Heatmap with plt.pcolormesh in Matplotlib - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does plt.pcolormesh do in matplotlib?

It creates a heatmap by coloring a grid of cells based on the values in a 2D array. Each cell's color represents the data value at that position.

beginner

What type of data structure is typically used as input for plt.pcolormesh?

A 2D array or matrix of numerical values, where each value corresponds to the color intensity of a cell in the heatmap.

beginner

How can you add a color bar to a heatmap created with plt.pcolormesh?

Use plt.colorbar() after calling plt.pcolormesh to show a color scale that explains the mapping of colors to data values.

intermediate

What is the difference between plt.pcolormesh and plt.imshow for heatmaps?

plt.pcolormesh uses a grid of colored cells and can handle non-uniform grids, while plt.imshow displays an image from an array and is simpler but less flexible for irregular grids.

beginner

How do you control the color map used in plt.pcolormesh?

You can pass the cmap parameter with a colormap name like 'viridis', 'plasma', or 'coolwarm' to change the colors of the heatmap.

What input does plt.pcolormesh require to create a heatmap?

A A 2D array of numerical values

B A list of strings

C A single number

D A 1D array of numbers

plt.pcolormesh needs a 2D array to map each value to a colored cell in the heatmap.

Which function adds a color scale bar to a heatmap made with plt.pcolormesh?

A plt.grid()

B plt.legend()

C plt.title()

D plt.colorbar()

plt.colorbar() adds a color bar that shows how colors map to data values.

What parameter changes the color scheme in plt.pcolormesh?

A color

B cmap

C style

D palette

The cmap parameter sets the colormap for the heatmap colors.

Which is true about plt.pcolormesh compared to plt.imshow?

A <code>plt.pcolormesh</code> can handle irregular grids

B <code>plt.imshow</code> can handle irregular grids

C Both handle irregular grids equally

D Neither can handle irregular grids

plt.pcolormesh is more flexible for non-uniform grid data.

What does each colored cell in a plt.pcolormesh heatmap represent?

A A category label

B A date or time

C A numerical value from the data

D A text string

Each cell's color corresponds to a numerical value in the 2D data array.

Explain how to create a heatmap using plt.pcolormesh from a 2D data array.

Think about the steps from data to visual colors.

Describe the advantages of using plt.pcolormesh over plt.imshow for heatmaps.

Consider flexibility with grid shapes.