;
; batch.pro converted to a programme
; execute it as
; IDL> .r batch2
;
; +++++++++++++++++++++++++++++++++++++++++
;    a simple contour plot of a Gaussian  +
; +++++++++++++++++++++++++++++++++++++++++
x    = -nsig + findgen(npts)/float(npts)*2*nsig
Gs   = fltarr(npts,npts)
for j=0,npts-1 do begin 
    for i=0,npts-1 do begin 
        Gs[i,j] = exp(-(x[i]^2+x[j]^2)/2.)
    endfor 
endfor

contour,Gs,x,x,nlev=255,/iso,/fill

end