iOS Charting Documentation - SciChart iOS Charts SDK v3.x

Axis APIs - Value Axis vs. Category Axis

SciChart 2D iOS Features several axis types which could be Value or Category. All inherit from SCIAxisBase. So what’s the difference between Value and Category Axes? An explanation is given below.

Given the data:

Age (X-Axis) Cats Dogs Fish
1 7 7 8
9 6 5 7
10 5 4 3
20 4 3 2

A Value X-Axis and Category X-Axis would display the data differently:

Category X-Axis Value X-Axis
Default Flipped

The fundamental difference is a Value-Axis uses the X-Value to compute distance on the XAxis, whereas a Category-Axis uses the X-Index. Value-Axis are primarily used in scientific software where Category–Axis are typically used in financial software (e.g. stock charts).

SciChart features both Value-Axis and Category-Axis types.

Axis Type Value or Category Axis
SCINumericAxis Value Axis
SCILogarithmicNumericAxis Value Axis
SCIDateAxis Value Axis
SCICategoryDateAxis Category Axis

For more information, refer to the Axis APIs article.