Change x-axis ticks to custom strings

Question

I want to change the x-axis ticklabels to custom strings, but the following does not work. How can I set the ticklabels to ["one", "two", "three"]?

from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
import matplotlib.pyplot as plt

def pushButtonClicked(self):
        code = self.lineEdit.text()
       
       
        x=["one","two","three"]
        l=[1,2,3]
        y=[2,3,4]
        ax = self.fig.add_subplot(111)
       
        print(1)
        
        ax.plot(l, y, label='DeadPopulation')
        ax.xticks(l,x)
        print(IntroUI.g_sortArrayDeadcnt)
      
        ax.legend(loc='upper right') 
        ax.grid() 
        self.canvas.draw()

Answer 1

New in matplotlib 3.5.0

Use the labels param of ax.set_xticks to set ticks and labels simultaneously:

x = [1, 2, 3]
y = [10, 0, 4]
l = ['one', 'two', 'three']

fig, ax = plt.subplots()
ax.plot(x, y)
ax.set_xticks(x, labels=l)
#                ^^^^^^

Note that plt.xticks has always had this functionality:

plt.plot(x, y)
plt.xticks(x, labels=l)

Using ax.set_xticklabels is now discouraged, but the method will remain for backward compatibility.

Answer 2

I assume you just want to set the ticks to be equal to ['one', 'two', 'three']?

To do this, you need to use set_xticks() and set_xticklabels():

from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
import matplotlib.pyplot as plt

def pushButtonClicked(self):
        code = self.lineEdit.text()


        x=["one","two","three"]
        l=[1,2,3]
        y=[2,3,4]
        ax = self.fig.add_subplot(111)

        print(1)

        ax.plot(l, y, label='DeadPopulation')

        # Set the tick positions
        ax.set_xticks(l)
        # Set the tick labels
        ax.set_xticklabels(x)

        print(IntroUI.g_sortArrayDeadcnt)

        ax.legend(loc='upper right') 
        ax.grid() 
        self.canvas.draw()

Minimal example

import matplotlib.pyplot as plt
f, ax = plt.subplots()

x = ['one', 'two', 'three']
l = [1, 2, 3]
y = [2, 3, 4]

ax.plot(l,y)
ax.set_xticks(l)
ax.set_xticklabels(x)

plt.show()

Here is how it would look like: