Index: /trunk/psModules/src/objects/models/fwhm.sh
===================================================================
--- /trunk/psModules/src/objects/models/fwhm.sh	(revision 36857)
+++ /trunk/psModules/src/objects/models/fwhm.sh	(revision 36857)
@@ -0,0 +1,218 @@
+
+macro find.fwhm.pgauss
+  if ($0 != 1)
+    echo "USAGE: find.fwhm"
+    break
+  end
+  
+  $dz = 0.01
+  create z 0 50 $dz
+
+  # Gaussian taylor expansion
+  # f = 1 / (1 + z + z^2/2 + z^3/6)
+  # 1 + z + z^2/2 + z^3/6 = 2
+  # f = z + z^2/2 + z^3/6 - 2, find where f == 0.0
+  
+  set f = z + 0.5*z^2 + (1/6.0)*z^3 - 2.0
+  set dfdz = 1 + z + 0.5*z^2
+
+  lim -n 0 z f; clear; box; plot z f
+  lim -n 1 z dfdz; clear; box; plot z dfdz  
+
+  $nZ0 = 0
+  $nZ1 = 5 / $dz
+
+  $Zg = 0.5*(z[$nZ0] + z[$nZ1])  
+  $nZg = int($Zg / $dz)
+  $dZ = 1.0
+
+  for i 0 10
+    $Fg = f[$nZg]
+    $dFdz_g = dfdz[$nZg]
+
+    $dZ = $Fg / $dFdz_g
+
+    echo $Zg $Fg $dZ $dFdz_g
+
+    $Zg -= $dZ
+    $Zg = max ($Zg , 0)
+    $nZg = int($Zg / $dz)
+  end 
+  echo $Zg $Fg $dZ $dFdz_g
+  $Zhm = $Zg
+  $FWHM = 2*sqrt(2*$Zg)
+
+  echo $Zhm : $FWHM
+end
+
+macro find.fwhm.rgauss
+  if ($0 != 2)
+    echo "USAGE: find.fwhm (K)"
+    break
+  end
+  
+  $K = $1
+
+  if ($K == 0.0)
+    $Zhm = (sqrt(5) - 1.0) / 2.0
+    $FWHM = 2*sqrt(2*$Zhm)
+    echo $K : $Zhm : $FWHM
+    return
+  end
+
+  $dz = 0.01
+  create z 0 50 $dz
+
+  # set f = 1.0 / (1.0 + $K*z + z^1.667)
+  # f = $K*z + z^1.667 - 1.0, find where f == 0.0
+  
+  set f = z + z^$K - 1.0
+  set dfdz = ln(z) * z^$K + 1.0
+
+  lim -n 0 z f; clear; box; plot z f
+  lim -n 1 z dfdz; clear; box; plot z dfdz  
+
+  $nZ0 = 0
+  $nZ1 = 5 / $dz
+
+  $Zg = 0.5*(z[$nZ0] + z[$nZ1])  
+  $nZg = int($Zg / $dz)
+  $dZ = 1.0
+
+  for i 0 10
+    $Fg = f[$nZg]
+    $dFdz_g = dfdz[$nZg]
+
+    $dZ = $Fg / $dFdz_g
+
+    echo $nZg $Zg $Fg $dZ $dFdz_g
+
+    $Zg -= $dZ
+    $Zg = max ($Zg , 0)
+    $nZg = int($Zg / $dz)
+  end 
+  # echo $Zg $Fg $dZ $dFdz_g
+  $Zhm = $Zg
+  $FWHM = 2*sqrt(2*$Zg)
+
+  echo $K : $Zhm : $FWHM
+end
+
+macro find.fwhm.ps1v1
+  if ($0 != 2)
+    echo "USAGE: find.fwhm (K)"
+    break
+  end
+  
+  $K = $1
+
+  if ($K == 0.0)
+    $Zhm = 1.0
+    $FWHM = 2*sqrt(2)
+    echo $K : $Zhm : $FWHM
+    return
+  end
+
+  $dz = 0.01
+  create z 0 50 $dz
+
+  # set f = 1.0 / (1.0 + $K*z + z^1.667)
+  # f = $K*z + z^1.667 - 1.0, find where f == 0.0
+  
+  set f = $K*z + z^1.667 - 1.0
+  set dfdz = $K + z^0.667
+
+  #lim -n 0 z f; clear; box; plot z f
+  #lim -n 1 z dfdz; clear; box; plot z dfdz  
+
+  $nZ0 = 0
+  $nZ1 = 5 / $dz
+
+  $Zg = 0.5*(z[$nZ0] + z[$nZ1])  
+  $nZg = int($Zg / $dz)
+  $dZ = 1.0
+
+  for i 0 10
+    $Fg = f[$nZg]
+    $dFdz_g = dfdz[$nZg]
+
+    $dZ = $Fg / $dFdz_g
