XmScaleSetTicks man page
XmScaleSetTicks — A Scale function that controls tick marks
#include <Xm/Scale.h> void XmScaleSetTicks( Widget scale, int big_every, Cardinal num_medium, Cardinal num_small, Dimension size_big, Dimension size_medium, Dimension size_small);
XmScaleSetTicks controls the number, location, and size of the tick marks on a Scale. Each tick mark is a SeparatorGadget oriented perpendicular to the Scale's orientation. For example, if the Scale is oriented horizontally, the tick marks will be oriented vertically.
If you specify tick marks for a Scale and then change the Scale's orientation, you will have to do the following:
Remove all the tick marks. To remove tick marks from a Scale, you must destroy (with XtDestroyChildren) the SeparatorGadget tick marks. The first two children of a Scale are its title and scroll bar, and all additional children are tick marks.
Recreate the tick marks by calling XmScaleSetTicks.
Specifies the Scale widget ID that is getting the tick marks.
Specifies the number of scale values between big ticks.
Specifies the number of medium ticks between big values.
Specifies the number of small ticks between medium values.
Specifies the size (either width or height) of the big ticks.
Specifies the size (either width or height) of the medium ticks.
Specifies the size (either width or height) of the small ticks.
For a complete definition of Scale and its associated resources, see XmScale(3).