How to visualize graph with different data types: boolean & integer?

Question

I have two variables:

• A is an integer from 0-1000u (u=some arbitrary unit)
• B is either 1 or 0

I need to visualize a graph (or graphs) to show the relationship of A & B (y-axis) against t (time; x-axis) and also relationship between A & B

I tried showing them on one graph, but having Boolean and integer value on the same y-axis looks incorrect.

I could just do 2 separate graphs: A/t & B/t but I'm wondering if there's a more elegant way of visualizing this which also shows the relationship between A & B more clearly.

Answer 1

You might get better answer at Cross Validated SE but I'd use a graph with two y-axis. One axis with values from 0 to 1000 and the other with values 0 to 1. Having values from 0 to 1000 shown as line and values from 0 to 1 as bars results in the following graph. Presenting the boolean value as stepped line might be more suitable though.

Answer 2

I recommend the binary variable to be represented by background color (see mockup below). This way, it would provide context, or tight spatial relationship, with the numeric variable line over it.