Try replacing [nticks,50] with [grid, 100, 100]). --Barton -----maxima-bounces at math.utexas.edu wrote: ----- >contour_plot?(f(x,y),?[x,?-4,?4],?[y,?-4,?4],[adapt_depth,?10],[nticks,50])$ >But?the?result?is?not?good. Can?I?do?it?better??