The IDL procedure <tt>equa</tt>

Next: The IDL procedure Up: 3D Redshift Space Visualization Previous: The IDL procedure

# The IDL procedure equa

```pro equa, file_out, z_high

; Bo Milvang-Jensen, May 21, 1994.

if n_params() eq (0) then begin
print
print, 'Procedure equa'
print
print, 'Usage:'
print, 'equa, file_out, z_high'
print
print, 'Description:'
print, 'This procedure makes a binary file suitable for the Explorer'
print, 'module Line2Geo showing the equator'
print
print, 'file_out: output file name'
print, 'z_high  : maximum redshift (i.e. radius)'
print
return
end

a_low  =   0.0
a_high = 360.0
d_low  =   0.0
d_high =   0.0

arcl = 6.0

nde = fix((a_high-a_low)/arcl)

de = fltarr(2*(2+nde),3) ; arcs with delta = constant

for i=0, nde+1 do begin  ; delta = d_low
de(i,0) = z_high
de(i,1) = a_low + (1.0*i/(nde+1)) * (a_high-a_low)
de(i,2) = d_low
endfor

for i=0, nde+1 do begin  ; delta = d_high
de(i+nde+2,0) = z_high
de(i+nde+2,1) = a_low + (1.0*i/(nde+1)) * (a_high-a_low)
de(i+nde+2,2) = d_high
endfor

de(*,1) = (de(*,1)/180)*!pi ; conversion to radians
de(*,2) = (de(*,2)/180)*!pi ; conversion to radians

de = new_pol_to_cart(de) ; convert to cartesian coordiantes

openw, lun, file_out, /get_lun

for i=0, 1 do begin
writeu, lun, 1L*(nde+2)
for j=0, nde+1 do begin
writeu, lun, de(i*(nde+2)+j,*)
endfor
writeu, lun, 0.50     ; R
writeu, lun, 0.50     ; G
writeu, lun, 0.50     ; B
endfor

writeu, lun, -1L
close, lun
free_lun, lun

end```

Bo Milvang-Jensen
Wed Jan 18 05:44:35 MET 1995