Area chart with plt.fill_between in Matplotlib - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the plt.fill_between function do in matplotlib?

It fills the area between two horizontal curves or between a curve and a baseline, creating an area chart.

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Which parameters are essential for plt.fill_between to create an area chart?

The x values, the y1 values (top curve), and optionally y2 values (bottom curve or baseline).

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How can you change the color and transparency of the filled area in plt.fill_between?

Use the color parameter to set the fill color and alpha to adjust transparency (0 to 1).

beginner

Why might you use an area chart instead of a line chart?

Area charts emphasize the magnitude of values over time or categories by filling the space under the line, making it easier to see volume or totals.

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What happens if you only provide one y array to plt.fill_between?

It fills the area between the y values and the x-axis (baseline at y=0).

What is the default baseline when using plt.fill_between(x, y)?

A y = min(y)

B y = 1

C No baseline, it fills between y and y

D y = 0 (x-axis)

If only one y array is given, the area is filled between y and the x-axis (y=0).

Which parameter controls the transparency of the filled area in plt.fill_between?

A alpha

B color

C linewidth

D linestyle

The alpha parameter sets transparency, where 0 is fully transparent and 1 is fully opaque.

What type of chart does plt.fill_between help create?

A Bar chart

B Scatter plot

C Area chart

D Pie chart

plt.fill_between fills the area under a curve, making an area chart.

If you want to fill between two curves y1 and y2, how do you call plt.fill_between?

A plt.fill_between(x, y1)

B plt.fill_between(x, y1, y2)

C plt.fill_between(y1, y2)

D plt.fill_between(y1)

You provide x, y1 (top curve), and y2 (bottom curve) to fill the area between them.

Which of these is NOT a valid use of plt.fill_between?

A Creating a scatter plot

B Filling area between two lines

C Highlighting ranges on x-axis

D Filling area under a line

plt.fill_between is not used for scatter plots; it fills areas between curves.

Explain how to create a simple area chart using plt.fill_between with example data.

Think about how you fill the area under a line using x and y arrays.

Describe the difference between a line chart and an area chart created with plt.fill_between.

Consider what the filled area adds visually compared to just a line.