-.5 4 setxrange
-.5 4 setyrange

/M0 {1.75 2} def
M0 1 0 translatepoint /M' defpoint
M0 2 0 translatepoint /M" defpoint

traceaxes
unites
axesarrow

[M0 M" M0 45 rotatepoint] ligne
M" M0 M" M0 45 rotatepoint .5 (<-) tripointarcarrow 
[M0 M" M0 -60 rotatepoint] ligne
M" M0 -60 rotatepoint M0 M" .7 (->) tripointarcarrow 

medium setcourbelinewidth
[1 0 O 0 1] ligne

/arrowscale {.7 dup} def
M0 M' tracevecteur
M0 M' M0 45 rotatepoint tracevecteur
M0 M' M0 -60 rotatepoint tracevecteur
M0 times2