Change values on matplotlib imshow() graph axis
Say I have some input data:
data = np.random.normal(loc=100,scale=10,size=(500,1,32)) hist = np.ones((32,20)) # initialise hist for z in range(32): hist[z],edges = np.histogram(data[:,0,z],bins=np.arange(80,122,2))
I can plot it using
However, the x-axis values do not match the input data (i.e. mean of 100, range from 80 to 122). Therefore, I'd like to change the x-axis to show the values in
I have tried:
ax = plt.gca() ax.set_xlabel([80,122]) # range of values in edges ... # this shifts the plot so that nothing is visible
ax.set_xticklabels(edges) ... # this labels the axis but does not centre around the mean:
Any ideas on how I can change the axis values to reflect the input data I am using?
I would try to avoid changing the
xticklabels if possible, otherwise it can get very confusing if you for example overplot your histogram with additional data.
Defining the range of your grid is probably the best and with
imshow it can be done by adding the
extent keyword. This way the axes gets adjusted automatically. If you want to change the labels i would use
set_xticks with perhaps some formatter. Altering the labels directly should be the last resort.
fig, ax = plt.subplots(figsize=(6,6)) ax.imshow(hist, cmap=plt.cm.Reds, interpolation='none', extent=[80,120,32,0]) ax.set_aspect(2) # you may also use am.imshow(..., aspect="auto") to restore the aspect ratio