Showing the starting value on log scale other than the power of 10 using matplotlib-CodePudding

I have been facing the challenge of showing the starting value on the x-axis with a logarithmic scale. which is other than the power of 10. Unfortunately, I cannot find a way to show this starting value on x-axis. I am using matplotlib and the major constraint is that I have to keep the formatting of the graph as it is therefore please suggest a way that solves the issue without changing the existing formatting.

Code:

   plt.plot(xdata,ydata)
   plt.xscale("log")
   plt.xlim([0.15, 30])
   plt.ylim([-10, 80])
   plt.minorticks_on()
   plt.grid(which = 'minor', linestyle=':', linewidth = '0.5', color = 'black')
   plt.grid(b = True, which = 'major', linestyle='-', linewidth = '1', color = '#666666')
   plt.show()

Current output

Desired output

CodePudding user response：

If you don't mind having the intermediate tick labels in regular format (not engineering format), this could work:

import matplotlib.pyplot as plt
from matplotlib.ticker import ScalarFormatter
import numpy as np


xdata = np.logspace(np.log10(0.15), np.log10(30))
ydata = np.random.random(len(xdata))

fig, ax = plt.subplots()
ax.plot(xdata, ydata, '-s')
ax.set_xscale("log")

Once you have the plot, you can manually set the ticks with:

ax.set_xticks([0.15, 1, 10, 30])
ax.get_xaxis().set_major_formatter(ScalarFormatter())

to get: