XYGraph__SetPlotType (ul_pbar_graphics)

 *  Synopsis:
 *    #include <ul_pbar_graphics:xygraph.h>
 *
 *    TXYGraph__Result XYGraph__SetPlotType( int type )
 *
 *  Function intent:
 *    XYGraph__SetPlotType() allows the user to set the type of X-Y graph
 *    displayed by XYGraph__DisplayGraph().  The routine allows selection
 *    between linear, log base ten and log base e for both X and Y axes.
 *  Function parameters:
 *    type	graph type code(s) values may be ored together as required:
 *                WN_SCALE_LINEAR_BOTH
 *                WN_X_SCALE_LINEAR
 *                WN_X_SCALE_LOG10
 *                WN_X_SCALE_NATURAL_LOG
 *                WN_Y_SCALE_LINEAR
 *                WN_Y_SCALE_LOG10
 *                WN_Y_SCALE_NATURAL_LOG
 *  Function return value:
 *    CBS_OK	success
 *    ~CBS_OK	XYGraph__DisplayGraph() already called