ContourPlot doesn't work properly?

*To*: mathgroup at smc.vnet.net*Subject*: [mg23829] ContourPlot doesn't work properly?*From*: "Higinio Ramos Calle" <higra at gugu.usal.es>*Date*: Sat, 10 Jun 2000 03:00:51 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Let's take a common function like y=Exp[x] If I try to make a picture of this function in an implicit way with ContourPlot in the form ContourPlot[Log[y]-x,{x,-10,10},{y,-10,10}, PlotPoints->30,Contours->{0},ContourShading->False] with the option PlotPoints->30 in order to have a more precise picture I obtain an error message: ContourGraphics::ctpnt: The contour is attempting to traverse a cell in which some of the points have not evaluated to numbers, and it will be dropped. and no picture. But if I let the option PlotPoints his default value the message is the same, but now the picture is drawn. Could anyone explain what happens? higra at gugu.usal.es