问题
I'm facing some problems in the alignment of the ticks of two different y-axes with the first characterized by a linear range and the second by a non linear range as depicted in the following picture.
HS, TMN = np.meshgrid(hs, period)
r = function(HS, TMN)
cax = plt.contourf(HS, TMN, np.log10(HS), cmap=plt.cm.RdYlGn_r)
ax = plt.gca()
ax2 = ax.twinx()
ticks2 = get_y2values(ax.get_yticks()) # Non linear function
ax2.yaxis.set_major_locator(mpl.ticker.FixedLocator(ticks))
ax2.set_ylim([0, 700])
ax.grid()
ax.set_ylabel('Y1', fontsize=14)
ax2.set_ylabel('Y2', fontsize=14)
plt.show()
More precisely, the right axis requires a different scale from the one on the left. And as final outcome, the idea is to have ticks values on the left aligned with the ticks values on the right (due to the non-linear function depicted below). E.g.: the value 8.08 from Y1 aligned with 101.5; 16.07 aligned with 309.5...
The new scale is required in order to insert new plot in the new scale.
回答1:
As suggested in the comments the definition of a new scale works perfectly.
Referring to the SegmentedScale defined at the following link, the code that worked for me is the following:
hs = np.linspace(0.1, 15, 1000) # [meters]
period = np.linspace(0.1, 35, 1000) # [seconds]
HS, TMN = np.meshgrid(hs, period)
cax = plt.contourf(HS, TMN, np.log10(HS), cmap=plt.cm.RdYlGn_r)
ax1 = plt.gca()
ax2 = ax.twinx()
ticks = get_y2values(ax1.get_yticks()) # Non linear function
ax2.set_yscale('segmented', points=ticks)
ax1.grid()
ax1.set_yticks(ax1.get_yticks())
ax2.set_yticks(ticks)
ax1.set_ylabel('Y1', fontsize=14)
ax2.set_ylabel('Y2', fontsize=14)
plt.show()
If it is necessary to add new plots on the ax2 axis, it is required to do the plot before the application of the new custom scale.
来源：https://stackoverflow.com/questions/49874482/align-twinx-with-second-axis-with-non-linear-scale