+
+    # echo $Zg $Fg $dZ $dFdz_g
+
+    $Zg -= $dZ
+    $Zg = max ($Zg , 0)
+    $nZg = int($Zg / $dz)
+  end 
+  # echo $Zg $Fg $dZ $dFdz_g
+  $Zhm = $Zg
+  $FWHM = 2*sqrt(2*$Zg)
+
+  echo $K : $Zhm : $FWHM
+end
+
+# qgauss is like ps1_v1 with z^2.25
+macro find.fwhm.qgauss
+  if ($0 != 2)
+    echo "USAGE: find.qgauss (K)"
+    break
+  end
+  
+  $K = $1
+
+  if ($K == 0.0)
+    $Zhm = 1.0
+    $FWHM = 2*sqrt(2)
+    echo $K : $Zhm : $FWHM
+    return
+  end
+
+  $dz = 0.01
+  create z 0 50 $dz
+
+  # set f = 1.0 / (1.0 + $K*z + z^2.25)
+  # f = $K*z + z^2.25 - 1.0, find where f == 0.0
+  
+  set f = $K*z + z^2.25 - 1.0
+  set dfdz = $K + z^1.25
+
+  #lim -n 0 z f; clear; box; plot z f
+  #lim -n 1 z dfdz; clear; box; plot z dfdz  
+
+  $nZ0 = 0
+  $nZ1 = 5 / $dz
+
+  $Zg = 0.5*(z[$nZ0] + z[$nZ1])  
+  $nZg = int($Zg / $dz)
+  $dZ = 1.0
+
+  for i 0 10
+    $Fg = f[$nZg]
+    $dFdz_g = dfdz[$nZg]
+
+    $dZ = $Fg / $dFdz_g
+
+    # echo $Zg $Fg $dZ $dFdz_g
+
+    $Zg -= $dZ
+    $Zg = max ($Zg , 0)
+    $nZg = int($Zg / $dz)
+  end 
+  # echo $Zg $Fg $dZ $dFdz_g
+  $Zhm = $Zg
+  $FWHM = 2*sqrt(2*$Zg)
+
+  echo $K : $Zhm : $FWHM
+end
+
+macro fwhm.trend
+
+  delete fwhm_v k_v
+
+  for k 0 20 1.0
+    find.fwhm.qgauss $k
+    concat $k k_v
+    concat $FWHM fwhm_v
+  end
+end
+
Index: /trunk/psModules/src/objects/models/pmModel_DEV.c
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_DEV.c	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_DEV.c	(revision 36857)
@@ -36,7 +36,7 @@
 #include "pmMoments.h"
 #include "pmModelFuncs.h"
+#include "pmModelClass.h"
 #include "pmModel.h"
 #include "pmModelUtils.h"
-#include "pmModelClass.h"
 #include "pmSourceMasks.h"
 #include "pmSourceExtendedPars.h"
@@ -59,4 +59,5 @@
 # define PM_MODEL_LIMITS          pmModelLimits_DEV
 # define PM_MODEL_RADIUS          pmModelRadius_DEV
+# define PM_MODEL_SET_FWHM        pmModelSetFWHM_DEV
 # define PM_MODEL_FROM_PSF        pmModelFromPSF_DEV
 # define PM_MODEL_PARAMS_FROM_PSF pmModelParamsFromPSF_DEV
@@ -336,4 +337,8 @@
 }
 
+psF64 PM_MODEL_SET_FWHM (const psVector *params, psF64 sigma) {
+  return (NAN);
+}
+
 bool PM_MODEL_FROM_PSF (pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf)
 {
@@ -357,5 +362,5 @@
     // the 2D PSF model fits polarization terms (E0,E1,E2)
     // convert to shape terms (SXX,SYY,SXY)
-    bool useReff = pmModelUseReff (modelPSF->type);
+    bool useReff = modelPSF->class->useReff;
     if (!pmPSF_FitToModel (out, 0.1, useReff)) {
         psTrace("psModules.objects", 5, "Failed to fit object at (r,c) = (%.1f,%.1f)", in[PM_PAR_YPOS], in[PM_PAR_XPOS]);
@@ -411,5 +416,5 @@
     // convert to shape terms (SXX,SYY,SXY)
     // XXX user-defined value for limit?
