Time series with fill_between in Matplotlib - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the fill_between function do in matplotlib?

It fills the area between two curves or between a curve and a baseline, often used to highlight ranges or confidence intervals in time series plots.

beginner

How do you specify the x-axis values in fill_between?

You pass the x-axis values as the first argument, which defines the horizontal positions where the area will be filled.

intermediate

Why is fill_between useful in time series analysis?

It visually highlights ranges such as confidence intervals, thresholds, or differences between two time series, making trends and uncertainty easier to understand.

beginner

What parameters can you use to customize the appearance of the filled area in fill_between?

You can use parameters like color, alpha (transparency), and label to control the fill color, transparency, and legend entry.

beginner

Can fill_between fill between a curve and a constant baseline?

Yes, you can fill between a curve and a constant value by passing the constant as the second y-value argument.

What is the main purpose of fill_between in matplotlib?

A To fill the area between two lines or a line and a baseline

B To plot scatter points on a graph

C To create bar charts

D To add text annotations

fill_between fills the area between two curves or between a curve and a baseline, useful for highlighting ranges.

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

A color

B alpha

C linewidth

D linestyle

The alpha parameter sets the transparency level of the fill color.

If you want to fill between a time series and zero, how would you use fill_between?

A Only pass the series as y

B Fill between two series only

C Use <code>plot</code> instead

D Pass the time values as x, the series as y1, and zero as y2

You pass the x values, the series as the first y, and zero as the second y to fill between the series and zero.

Which of these is NOT a typical use of fill_between in time series plots?

A Highlighting confidence intervals

B Showing thresholds or limits

C Plotting individual data points

D Comparing two time series visually

fill_between is for filling areas, not plotting individual points.

What happens if you omit the second y argument in fill_between?

A It fills between the first y and zero by default

B It causes an error

C It fills between the first y and the x-axis values

D It fills between two identical curves

If the second y is omitted, fill_between fills between the first y and zero.

Explain how you would use fill_between to highlight a confidence interval around a time series.

Think about passing x, lower bound, and upper bound arrays to fill_between.

Describe the benefits of using fill_between in time series visualization compared to just plotting lines.

Consider how shaded areas help viewers see important ranges or differences.