Index: /branches/eam_branches/ohana.20190329/src/opihi/mana/deimos_fitslit.c
===================================================================
--- /branches/eam_branches/ohana.20190329/src/opihi/mana/deimos_fitslit.c	(revision 40769)
+++ /branches/eam_branches/ohana.20190329/src/opihi/mana/deimos_fitslit.c	(revision 40770)
@@ -51,4 +51,8 @@
     for (int ix = 0; ix < Nx; ix++) {
       
+      // skip NAN / Inf pixels in either window or slit
+      if (!isfinite(Fwind[ix + iy*Nx])) continue;
+      if (!isfinite(Fprof[ix + iy*Nx])) continue;
+
       float fxy = Fwind[ix + iy*Nx];
       float pxy = Fprof[ix + iy*Nx];