-    bool useReff = pmModelUseReff (model->type);
+    bool useReff = model->class->useReff;
     if (!pmPSF_FitToModel (PAR, 0.1, useReff)) {
         psTrace ("psModules.objects", 3, "Failed to fit object at (r,c) = (%.1f,%.1f)", Xo, Yo);
Index: /trunk/psModules/src/objects/models/pmModel_DEV.h
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_DEV.h	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_DEV.h	(revision 36857)
@@ -8,4 +8,5 @@
 psF64 pmModelFlux_DEV(const psVector *params);
 psF64 pmModelRadius_DEV(const psVector *params, psF64 flux);
+psF64 pmModelSetFWHM_DEV(const psVector *params, psF64 flux);
 bool pmModelFromPSF_DEV(pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf);
 bool  pmModelParamsFromPSF_DEV(pmModel *model, const pmPSF *psf, float Xo, float Yo, float Io);
Index: /trunk/psModules/src/objects/models/pmModel_EXP.c
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_EXP.c	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_EXP.c	(revision 36857)
@@ -33,7 +33,7 @@
 #include "pmMoments.h"
 #include "pmModelFuncs.h"
+#include "pmModelClass.h"
 #include "pmModel.h"
 #include "pmModelUtils.h"
-#include "pmModelClass.h"
 #include "pmSourceMasks.h"
 #include "pmSourceExtendedPars.h"
@@ -56,4 +56,5 @@
 # define PM_MODEL_LIMITS          pmModelLimits_EXP
 # define PM_MODEL_RADIUS          pmModelRadius_EXP
+# define PM_MODEL_SET_FWHM        pmModelSetFWHM_EXP
 # define PM_MODEL_FROM_PSF        pmModelFromPSF_EXP
 # define PM_MODEL_PARAMS_FROM_PSF pmModelParamsFromPSF_EXP
@@ -343,4 +344,8 @@
 }
 
+psF64 PM_MODEL_SET_FWHM (const psVector *params, psF64 sigma) {
+  return (NAN);
+}
+
 bool PM_MODEL_FROM_PSF (pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf)
 {
@@ -364,5 +369,5 @@
     // the 2D PSF model fits polarization terms (E0,E1,E2)
     // convert to shape terms (SXX,SYY,SXY)
-    bool useReff = pmModelUseReff (modelPSF->type);
+    bool useReff = modelPSF->class->useReff;
     if (!pmPSF_FitToModel (out, 0.1, useReff)) {
         psTrace("psModules.objects", 5, "Failed to fit object at (r,c) = (%.1f,%.1f)", in[PM_PAR_YPOS], in[PM_PAR_XPOS]);
@@ -418,5 +423,5 @@
     // convert to shape terms (SXX,SYY,SXY)
     // XXX user-defined value for limit?
-    bool useReff = pmModelUseReff (model->type);
+    bool useReff = model->class->useReff;
     if (!pmPSF_FitToModel (PAR, 0.1, useReff)) {
         psTrace ("psModules.objects", 3, "Failed to fit object at (r,c) = (%.1f,%.1f)", Xo, Yo);
Index: /trunk/psModules/src/objects/models/pmModel_EXP.h
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_EXP.h	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_EXP.h	(revision 36857)
@@ -8,4 +8,5 @@
 psF64 pmModelFlux_EXP(const psVector *params);
 psF64 pmModelRadius_EXP(const psVector *params, psF64 flux);
+psF64 pmModelSetFWHM_EXP(const psVector *params, psF64 flux);
 bool pmModelFromPSF_EXP(pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf);
 bool  pmModelParamsFromPSF_EXP(pmModel *model, const pmPSF *psf, float Xo, float Yo, float Io);
Index: /trunk/psModules/src/objects/models/pmModel_GAUSS.c
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_GAUSS.c	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_GAUSS.c	(revision 36857)
@@ -33,7 +33,7 @@
 #include "pmMoments.h"
 #include "pmModelFuncs.h"
+#include "pmModelClass.h"
 #include "pmModel.h"
 #include "pmModelUtils.h"
-#include "pmModelClass.h"
 #include "pmSourceMasks.h"
 #include "pmSourceExtendedPars.h"
@@ -54,4 +54,5 @@
 # define PM_MODEL_GUESS           pmModelGuess_GAUSS
 # define PM_MODEL_LIMITS          pmModelLimits_GAUSS
+# define PM_MODEL_SET_FWHM        pmModelSetFWHM_GAUSS
