Index: /branches/eam_branches/ipp-20140904/Ohana/src/fakeastro/doc/example.sh
===================================================================
--- /branches/eam_branches/ipp-20140904/Ohana/src/fakeastro/doc/example.sh	(revision 37483)
+++ /branches/eam_branches/ipp-20140904/Ohana/src/fakeastro/doc/example.sh	(revision 37484)
@@ -28,2 +28,53 @@
 end
 
+macro check.proper.motion
+
+  # create a bunch of test stars:
+  create n 0 10000
+  set L = 360.0*rnd(n)
+  set B = dasin(2.0*rnd(n) - 1.0)
+
+  # choose a hardwired proper motion
+  set uL = 1.0*(rnd(n) - 0.5)
+  set uB = 1.0*(rnd(n) - 0.5)
+
+  set Bo = B + uB/3600.0
+  set Lo = L + uL/3600.0/dcos(B)
+
+  set R = L
+  set D = B
+  set Ro = Lo
+  set Do = Bo
+
+  csystem G C R D
+  csystem G C Ro Do
+
+  set uR1 = (Ro - R)*3600.0*dcos(D)
+  set uD1 = (Do - D)*3600.0
+
+  $Xo  = 282.8594812080
+  $xo  =  32.9319185700
+  $phi = -62.8717488056
+
+  $delta_G = 90 + $phi
+  $alpha_G = $Xo - 90
+
+  # I got this wrong:
+  # set C1 = dcos(D)*dcos($phi) + dsin(D)*dcos(R)*dsin($phi)*dsin($Xo) + dsin(D)*dsin(R)*dsin($phi)*dcos($Xo)
+  # set C2 =                              dcos(R)*dsin($phi)*dcos($Xo) +         dsin(R)*dsin($phi)*dsin($Xo)
+
+  # corrected version
+    set C1 = dcos(D)*dcos($phi) + dsin(D)*dcos(R)*dsin($phi)*dsin($Xo) - dsin(D)*dsin(R)*dsin($phi)*dcos($Xo)
+    set C2 =                           -1*dcos(R)*dsin($phi)*dcos($Xo) -         dsin(R)*dsin($phi)*dsin($Xo)
+
+  # set C1 = dcos(D)*dsin($delta_G) - dsin(D)*dcos($delta_G)*dcos(R - $alpha_G)
+  # set C2 =                                  dcos($delta_G)*dsin(R - $alpha_G)
+
+  set cB = 1.0 / sqrt(C1^2 + C2^2)
+
+  set uR2 = cB * (C1 * uL - C2 * uB)
+  set uD2 = cB * (C1 * uB + C2 * uL)
+
+  set duR = uR1 - uR2
+  set duD = uD1 - uD2
+end