Matplotlib add a specific tick presenting axis max - multiple scales single observation

Question

Trying to plot observations respectively to multiple scales per observation, I've managed to produce the following plot:

However I would like to add a tick presenting the y-max value in each scale, regardless of the gap between it and the previous tick. An example of a such plot is presented below . It is produced when the y-max is a multiple of the ticking interval.

Thanks, F.

Here is the code used to produce these example.

import numpy as np
import pylab as pl
import matplotlib as plt
import matplotlib.ticker as ticker
import matplotlib.transforms

def add_scales(fig, axes, scales, subplot_reduction_factor=0.1, margin_size=50):
    nb_scales = len(scales)
    b,l,w,h = zoom_ax.get_position().bounds

    _, ymax = axes.get_ylim()

    # Saves some space to the right so that we can add our scales
    fig.subplots_adjust(right=1-(subplot_reduction_factor)*nb_scales)

    for (n, (vmin, vmax, color, label, alignment)) in enumerate(scales):

        # Adjust wrt. the orignial figure's scale 
        nax = fig_zoom.add_axes((b,l,w,(h * alignment) / ymax))
        nax.spines['right'].set_position(('outward', -40+n*margin_size))
        nax.set_ylim((vmin,vmax))

        # Move ticks and label to the right
        nax.yaxis.set_label_position('right')
        nax.yaxis.set_ticks_position('right')

        # Hides everything except yaxis
        nax.patch.set_visible(False)
        nax.xaxis.set_visible(False)
        nax.yaxis.set_visible(True)
        nax.spines["top"].set_visible(False)
        nax.spines["bottom"].set_visible(False)

        # Color stuff
        nax.spines['right'].set_color(color)
        nax.tick_params(axis='y', colors=color)
        nax.yaxis.set_smart_bounds(False)
        #nax.yaxis.label.set_color(color)

        if label != None:
            nax.set_ylabel(None)

if __name__ == '__main__':

    a=(np.random.normal(10,5,100))

    a=np.linspace(0,100,100) 
    c=np.linspace(0,80, 100)
    d=np.linspace(0,40,100)


    fig_zoom = plt.pyplot.figure()
    zoom_ax = fig_zoom.add_subplot(1,1,1)


    zoom_ax.plot(a,c)
    zoom_ax.plot(a,d)
    zoom_ax.set_title('Zoom')
    zoom_ax.set_xlabel('A')
    zoom_ax.set_ylabel('B')
    zoom_ax.set_ylim((0,100))
    zoom_ax.grid()
    add_scales(fig_zoom, 
               zoom_ax, [(0,.55,'green',None,40),
                          (0,.85,'blue',None,80)])

    fig_zoom.savefig(open('./test.svg','w'),format='svg')

Answer 1

You can set the highest ytick value to your maximum. If the second highest ytick value and your maximum are very close, the labels might clutter.

Try adding this to your loop:

tcks = nax.get_yticks()
tcks[-1] = vmax
nax.set_yticks(tcks)