xbasc();/// @@prerequisite 
v=rand(1,2000,'n');
histplot([-6:0.4:6],v,[1],'015',' ',[-4,0,4,0.5],[2,2,2,1]);/// \sleftarrow{\normalfont a  histogram } \index{histplot@\texttt{histplot}}
function [y]=f2(x); y=exp(-x.*x/2)/sqrt(2*%pi); endfunction;
x=-6:0.1:6;x=x';plot2d(x,f2(x),1);  /// \sleftarrow{\normalfont superimposing an  \( \R\sp{2}\) curve (Figure~\ref{f:gr4}) }
xs2ps(0,'fig4');/// @@prerequisite affectations 
unix(SCI+'/bin/BEpsf fig4'); /// @@prerequisite