>> BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT >>>> Develop your own process in accordance with the BPMN 2 standard >>>> Learn Process modeling best practices with Bonita BPM through live >>>> exercises >>>> http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_ >>>> source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF >>>> _______________________________________________ >>>> Matplotlib-users mailing list >>>> Matplotlib-users@lists.sourceforge.net >>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users >>>> >>> >>> >>> -- >>> Yuxiang "Shawn" Wang >>> Gerling Research Lab >>> University of Virginia >>> yw...@virginia.edu >>> +1 (434) 284-0836 >>> https://sites.google.com/a/virginia.edu/yw5aj/ >> >> > > > ------------------------------------------------------------------------------ > BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT > Develop your own process in accordance with the BPMN 2 standard > Learn Process modeling best practices with Bonita BPM through live exercises > http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_ > source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF > _______________________________________________ > Matplotlib-users mailing list > Matplotlib-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-users -- Jody Klymak http://web.uvic.ca/~jklymak/ ------------------------------------------------------------------------------ BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT Develop your own process in accordance with the BPMN 2 standard Learn Process modeling best practices with Bonita BPM through live exercises http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_ source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users