git-svn-id: svn://svn.oetiker.ch/rrdtool/branches/1.2/program@1041
a5681a0c-68f1-0310-ab6d-
d61299d08faa
double new_range = factor * (im->maxval - im->minval);
double gridstep = im->ygrid_scale.gridstep;
double minor_y, minor_y_px, minor_y_px_frac;
double new_range = factor * (im->maxval - im->minval);
double gridstep = im->ygrid_scale.gridstep;
double minor_y, minor_y_px, minor_y_px_frac;
- im->maxval = im->minval + new_range;
+ if (im->maxval > 0.0)
+ im->maxval = im->minval + new_range;
+ else
+ im->minval = im->maxval - new_range;
ytr(im,DNAN); /* reset precalc */
/* make sure first minor gridline is on integer pixel y coord */
minor_y = gridstep * floor(im->minval / gridstep);
ytr(im,DNAN); /* reset precalc */
/* make sure first minor gridline is on integer pixel y coord */
minor_y = gridstep * floor(im->minval / gridstep);