Transformation of normalized divergence and rotation into norm and angle ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Input: @1,@2...Divergence and rotation normalized so as to locally preserve maximum amplitudes during the propagation. SAMP... SEP parameter to amplify the rotation before further processing. Output: @3... Angle in radians, measured from divergence towards the rotation. @4... Norm, i.e. SQRT(div**2+(rot*SAMP)**2) Commands for grdcal.for ~~~~~~~~~~~~~~~~~~~~~~~ div=@1 rot=@2*SAMP div2=div*div rot2=rot*rot norm2=div2+rot2 absdiv=ABS(div) absdiv=AMAX1(absdiv,0.000001) div=SIGN(absdiv,div) @3=ATAN2(rot,div) @4=SQRT(norm2)