Dual-axis chart
Shows the mean of one variable as bars (left axis) and of another as a line (right axis) across the same categories.
Menu: Graphs → More charts → Dual-axis chart…
When should I use it?
- Showing two related measures in different units.
What are the assumptions?
- Two numeric variables summarized by the same categories.
How do I run it in StatLab?
- Choose the category axis and the two variables.
How do I read the output?
| Output | Meaning |
|---|---|
| Bars and line | Read each against its own axis (labelled). |
Worked example
On the practice survey dataset (File → Sample dataset), this command — which the dialog's Paste button also produces — runs the procedure:
PROC vizDual /x=group /y=score /y2=age.
Computed by StatLab's validated procedure code when this page was built. The example only illustrates the steps; choose variables that fit your own research question.
What are common mistakes?
- Implying a relationship from where the two series cross — the crossing depends on the axis scales.