Matplotlib.axes.Axes.set_ylim() in Python

Last Updated : 19 Apr, 2020

Matplotlib is a library in Python and it is numerical - mathematical extension for NumPy library. The Axes Class contains most of the figure elements: Axis, Tick, Line2D, Text, Polygon, etc., and sets the coordinate system. And the instances of Axes supports callbacks through a callbacks attribute.

matplotlib.axes.Axes.set_ylim() Function:

The Axes.set_ylim() function in axes module of matplotlib library is used to set the y-axis view limits.

Syntax: Axes.set_ylim(self, bottom=None, top=None, emit=True, auto=False, *, ymin=None, ymax=None) Parameters: This method accepts the following parameters.

bottom : This parameter is the bottom ylim in data coordinates

top : This parameter is the top ylim in data coordinates

emit : This parameter is used to notify observers of limit change.

auto : This parameter is used to turn on autoscaling of the x-axis.

ymin, ymax: These parameter are equivalent to bottom and top and it is an error to pass both ymin and bottom or ymax and top.

Returns:This method returns the following

bottom, top:This returns the new y-axis limits in data coordinates.

Below examples illustrate the matplotlib.axes.Axes.set_ylim() function in matplotlib.axes: Example 1:

Python3

# Implementation of matplotlib function
from matplotlib.widgets import Cursor
import numpy as np
import matplotlib.pyplot as plt


np.random.seed(19680801)

fig, ax = plt.subplots(facecolor ='# A0F0CC')

x, y = 4*(np.random.rand(2, 100) - .5)
ax.plot(x, y, 'g')
ax.set_ylim(-3, 3)

cursor = Cursor(ax, useblit = True, color ='red',
                linewidth = 2)
    
ax.set_title('matplotlib.axes.Axes.set_ylim() Example\n',
             fontsize = 14, fontweight ='bold')
plt.show()

Output:

Example 2:

Python3

# Implementation of matplotlib function
import matplotlib.pyplot as plt
import numpy as np

fig1, ax1 = plt.subplots()
fig2, ax2 = plt.subplots()
ax1.set(xlim =(-0.5, 1.5), ylim =(-0.5, 1.5),
               autoscale_on = False)
ax2.set(xlim =(0.5, 0.75), ylim =(0.5, 0.75),
               autoscale_on = False)

x, y, s, c = np.random.rand(4, 200)
s *= 200

ax1.scatter(x, y, s, c)
ax2.scatter(x, y, s, c)


def GFG(event):
    if event.button != 1:
        return
    x, y = event.xdata, event.ydata
    ax2.set_xlim(x - 0.1, x + 0.1)
    ax2.set_ylim(y - 0.1, y + 0.1)
    fig2.canvas.draw()

fig1.canvas.mpl_connect('button_press_event', GFG)   
ax1.set_title('matplotlib.axes.Axes.set_ylim()\
 Example\n Original Window ',
             fontsize = 14, fontweight ='bold')
ax2.set_title('Zoomed window ',
             fontsize = 14, fontweight ='bold')
plt.show()