 # define PM_MODEL_RADIUS          pmModelRadius_GAUSS
 # define PM_MODEL_FROM_PSF        pmModelFromPSF_GAUSS
@@ -257,4 +258,8 @@
 }
 
+psF64 PM_MODEL_SET_FWHM (const psVector *params, psF64 sigma) {
+    return (2.35482004503*sigma);
+}
+
 // construct the PSF model from the FLT model and the psf
 bool PM_MODEL_FROM_PSF (pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf)
@@ -279,5 +284,5 @@
     // the 2D PSF model fits polarization terms (E0,E1,E2)
     // convert to shape terms (SXX,SYY,SXY)
-    bool useReff = pmModelUseReff (modelPSF->type);
+    bool useReff = modelPSF->class->useReff;
     if (!pmPSF_FitToModel (out, 0.1, useReff)) {
         psTrace ("psModules.objects", 3, "Failed to fit object at (r,c) = (%.1f,%.1f)", in[PM_PAR_YPOS], in[PM_PAR_XPOS]);
@@ -331,5 +336,5 @@
     // the 2D PSF model fits polarization terms (E0,E1,E2)
     // convert to shape terms (SXX,SYY,SXY)
-    bool useReff = pmModelUseReff (model->type);
+    bool useReff = model->class->useReff;
     if (!pmPSF_FitToModel (PAR, 0.1, useReff)) {
         psTrace ("psModules.objects", 3, "Failed to fit object at (r,c) = (%.1f,%.1f)", Xo, Yo);
Index: /trunk/psModules/src/objects/models/pmModel_GAUSS.h
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_GAUSS.h	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_GAUSS.h	(revision 36857)
@@ -8,4 +8,5 @@
 psF64 pmModelFlux_GAUSS(const psVector *params);
 psF64 pmModelRadius_GAUSS(const psVector *params, psF64 flux);
+psF64 pmModelSetFWHM_GAUSS(const psVector *params, psF64 flux);
 bool pmModelFromPSF_GAUSS(pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf);
 bool  pmModelParamsFromPSF_GAUSS(pmModel *model, const pmPSF *psf, float Xo, float Yo, float Io);
Index: /trunk/psModules/src/objects/models/pmModel_PGAUSS.c
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_PGAUSS.c	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_PGAUSS.c	(revision 36857)
@@ -33,7 +33,7 @@
 #include "pmMoments.h"
 #include "pmModelFuncs.h"
+#include "pmModelClass.h"
 #include "pmModel.h"
 #include "pmModelUtils.h"
-#include "pmModelClass.h"
 #include "pmSourceMasks.h"
 #include "pmSourceExtendedPars.h"
@@ -55,4 +55,5 @@
 # define PM_MODEL_LIMITS          pmModelLimits_PGAUSS
 # define PM_MODEL_RADIUS          pmModelRadius_PGAUSS
+# define PM_MODEL_SET_FWHM        pmModelSetFWHM_PGAUSS
 # define PM_MODEL_FROM_PSF        pmModelFromPSF_PGAUSS
 # define PM_MODEL_PARAMS_FROM_PSF pmModelParamsFromPSF_PGAUSS
@@ -324,4 +325,9 @@
 }
 
+// scale factor is constant for PGAUSS, I found it with the fwhm.sh script
+psF64 PM_MODEL_SET_FWHM (const psVector *params, psF64 sigma) {
+    return (3.0063103*sigma);
+}
+
 bool PM_MODEL_FROM_PSF (pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf)
 {
@@ -344,5 +350,5 @@
     // the 2D PSF model fits polarization terms (E0,E1,E2)
     // convert to shape terms (SXX,SYY,SXY)
-    bool useReff = pmModelUseReff (modelPSF->type);
+    bool useReff = modelPSF->class->useReff;
     if (!pmPSF_FitToModel (out, 0.1, useReff)) {
         psTrace("psModules.objects", 5, "Failed to fit object at (r,c) = (%.1f,%.1f)", in[PM_PAR_YPOS], in[PM_PAR_XPOS]);
@@ -396,5 +402,5 @@
     // the 2D PSF model fits polarization terms (E0,E1,E2)
     // convert to shape terms (SXX,SYY,SXY)
-    bool useReff = pmModelUseReff (model->type);
+    bool useReff = model->class->useReff;
     if (!pmPSF_FitToModel (PAR, 0.1, useReff)) {
         psTrace ("psModules.objects", 3, "Failed to fit object at (r,c) = (%.1f,%.1f)", Xo, Yo);
