Plot Data into Imshow with Custom Colormap in Matplotlib

Rishikesh Kumar Rishi
Updated on 15-May-2021 12:29:55

3K+ Views

To plot data into imshow() with custom colormap in matplotlib, we can take the following steps−Set the figure size and adjust the padding between and around the subplots.Create random data points using numpy.Generate a colormap object from a list of colors.Display the data as an image, i.e., on a 2D regular rasterTo display the figure, use show() method.Examplefrom matplotlib import pyplot as plt from matplotlib.colors import ListedColormap import numpy as np plt.rcParams["figure.figsize"] = [7.50, 3.50] plt.rcParams["figure.autolayout"] = True data = np.random.rand(5, 5) cmap = ListedColormap(['r', 'g', 'b']) plt.imshow(data, cmap=cmap) plt.show()OutputRead More

Turn Off Error Bars in Seaborn Bar Plot Using Matplotlib

Rishikesh Kumar Rishi
Updated on 15-May-2021 12:29:29

888 Views

To turn off error bars in a Seaborn bar plot, we can take the following steps−Load an example dataset from the online repository (requires Internet).Show the point estimates and confidence intervals with bars.To display the figure, use show() method.Exampleimport seaborn as sns import matplotlib.pyplot as plt plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True df = sns.load_dataset('titanic') sns.barplot(x='class', y='age', hue='survived', data=df, ci=None) plt.show()Output

Set Step on X-Axis in Matplotlib Figure

Rishikesh Kumar Rishi
Updated on 15-May-2021 12:24:35

2K+ Views

To set Step on X-axis in a figure in Matplotlib Python, we can take the following Steps −StepsCreate a list of data points, x.Add a subplot to the current figure using subplot() method.Set xticks and ticklabels with rotation=45.To display the figure, use show() method.Exampleimport matplotlib.pyplot as plt plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True x = [1, 2, 3, 4] y = [1.2, 1.9, 3.1, 4.2] plt.plot(x,y) ax1 = plt.subplot() ax1.set_xticks(x) ax1.set_xticklabels(["one", "two", "three", "four"], rotation=45) plt.show()Output

Read Image in Python using OpenCV

Rishikesh Kumar Rishi
Updated on 15-May-2021 12:24:17

997 Views

To read an image in Python OpenCV, we can take the following Steps −Load an image from a file.Display the image in the specified window.Wait for a pressed key.Destroy all of the HighGUI windows.Exampleimport cv2 img = cv2.imread("baseball.png", cv2.IMREAD_COLOR) cv2.imshow("baseball", img) cv2.waitKey(0) cv2.destroyAllWindows()Output

Get Default Blue Colour of Matplotlib Pyplot Scatter

Rishikesh Kumar Rishi
Updated on 15-May-2021 12:23:40

5K+ Views

The default color of a scatter point is blue. To get the default blue color of matplotlib scatter point, we can annotate them using annotate() method.StepsCreate a figure and a set of subplots using subplots() method.Plot a scatter point at (-1, 1) location.Add some label for that point.Plot a scatter point at (-0.9, 1) location.Add some label for that point.Plot a scatter point at (1.9, 1) location.Add some label for that point.Scale the x and y axes using xlim and ylim method.To display the figure, use show() method.Examplefrom matplotlib import pyplot as plt plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True ... Read More

Set Same Color for Markers and Lines in Matplotlib Plot Loop

Rishikesh Kumar Rishi
Updated on 15-May-2021 12:23:17

1K+ Views

To set the same color for markers and lines in a matplotlib, we can take the following Steps −Initialize m, n and x data points using numpy.Create a new figure or activate an existing figure using figure() method.Clear the figure using clf() method.Add a subplot to the current figure using subplot() method.Get a marker from a iterable marker type.Iterate a range from 1 to n.Plot the lines and markers in the loop using plot() method with the same marker and colors for a line.To display the figure, use show() method.Exampleimport numpy as np import itertools from matplotlib import pyplot as ... Read More

Plot a Rectangle with Edgecolor in Matplotlib

Rishikesh Kumar Rishi
Updated on 15-May-2021 12:22:52

2K+ Views

To put edgecolor of a rectangle in matplotlib, we can take the following Steps −Create a new figure or activate an existing figure using figure() method.Add a subplot method to the current axis.Create a rectangle instance using Rectangle() class with an edgecolor and linewidth of the edge.Add a rectangle path on the plot.To place the text in the rectangle, we can use text() method.Scale x and y axes using xlim() and ylim() methods.To display the figure, use show() method.Exampleimport matplotlib from matplotlib import pyplot as plt, patches plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True fig = plt.figure() ax = fig.add_subplot(111) ... Read More

Center X-Tick Labels Between Tick Marks in Matplotlib

Rishikesh Kumar Rishi
Updated on 15-May-2021 12:17:52

977 Views

To place labels between two ticks, we can take the following steps−Load some sample data, r.Create a copy of the array, cast to a specified type.Create a figure and a set of subplots using subplots() method.Plot date and r sample data.Set the locator of the major/minor ticker using set_major_locator() and set_minor_locator() methods.Set the locator of the major/minor formatter using set_major_locator() and set_minor_formatter() methods.Now, place the ticklabel at the center.To display the figure, use show() method.Exampleimport numpy as np import matplotlib.cbook as cbook import matplotlib.dates as dates import matplotlib.ticker as ticker import matplotlib.pyplot as plt plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = ... Read More

Change Table Font Size with Matplotlib Pyplot

Rishikesh Kumar Rishi
Updated on 15-May-2021 12:17:24

8K+ Views

To change a table's fontsize with matplotlib, we can use set_fontsize() method.StepsCreate a figure and a set of subplots, nrows=1 and ncols=1.Create random data using numpy.Create columns value.Make the axis tight and off.Initialize a variable fontsize to change the font size.Set the font size of the table using set_font_size() method.To display the figure, use show() method.Exampleimport numpy as np from matplotlib import pyplot as plt plt.rcParams["figure.figsize"] = [7.00, 3.50] plt.rcParams["figure.autolayout"] = True fig, axs = plt.subplots(1, 1) data = np.random.random((10, 3)) columns = ("Column I", "Column II", "Column III") axs.axis('tight') axs.axis('off') the_table = axs.table(cellText=data, colLabels=columns, loc='center') the_table.auto_set_font_size(False) the_table.set_fontsize(10) plt.show()OutputRead More

Changing Matplotlib Subplot Size and Position After Axes Creation

Rishikesh Kumar Rishi
Updated on 15-May-2021 12:16:58

1K+ Views

To change subplot size or position after axes creation, we can take the following steps−Create a new figure or activate an existing figure using figure() method.Add an '~.axes.Axes' to the figure as part of a subplot arrangement using add_subplot() method.A grid layout to place subplots within a figure using GridSpec() class.Set the position of the grid specs.Set the subplotspec instance.Add an '~.axes.Axes' to the figure as part of a subplot arrangement using add_subplot() method, with gridspec instance.Adjust the padding between and around the subplots.To display the figure, use show() method.Examplefrom matplotlib import pyplot as plt from matplotlib import gridspec as ... Read More

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