Set the input dataset to the mapper. The format needs to change depending on what you're trying to print. See also the ivar LabeledComponent which can be used to specify the component to print if you want to only print one of several. If the data has more than one component, use the method SetLabeledComponent to control which components to plot. However, if this ivar is nonnegative, then only the one component specified is labeled.
Shadows make the text easier to read.