Index: /trunk/psModules/src/objects/models/pmModel_PGAUSS.h
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_PGAUSS.h	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_PGAUSS.h	(revision 36857)
@@ -8,4 +8,5 @@
 psF64 pmModelFlux_PGAUSS(const psVector *params);
 psF64 pmModelRadius_PGAUSS(const psVector *params, psF64 flux);
+psF64 pmModelSetFWHM_PGAUSS(const psVector *params, psF64 flux);
 bool pmModelFromPSF_PGAUSS(pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf);
 bool  pmModelParamsFromPSF_PGAUSS(pmModel *model, const pmPSF *psf, float Xo, float Yo, float Io);
Index: /trunk/psModules/src/objects/models/pmModel_PS1_V1.c
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_PS1_V1.c	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_PS1_V1.c	(revision 36857)
@@ -35,7 +35,7 @@
 #include "pmMoments.h"
 #include "pmModelFuncs.h"
+#include "pmModelClass.h"
 #include "pmModel.h"
 #include "pmModelUtils.h"
-#include "pmModelClass.h"
 #include "pmSourceMasks.h"
 #include "pmSourceExtendedPars.h"
@@ -57,4 +57,5 @@
 # define PM_MODEL_LIMITS          pmModelLimits_PS1_V1
 # define PM_MODEL_RADIUS          pmModelRadius_PS1_V1
+# define PM_MODEL_SET_FWHM        pmModelSetFWHM_PS1_V1
 # define PM_MODEL_FROM_PSF        pmModelFromPSF_PS1_V1
 # define PM_MODEL_PARAMS_FROM_PSF pmModelParamsFromPSF_PS1_V1
@@ -336,7 +337,54 @@
 }
 
+// I used the script in models/fwhm.sh to generate the trend of FWHM scaling vs the K value
+// FWHM = Scale * Sigma (not that PAR[PM_PAR_SXX] = sigma * sqrt(2)
+//  K : z_hm  : FWHM
+//  0 : 1.000 : 2.83
+//  1 : 0.597 : 2.19
+//  2 : 0.396 : 1.78
+//  3 : 0.291 : 1.53
+//  4 : 0.232 : 1.36
+//  5 : 0.198 : 1.26
+//  6 : 0.169 : 1.16
+//  7 : 0.142 : 1.07
+//  8 : 0.124 : 0.99
+//  9 : 0.118 : 0.97
+// 10 : 0.106 : 0.92
+// 11 : 0.092 : 0.86
+// 12 : 0.091 : 0.85
+// 13 : 0.080 : 0.80
+// 14 : 0.078 : 0.79
+// 15 : 0.073 : 0.76
+// 16 : 0.063 : 0.71
+// 17 : 0.068 : 0.74
+// 18 : 0.056 : 0.67
+// 19 : 0.058 : 0.68
+
+// static float PS1_V1_Core[] = { 0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0, 18.0, 19.0};
+static float PS1_V1_Scale[] = {2.83, 2.19, 1.78, 1.53, 1.36, 1.26, 1.16, 1.07, 0.99, 0.97, 0.92, 0.86, 0.85, 0.80, 0.79, 0.76, 0.71, 0.74, 0.67, 0.68};
+
+psF64 PM_MODEL_SET_FWHM (const psVector *params, psF64 sigma) {
+
+    psF32 *PAR = params->data.F32;
+
+    float core = PAR[PM_PAR_7];
+
+    if (!isfinite(core)) return (2.0*M_SQRT2*sigma);
+
+    // if PS1_V1_Core is defined as a set of integer steps, so we can simplify:
+    int binCore = MAX(0, MIN (19, (int)core));
+
+    float scale = NAN;
+    if (binCore == 0) {
+	scale = (core - binCore + 0) * (PS1_V1_Scale[binCore + 1] - PS1_V1_Scale[binCore + 0]) + PS1_V1_Scale[binCore + 0];
+    } else {
+	scale = (core - binCore - 1) * (PS1_V1_Scale[binCore + 0] - PS1_V1_Scale[binCore - 1]) + PS1_V1_Scale[binCore - 1];
+    }
+
+    return (scale * sigma);
+}
+
 bool PM_MODEL_FROM_PSF (pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf)
 {
-
     psF32 *out = modelPSF->params->data.F32;
     psF32 *in  = modelFLT->params->data.F32;
@@ -357,5 +405,5 @@
     // the 2D PSF model fits polarization terms (E0,E1,E2)
     // convert to shape terms (SXX,SYY,SXY)
-    bool useReff = pmModelUseReff (modelPSF->type);
+    bool useReff = modelPSF->class->useReff;
     if (!pmPSF_FitToModel (out, 0.1, useReff)) {
         psTrace("psModules.objects", 5, "Failed to fit object at (r,c) = (%.1f,%.1f)", in[PM_PAR_YPOS], in[PM_PAR_XPOS]);
@@ -411,5 +459,5 @@
     // convert to shape terms (SXX,SYY,SXY)
     // XXX user-defined value for limit?
