The 'yaltlogscale' property

Boolean Scalar

Valid for: Chart

If this property is set to 0 (which is the default), a normal linear scale applies for the alternate Y axis. If set to 1, a logarithmic scale is used for the alternate Y axis.

Note: You cannot set a logarithmic scale for an axis where any data point (or intercept) is 0 or negative. If this situation occurs, the scale will revert to linear.