scaxis.cwp.lib

su 的源代码库

SCAXIS - compute a readable scale for use in plotting axes

scaxis		compute a readable scale for use in plotting axes

Function Prototype:
void scaxis (float x1, float x2, int *nxnum, float *dxnum, float *fxnum);

Input:
x1		first x value
x2		second x value
nxnum		desired number of numbered values

Output:
nxnum		number of numbered values
dxnum		increment between numbered values (dxnum>0.0)
fxnum		first numbered value

Notes:
scaxis attempts to honor the user-specified nxnum.  However, nxnum
will be modified if necessary for readability.  Also, fxnum and nxnum
will be adjusted to compensate for roundoff error; in particular, 
fxnum will not be less than xmin-eps, and fxnum+(nxnum-1)*dxnum 
will not be greater than xmax+eps, where eps = 0.0001*(xmax-xmin).
xmin is the minimum of x1 and x2.  xmax is the maximum of x1 and x2.

Author:  Dave Hale, Colorado School of Mines, 01/13/89