-    bool useReff = pmModelUseReff (model->type);
+    bool useReff = model->class->useReff;
     if (!pmPSF_FitToModel (PAR, 0.1, useReff)) {
         psTrace ("psModules.objects", 3, "Failed to fit object at (r,c) = (%.1f,%.1f)", Xo, Yo);
Index: /trunk/psModules/src/objects/models/pmModel_PS1_V1.h
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_PS1_V1.h	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_PS1_V1.h	(revision 36857)
@@ -8,4 +8,5 @@
 psF64 pmModelFlux_PS1_V1(const psVector *params);
 psF64 pmModelRadius_PS1_V1(const psVector *params, psF64 flux);
+psF64 pmModelSetFWHM_PS1_V1(const psVector *params, psF64 flux);
 bool pmModelFromPSF_PS1_V1(pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf);
 bool  pmModelParamsFromPSF_PS1_V1(pmModel *model, const pmPSF *psf, float Xo, float Yo, float Io);
Index: /trunk/psModules/src/objects/models/pmModel_QGAUSS.c
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_QGAUSS.c	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_QGAUSS.c	(revision 36857)
@@ -35,7 +35,7 @@
 #include "pmMoments.h"
 #include "pmModelFuncs.h"
+#include "pmModelClass.h"
 #include "pmModel.h"
 #include "pmModelUtils.h"
-#include "pmModelClass.h"
 #include "pmSourceMasks.h"
 #include "pmSourceExtendedPars.h"
@@ -57,4 +57,5 @@
 # define PM_MODEL_LIMITS          pmModelLimits_QGAUSS
 # define PM_MODEL_RADIUS          pmModelRadius_QGAUSS
+# define PM_MODEL_SET_FWHM        pmModelSetFWHM_QGAUSS
 # define PM_MODEL_FROM_PSF        pmModelFromPSF_QGAUSS
 # define PM_MODEL_PARAMS_FROM_PSF pmModelParamsFromPSF_QGAUSS
@@ -337,4 +338,52 @@
 }
 
+// I used the script in models/fwhm.sh to generate the trend of FWHM scaling vs the K value
+// FWHM = Scale * Sigma (not that PAR[PM_PAR_SXX] = sigma * sqrt(2)
+//  K : z_hm  : FWHM
+//  0 : 1.000 : 2.83
+//  1 : 0.648 : 2.28
+//  2 : 0.430 : 1.85
+//  3 : 0.310 : 1.58
+//  4 : 0.244 : 1.40
+//  5 : 0.200 : 1.26
+//  6 : 0.165 : 1.15
+//  7 : 0.149 : 1.09
+//  8 : 0.125 : 1.00
+//  9 : 0.116 : 0.96
+// 10 : 0.101 : 0.90
+// 11 : 0.095 : 0.87
+// 12 : 0.083 : 0.82
+// 13 : 0.082 : 0.81
+// 14 : 0.080 : 0.80
+// 15 : 0.074 : 0.77
+// 16 : 0.064 : 0.71
+// 17 : 0.068 : 0.74
+// 18 : 0.057 : 0.67
+// 19 : 0.058 : 0.68
+
+// static float QGAUSS_Core[] = { 0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0, 18.0, 19.0};
+static float QGAUSS_Scale[] = {2.83, 2.28, 1.85, 1.58, 1.40, 1.26, 1.15, 1.09, 1.00, 0.96, 0.90, 0.87, 0.82, 0.81, 0.80, 0.77, 0.71, 0.74, 0.67, 0.68};
+
+psF64 PM_MODEL_SET_FWHM (const psVector *params, psF64 sigma) {
+
+    psF32 *PAR = params->data.F32;
+
+    float core = PAR[PM_PAR_7];
+
+    if (!isfinite(core)) return (2.0*M_SQRT2*sigma);
+
+    // QGAUSS_Core is defined as a set of integer steps, so we can simplify:
+    int binCore = MAX(0, MIN (19, (int)core));
+
+    float scale = NAN;
+    if (binCore == 0) {
+	scale = (core - binCore + 0) * (QGAUSS_Scale[binCore + 1] - QGAUSS_Scale[binCore + 0]) + QGAUSS_Scale[binCore + 0];
+    } else {
+	scale = (core - binCore - 1) * (QGAUSS_Scale[binCore + 0] - QGAUSS_Scale[binCore - 1]) + QGAUSS_Scale[binCore - 1];
+    }
+
+    return (scale * sigma);
+}
+
 bool PM_MODEL_FROM_PSF (pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf)
 {
@@ -358,5 +407,5 @@
     // the 2D PSF model fits polarization terms (E0,E1,E2)
     // convert to shape terms (SXX,SYY,SXY)
-    bool useReff = pmModelUseReff (modelPSF->type);
+    bool useReff = modelPSF->class->useReff;
     if (!pmPSF_FitToModel (out, 0.1, useReff)) {
         psTrace("psModules.objects", 5, "Failed to fit object at (r,c) = (%.1f,%.1f)", in[PM_PAR_YPOS], in[PM_PAR_XPOS]);
@@ -416,5 +465,5 @@
     // the 2D PSF model fits polarization terms (E0,E1,E2)
     // convert to shape terms (SXX,SYY,SXY)
-    bool useReff = pmModelUseReff (model->type);
+    bool useReff = model->class->useReff;
     if (!pmPSF_FitToModel (PAR, 0.1, useReff)) {
         psTrace ("psModules.objects", 3, "Failed to fit object at (r,c) = (%.1f,%.1f)", Xo, Yo);
Index: /trunk/psModules/src/objects/models/pmModel_QGAUSS.h
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_QGAUSS.h	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_QGAUSS.h	(revision 36857)
