Python matplotlib - errorbar None values in series

Question

I was trying to plot a series with error bars. The series may contain None values. When not using the errors - the series is plotted with no error. When trying to plot with the error bars - I get this error:

My code is:

x = [10.4, 11.12,11.3,None, 10.2,11.3]
y = [0.3, 1.2, 0.7, None, 1.1, 0.4]
y_err = [0.01, 0.04, 0.07, None, 0.01, 0.05] 

plt.plot(x,y, 'o', color='r') # this one works. I get a plot with 5 points. The null point is skipped
plt.errorbar(x,y,yerr=y_err) # this one doesn't work

The error I get is:

 TypeError: unsupported operand type(s) for -: 'NoneType' and 'NoneType'

Is there any way to skip the null values in a series?

Thanks!

And how big are the series normally? If you can simply filter out all the `None` values before plotting this could be easily done. Question is: do you have time and memory to do this? — Aleksander Lidtke, Jun 11 '14 at 12:46
@Alexander - Pre filtering may be time consuming, and I was hoping to avoid that... — user3730002, Jun 11 '14 at 12:52

score 6 · Accepted Answer · edited May 23 '17 at 10:33

6

Try using NaN rather than "None".

x = [10.4, 11.12,11.3,float('NaN'), 10.2,11.3]
y = [0.3, 1.2, 0.7, float('NaN'), 1.1, 0.4]
y_err = [0.01, 0.04, 0.07, float('NaN'), 0.01, 0.05] 
plt.plot(x,y, 'o', color='r')
plt.errorbar(x,y,yerr=y_err)

Assigning a variable NaN in python without numpy

edited May 23 '17 at 10:33

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answered Jun 11 '14 at 13:02

MattQ

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Python matplotlib - errorbar None values in series

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