如何在matplotlib python中删除刻度标签之间

Question

Im using matplotlib to create a graph, How can I remove ticks but keep the first and last ones only? I want to keep their effect though on drawing the grid on the inside of the plot. (remove only the labels to be precise)

Code

        plt.xlabel("Time [sec]")
        plt.ylabel("Load [kN]")
        plt.figure(figsize=(6,4.4))
        plt.xlim([0, 60])
        plt.grid(linestyle='dotted')
        plt.axis(linestyle="dotted")
        plt.tick_params(axis='y',rotation=90)
        ax1= plt.subplot()
        ax1.spines['right'].set_color('none')
        ax1.spines['bottom'].set_color('none')
        ax1.spines['left'].set_color('none')
        ax1.spines['top'].set_color('none')
        ax1.yaxis.set_major_formatter(FormatStrFormatter('%.3f'))
        ax1.tick_params(axis='both', which='major', labelsize=6,colors='#696969')
        ax1.tick_params(axis='both', which='minor', labelsize=6,colors='#696969')
        ax1.xaxis.set_tick_params(length=0,labelbottom=True)
        ax1.yaxis.set_tick_params(length=0,labelbottom=True)
        plt.plot(x,y,color='#696969',linewidth='0.5')
        plt.show()

Current Figure:

Goal:

Thanks.

Answer 1

You can use xticks and yticks to set the ticks you want on the x and y axes, passing to the functions the list of numbers (ticks) you want to be displayed. For example:

plt.yticks(np.arange(0, 450, step=50))

Answer 2

The tick positions define the positions of the grid. So, in the x-direction we would have one every 10. The labels can be set to an empty string, except the first and the last.

The most complicated part is forcing the first and last grid line to be visible. Due to rounding, sometimes they can fall outside the plot area. Adding an extra epsilon to the limits, should force these grid lines to be visible.

The padding for the x and ylabel can be set negative to bring them closer to the axis.

Note that the figure and the axis should be created before doing operations such as setting labels and grids. The easiest is to call fig, ax = plt.subplots() before any plotting-related commands.

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

# create some dummy data
x = np.linspace(0, 60, 500)
y = (np.sin(x / 5) + 1) * 450000 / 2

fig, ax1 = plt.subplots(figsize=(6, 4.4))

ax1.plot(x, y, color='#696969', linewidth='0.5')

xlims = (0, 60)
xlim_eps = xlims[1] / 200
# use some extra epsilon to force the first and last gridline to be drawn in case rounding would put them outside the plot
ax1.set_xlim(xlims[0] - xlim_eps, xlims[1] + xlim_eps)
xticks = range(xlims[0], xlims[1] + 1, 10)
ax1.set_xticks(xticks)  # the ticks define the positions for the grid
ax1.set_xticklabels([i if i in xlims else '' for i in xticks]) # set empty label for all but the first and last
ax1.set_xlabel("Time [sec]", labelpad=-8)  # negative padding to put the label closer to the axis

ylims = (0, 450)
ylim_eps = ylims[1] / 200
ax1.set_ylim(ylims[0] - ylim_eps, ylims[1] + ylim_eps)
yticks = range(ylims[0], ylims[1] + 1, 50)
ax1.set_yticks(yticks)
ax1.set_yticklabels([f'{i:.3f}' if i in ylims else '' for i in yticks])
ax1.tick_params(axis='y', rotation=90)
ax1.set_ylabel("Load [kN]", labelpad=-8)

ax1.grid(True, linestyle='dotted')
for dir in ['right', 'bottom', 'left', 'top']:
    ax1.spines[dir].set_color('none')
ax1.tick_params(axis='both', which='major', labelsize=6, colors='#696969', length=0)

plt.show()