Hello, you used: algebraic=true Do not do this: \psplot[linecolor=blue*,algebraic,*arrows=<->,arrowscale=1.5]{-7.5} regards Marco -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://tug.org/pipermail/pstricks/attachments/20090627/0f8f27b4/attachment.html>