about north polar projection

[Stergios Misios]

Hello all,
I am plotting a vector plot in North polar projection from 20 N to 87.5
N. I want my graph to be round, and for this i use,
set annot 1
With this command i skip the black square box but i lose also the arrow
labeling. How can i make it visible?
I want also to have a black circle to define the edge of my plot.
What can i do in order to define that i don;t want to print vectors
between specific  values? I have tried
set black -5 5
but still the vector heads are printed,
Thank you,
Stergios

(my  script)
-----------------------------------------
'reinit'
'open 'infile''
'set grads off'
'set t 12'
'set lev 'level''
'set lon -180 180'
'set lat 20 87.5'
*
'set mproj nps'
'set map 1'
'set annot 0'
*
'set gxout vector'
'set arrscl 0.4 15'
'set arrowhead 0.03'
'set black -5 5'
*
'd skip(1/sqrt('level'/1000)*epx,2,2);1/sqrt('level'/1000)*epy'
'set annot 1'
'draw title .......'