Index: trunk/psastro/src/psastro.h
===================================================================
--- trunk/psastro/src/psastro.h	(revision 9574)
+++ trunk/psastro/src/psastro.h	(revision 9587)
@@ -20,4 +20,13 @@
 # define toTPA toTangentPlane
 # define toSky projection
+
+// this structure represents a fit to the logN / logS curve for a set of stars
+// logN = offset + slope * logS 
+typedef struct {
+  double mMin;
+  double mMax;
+  double offset;
+  double slope;
+} pmLumFunc;
 
 pmConfig         *psastroArguments (int argc, char **argv);