@@ -8,4 +8,5 @@
 psF64 pmModelFlux_QGAUSS(const psVector *params);
 psF64 pmModelRadius_QGAUSS(const psVector *params, psF64 flux);
+psF64 pmModelSetFWHM_QGAUSS(const psVector *params, psF64 flux);
 bool pmModelFromPSF_QGAUSS(pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf);
 bool  pmModelParamsFromPSF_QGAUSS(pmModel *model, const pmPSF *psf, float Xo, float Yo, float Io);
Index: /trunk/psModules/src/objects/models/pmModel_RGAUSS.c
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_RGAUSS.c	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_RGAUSS.c	(revision 36857)
@@ -34,7 +34,7 @@
 #include "pmMoments.h"
 #include "pmModelFuncs.h"
+#include "pmModelClass.h"
 #include "pmModel.h"
 #include "pmModelUtils.h"
-#include "pmModelClass.h"
 #include "pmSourceMasks.h"
 #include "pmSourceExtendedPars.h"
@@ -56,4 +56,5 @@
 # define PM_MODEL_LIMITS          pmModelLimits_RGAUSS
 # define PM_MODEL_RADIUS          pmModelRadius_RGAUSS
+# define PM_MODEL_SET_FWHM        pmModelSetFWHM_RGAUSS
 # define PM_MODEL_FROM_PSF        pmModelFromPSF_RGAUSS
 # define PM_MODEL_PARAMS_FROM_PSF pmModelParamsFromPSF_RGAUSS
@@ -330,4 +331,8 @@
 }
 
+psF64 PM_MODEL_SET_FWHM (const psVector *params, psF64 sigma) {
+  return (NAN);
+}
+
 bool PM_MODEL_FROM_PSF (pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf)
 {
@@ -351,5 +356,5 @@
     // the 2D PSF model fits polarization terms (E0,E1,E2)
     // convert to shape terms (SXX,SYY,SXY)
-    bool useReff = pmModelUseReff (modelPSF->type);
+    bool useReff = modelPSF->class->useReff;
     if (!pmPSF_FitToModel (out, 0.1, useReff)) {
         psTrace("psModules.objects", 5, "Failed to fit object at (r,c) = (%.1f,%.1f)", in[PM_PAR_YPOS], in[PM_PAR_XPOS]);
@@ -404,5 +409,5 @@
     // the 2D PSF model fits polarization terms (E0,E1,E2)
     // convert to shape terms (SXX,SYY,SXY)
-    bool useReff = pmModelUseReff (model->type);
+    bool useReff = model->class->useReff;
     if (!pmPSF_FitToModel (PAR, 0.1, useReff)) {
         psTrace ("psModules.objects", 3, "Failed to fit object at (r,c) = (%.1f,%.1f)", Xo, Yo);
Index: /trunk/psModules/src/objects/models/pmModel_RGAUSS.h
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_RGAUSS.h	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_RGAUSS.h	(revision 36857)
@@ -8,4 +8,5 @@
 psF64 pmModelFlux_RGAUSS(const psVector *params);
 psF64 pmModelRadius_RGAUSS(const psVector *params, psF64 flux);
+psF64 pmModelSetFWHM_RGAUSS(const psVector *params, psF64 flux);
 bool pmModelFromPSF_RGAUSS(pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf);
 bool  pmModelParamsFromPSF_RGAUSS(pmModel *model, const pmPSF *psf, float Xo, float Yo, float Io);
Index: /trunk/psModules/src/objects/models/pmModel_SERSIC.c
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_SERSIC.c	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_SERSIC.c	(revision 36857)
@@ -43,7 +43,7 @@
 #include "pmMoments.h"
 #include "pmModelFuncs.h"
+#include "pmModelClass.h"
 #include "pmModel.h"
 #include "pmModelUtils.h"
-#include "pmModelClass.h"
 #include "pmSourceMasks.h"
 #include "pmSourceExtendedPars.h"
@@ -66,4 +66,5 @@
 # define PM_MODEL_LIMITS          pmModelLimits_SERSIC
 # define PM_MODEL_RADIUS          pmModelRadius_SERSIC
+# define PM_MODEL_SET_FWHM        pmModelSetFWHM_SERSIC
 # define PM_MODEL_FROM_PSF        pmModelFromPSF_SERSIC
 # define PM_MODEL_PARAMS_FROM_PSF pmModelParamsFromPSF_SERSIC
@@ -357,4 +358,8 @@
 }
 
+psF64 PM_MODEL_SET_FWHM (const psVector *params, psF64 sigma) {
+  return (NAN);
+}
+
 bool PM_MODEL_FROM_PSF (pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf)
 {
@@ -378,5 +383,5 @@
     // the 2D PSF model fits polarization terms (E0,E1,E2)
     // convert to shape terms (SXX,SYY,SXY)
-    bool useReff = pmModelUseReff (modelPSF->type);
+    bool useReff = modelPSF->class->useReff;
     if (!pmPSF_FitToModel (out, 0.1, useReff)) {
         psTrace("psModules.objects", 5, "Failed to fit object at (r,c) = (%.1f,%.1f)", in[PM_PAR_YPOS], in[PM_PAR_XPOS]);
@@ -432,5 +437,5 @@
     // convert to shape terms (SXX,SYY,SXY)
     // XXX user-defined value for limit?
