Skip to main content

Size

In a scatter plot, you can encode a third variable by mapping it to the size of the points. This is sometimes called a bubble chart and is effective for displaying three numeric dimensions simultaneously.

Scatter plot with point size proportional to a numeric variable

How to add size​

To map a variable to point size, select a numeric variable from the Size by dropdown in the Add to Plot panel.

How it works​

  • Point sizes are scaled proportionally to the values of the selected variable
  • Larger values produce larger points; smaller values produce smaller points
  • Missing values in the size variable are shown as small cross symbols to indicate they are present in the data but lack a size value
  • A legend shows the mapping from values to point sizes

Resize methods​

iNZight provides two methods for sizing points:

  • Proportional (default): Point sizes are directly proportional to the variable values. This gives an intuitive mapping where the visual size reflects the data value.
  • Emphasize: An alternative method that can make differences in size more prominent.

Tips for use​

  • Size works best when the numeric variable has a meaningful range — if all values are similar, the size differences will be hard to see
  • Combining size with colour allows you to display up to four variables at once (x, y, colour, size)
  • Be mindful that large points can overlap and obscure smaller points. Adjusting transparency can help

Applicable plot types​

Size mapping is available for scatter plots only.