Found 1034 Articles for Matplotlib

Linear regression with Matplotlib/Numpy

Rishikesh Kumar Rishi
Updated on 16-Mar-2021 10:35:45

8K+ Views

To get a linear regression plot, we can use sklearn’s Linear Regression class, and further, we can draw the scatter points.StepsGet x data using np.random.random((20, 1)). Return random floats in the half-open interval[20, 1).Get the y data using np.random.normal() method. Draw random samples from a normal (Gaussian) distribution.Get ordinary least squares Linear Regression, i.e., model.Fit the linear model.Return evenly spaced numbers over a specified interval, using linspace() method.Predict using the linear model, using predict() method.Create a new figure, or activate an existing figure, with a given figsize tuple (4, 3).Add an axis to the current figure and make it the ... Read More

What's the fastest way of checking if a point is inside a polygon in Python?

Rishikesh Kumar Rishi
Updated on 16-Mar-2021 10:33:54

5K+ Views

First, we will create a polygon using the mplPath.Path method and to check whether a given point is in the polygon or not, we will use the method, poly_path.contains_point.StepsCreate a list of points to make the polygon.Create a new path with the given vertices and codes, using mplPath.Path().Check if point (200, 100) exists in the polygon or not, using contains_point() method. Return whether the (closed) path contains the given point. => TrueCheck if point (1200, 1000) exists in the polygon or not, using contains_point() method. Return whether the (closed) path contains the given point. => FalseExampleimport matplotlib.path as mplPath import ... Read More

Row and column headers in Matplotlib's subplots

Rishikesh Kumar Rishi
Updated on 16-Mar-2021 10:18:23

366 Views

Using the subplot method, we can configure the number of rows and columns. nrows*nclos will create number positions to draw a diagram.StepsNumber of rows = 2, Number of columns = 1, so total locations are: 2*1 = 2.Add a subplot to the current figure, nrow = 2, ncols = 1, index = 1.Add a subplot to the current figure, nrow = 2, ncols = 1, index = 2.Using plt.show(), we can show the figure.Examplefrom matplotlib import pyplot as plt row_count = 2 col_count = 1 index1 = 1 # no. of subplots are: row*col, index is the position ... Read More

How to change backends in Matplotlib?

Rishikesh Kumar Rishi
Updated on 16-Mar-2021 10:18:47

1K+ Views

We can override the backend value using atplotlib.rcParams['backend'] variable.StepsUsing get_backend() method, return the name of the current backend, i.e., default name.Now override the backend name.Using get_backend() method, return the name of the current backend, i.e., updated name.Exampleimport matplotlib print("Before, Backend used by matplotlib is: ", matplotlib.get_backend()) matplotlib.rcParams['backend'] = 'TkAgg' print("After, Backend used by matplotlib is: ", matplotlib.get_backend())OutputBefore, Backend used by matplotlib is: GTK3Agg After, Backend used by matplotlib is: TkAgg Enter number of bars: 5

How to give a Pandas/Matplotlib bar graph custom colors?

Rishikesh Kumar Rishi
Updated on 16-Mar-2021 10:19:16

3K+ Views

To make a custom color, we can create a hexadecimal string. From it, we can make different sets of color representation and can pass them into the scatter method to get the desired output.Using the set_color method, we could set the color of the bar.StepsTake user input for the number of bars.Add bar using plt.bar() method.Create colors from hexadecimal alphabets by choosing random characters.Set the color for every bar, using set_color() method.To show the figure we can use plt.show() method.Examplefrom matplotlib import pyplot as plt import random bar_count = int(input("Enter number of bars: ")) bars = plt.bar([i for ... Read More

How to generate random colors in Matplotlib?

Rishikesh Kumar Rishi
Updated on 16-Mar-2021 10:21:32

2K+ Views

To make a custom color, we can create a hexadecimal string. From it, we can make different sets of color representation and can pass into the scatter method to get the desired output.StepsTake an input from the user for the number of colors, i.e., number_of_colors = 20.Use Hexadecimal alphabets to get a color.Create a color from (step 2) by choosing a random character from step 2 data.Plot scatter points for step 1 input data, with step 3 colors.To show the figure, use plt.show() method.Exampleimport matplotlib.pyplot as plt import random number_of_colors = int(input("Please enter number of colors: ")) hexadecimal_alphabets ... Read More

Change values on matplotlib imshow() graph axis

Rishikesh Kumar Rishi
Updated on 16-Mar-2021 10:21:58

3K+ Views

First, we can initialize an array matrix and pass it into the imshow method that can help to get the image for the given matrix.StepsCreate a 2D Array i.e., img.Using imshow() method, display the data as an image, i.e., on a 2D regular raster.Use plt.show() method to show the figure.Exampleimport matplotlib.pyplot as plt img = [[1, 2, 4, 5, 6, 7],       [11, 12, 14, 15, 16, 17],       [101, 12, 41, 51, 61, 71],       [111, 121, 141, 151, 161, 171]] plt.imshow(img, extent=[0, 5, 0, 5]) plt.show()Output

Defining the midpoint of a colormap in Matplotlib

Rishikesh Kumar Rishi
Updated on 16-Mar-2021 10:11:07

264 Views

Using plt.subplots(1, 1) method, we can create fig and axis. We can use fig.colorbar to make the color bar at the midpoint of the figure.StepsUsing mgrid() method, `nd_grid` instance which returns an open multi-dimensional "meshgrid".Create Z1, Z2 and Z data.Create fig and ax variables using subplots method, where default nrows and ncols are 1, using subplots() method.Create a colorbar for a ScalarMappable instance, *mappable*, using colorbar() method.Using plt.show(), we can show the figure.Exampleimport numpy as np import matplotlib.pyplot as plt import matplotlib.colors as colors N = 100 X, Y = np.mgrid[-3:3:complex(0, N), -2:2:complex(0, N)] Z1 = np.exp(-(X)**2 - ... Read More

How to plot ROC curve in Python?

Rishikesh Kumar Rishi
Updated on 16-Mar-2021 10:11:36

6K+ Views

ROC − Receiver operating characteristics (ROC) curve.Using metrics.plot_roc_curve(clf, X_test, y_test) method, we can draw the ROC curve.StepsGenerate a random n-class classification problem. This initially creates clusters of points normally distributed (std=1) about vertices of an ``n_informative``-dimensional hypercube with sides of length ``2*class_sep`` and assigns an equal number of clusters to each class.It introduces interdependence between these features and adds various types of further noise to the data. Use the make_classification() method.Split arrays or matrices into random trains, using train_test_split() method.Fit the SVM model according to the given training data, using fit() method.Plot Receiver operating characteristic (ROC) curve, using plot_roc_curve() method.To ... Read More

Automatically run %matplotlib inline in IPython Notebook

Rishikesh Kumar Rishi
Updated on 16-Mar-2021 20:15:30

212 Views

%matplotlib would return the backend value.%matplotlib auto would return the name of the backend, over Ipython shell.ExampleIn [1]: %matplotlib autoOutputUsing matplotlib backend: GTK3Agg

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