400 setwidth
-1.2 7.15 setxrange
-1.2 7.1 setyrange
pictpointsOff

/xscale {
   ln 
} def
/yscale {
   ln 
} def

.1 1000 setyrange
.1 1000 setxrange
%% le quadrillage
gsave
   .4 setgray
   .4 setlinewidth
   [-1 3 log_seq] 
   dup {svrule} apply
   {shrule} apply
grestore

1 1 setorigine
[1 10 100 1000 10000] {xmark} apply
[1 10 100 1000 10000] {ymark} apply

{} courbe
bleu
10 10 9 cercle