-    bool useReff = pmModelUseReff (model->type);
+    bool useReff = model->class->useReff;
     if (!pmPSF_FitToModel (PAR, 0.1, useReff)) {
         psTrace ("psModules.objects", 3, "Failed to fit object at (r,c) = (%.1f,%.1f)", Xo, Yo);
Index: /trunk/psModules/src/objects/models/pmModel_SERSIC.h
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_SERSIC.h	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_SERSIC.h	(revision 36857)
@@ -8,4 +8,5 @@
 psF64 pmModelFlux_SERSIC(const psVector *params);
 psF64 pmModelRadius_SERSIC(const psVector *params, psF64 flux);
+psF64 pmModelSetFWHM_SERSIC(const psVector *params, psF64 flux);
 bool pmModelFromPSF_SERSIC(pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf);
 bool  pmModelParamsFromPSF_SERSIC(pmModel *model, const pmPSF *psf, float Xo, float Yo, float Io);
Index: /trunk/psModules/src/objects/models/pmModel_TRAIL.c
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_TRAIL.c	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_TRAIL.c	(revision 36857)
@@ -5,4 +5,5 @@
  * The meaning of the parameters may thus vary depending on the specifics of the model.
  * All models which are used as a PSF representations share a few parameters, for which #
+#include "pmModelClass.h"
  * define names are listed in pmModel.h:
 
@@ -33,7 +34,7 @@
 #include "pmMoments.h"
 #include "pmModelFuncs.h"
+#include "pmModelClass.h"
 #include "pmModel.h"
 #include "pmModelUtils.h"
-#include "pmModelClass.h"
 #include "pmSourceMasks.h"
 #include "pmSourceExtendedPars.h"
@@ -55,4 +56,5 @@
 # define PM_MODEL_LIMITS          pmModelLimits_TRAIL
 # define PM_MODEL_RADIUS          pmModelRadius_TRAIL
+# define PM_MODEL_SET_FWHM        pmModelSetFWHM_TRAIL
 # define PM_MODEL_FROM_PSF        pmModelFromPSF_TRAIL
 # define PM_MODEL_PARAMS_FROM_PSF pmModelParamsFromPSF_TRAIL
@@ -352,5 +354,5 @@
 
     psF32 *psfPAR  = source->modelPSF->params->data.F32;
-    bool useReff = pmModelUseReff (source->modelPSF->type);
+    bool useReff = source->modelPSF->class->useReff;
 
     psEllipseAxes psfAxes;
@@ -413,4 +415,8 @@
     // PAR_LENGTH is the unconvolved length.  add a bit for safety
     return (0.5*PAR[PM_PAR_LENGTH] + 2);
+}
+
+psF64 PM_MODEL_SET_FWHM (const psVector *params, psF64 sigma) {
+  return (NAN);
 }
 
Index: /trunk/psModules/src/objects/models/pmModel_TRAIL.h
===================================================================
--- /trunk/psModules/src/objects/models/pmModel_TRAIL.h	(revision 36856)
+++ /trunk/psModules/src/objects/models/pmModel_TRAIL.h	(revision 36857)
@@ -8,4 +8,5 @@
 psF64 pmModelFlux_TRAIL(const psVector *params);
 psF64 pmModelRadius_TRAIL(const psVector *params, psF64 flux);
+psF64 pmModelSetFWHM_TRAIL(const psVector *params, psF64 flux);
 bool pmModelFromPSF_TRAIL(pmModel *modelPSF, pmModel *modelFLT, const pmPSF *psf);
 bool  pmModelParamsFromPSF_TRAIL(pmModel *model, const pmPSF *psf, float Xo, float Yo, float Io);