I would like to draw a curve in latex but when I put this code
\psset{algebraic=true} \pspicture(-2,-0.5)(2,2) \psline{<->}(-2,0)(2,0) \psline{->}(0,-0.5)(0,2) \psplot{-1.5}{1}{x*x+x} \endpspicture theses errors appear
! Undefined control sequence.<recently read> \c@lor@to@ps \psline( ! Undefined control sequence.\XC@usec@lor ...string \color@ #1#2\endcsname \@@\fi \space \psline( ! Undefined control sequence.<recently read> \c@lor@to@ps \psline Please if someone can help me because i didn't understand why this error appears.
\documentclass{article} \usepackage[french]{babel} \usepackage{color} \usepackage{xcolor} %les couleurs \definecolor{myblue}{rgb}{0.2,0.4,1} \usepackage{layout} \usepackage[top=2 cm, bottom=2 cm, left=2 cm, right=2 cm]{geometry} \usepackage{setspace} \usepackage{graphicx} \usepackage{array} \usepackage{pstricks-add} \usepackage{pst-eucl} \begin{document} \psset{algebraic=true} \pspicture(-2,-0.5)(2,2) \psline{<->}(-2,0)(2,0) \psline{->}(0,-0.5)(0,2) \psplot{-1.5}{1}{x*x+x} \endpspicture \end{document} 


