Get camera length from HDF5 if required

6 files changed, 169 insertions, 72 deletions

diff --git a/doc/examples/cspad-feb2011.geom b/doc/examples/cspad-feb2011.geom
index e6448293..94bf94fe 100644
--- a/doc/examples/cspad-feb2011.geom
+++ b/doc/examples/cspad-feb2011.geom
@@ -8,7 +8,7 @@ n_panels = 64
 0/badrow_direction = -
 0/res = 9090.91
 0/peak_sep = 6.0
-0/clen = 77.0e-3
+0/clen = /LCLS/detectorPosition
 0/fs = +y
 0/ss = -x
 0/corner_x = 429.39
@@ -23,7 +23,7 @@ n_panels = 64
 1/badrow_direction = -
 1/res = 9090.91
 1/peak_sep = 6.0
-1/clen = 77.0e-3
+1/clen = /LCLS/detectorPosition
 1/fs = +y
 1/ss = -x
 1/corner_x = 429.39
@@ -38,7 +38,7 @@ n_panels = 64
 2/badrow_direction = -
 2/res = 9090.91
 2/peak_sep = 6.0
-2/clen = 77.0e-3
+2/clen = /LCLS/detectorPosition
 2/fs = -x
 2/ss = -y
 2/corner_x = 17.36
@@ -53,7 +53,7 @@ n_panels = 64
 3/badrow_direction = -
 3/res = 9090.91
 3/peak_sep = 6.0
-3/clen = 77.0e-3
+3/clen = /LCLS/detectorPosition
 3/fs = -x
 3/ss = -y
 3/corner_x = -181.64
@@ -68,7 +68,7 @@ n_panels = 64
 4/badrow_direction = -
 4/res = 9090.91
 4/peak_sep = 6.0
-4/clen = 77.0e-3
+4/clen = /LCLS/detectorPosition
 4/fs = -y
 4/ss = +x
 4/corner_x = -428.12
@@ -83,7 +83,7 @@ n_panels = 64
 5/badrow_direction = -
 5/res = 9090.91
 5/peak_sep = 6.0
-5/clen = 77.0e-3
+5/clen = /LCLS/detectorPosition
 5/fs = -y
 5/ss = +x
 5/corner_x = -428.12
@@ -98,7 +98,7 @@ n_panels = 64
 6/badrow_direction = -
 6/res = 9090.91
 6/peak_sep = 6.0
-6/clen = 77.0e-3
+6/clen = /LCLS/detectorPosition
 6/fs = +x
 6/ss = +y
 6/corner_x = -14.95
@@ -113,7 +113,7 @@ n_panels = 64
 7/badrow_direction = -
 7/res = 9090.91
 7/peak_sep = 6.0
-7/clen = 77.0e-3
+7/clen = /LCLS/detectorPosition
 7/fs = +x
 7/ss = +y
 7/corner_x = 184.05
@@ -128,7 +128,7 @@ n_panels = 64
 8/badrow_direction = -
 8/res = 9090.91
 8/peak_sep = 6.0
-8/clen = 77.0e-3
+8/clen = /LCLS/detectorPosition
 8/fs = +y
 8/ss = -x
 8/corner_x = 214.99
@@ -143,7 +143,7 @@ n_panels = 64
 9/badrow_direction = -
 9/res = 9090.91
 9/peak_sep = 6.0
-9/clen = 77.0e-3
+9/clen = /LCLS/detectorPosition
 9/fs = +y
 9/ss = -x
 9/corner_x = 214.99
@@ -158,7 +158,7 @@ n_panels = 64
 10/badrow_direction = -
 10/res = 9090.91
 10/peak_sep = 6.0
-10/clen = 77.0e-3
+10/clen = /LCLS/detectorPosition
 10/fs = -x
 10/ss = -y
 10/corner_x = 16.59
@@ -173,7 +173,7 @@ n_panels = 64
 11/badrow_direction = -
 11/res = 9090.91
 11/peak_sep = 6.0
-11/clen = 77.0e-3
+11/clen = /LCLS/detectorPosition
 11/fs = -x
 11/ss = -y
 11/corner_x = -182.41
@@ -188,7 +188,7 @@ n_panels = 64
 12/badrow_direction = -
 12/res = 9090.91
 12/peak_sep = 6.0
-12/clen = 77.0e-3
+12/clen = /LCLS/detectorPosition
 12/fs = -y
 12/ss = +x
 12/corner_x = -212.64
@@ -203,7 +203,7 @@ n_panels = 64
 13/badrow_direction = -
 13/res = 9090.91
 13/peak_sep = 6.0
-13/clen = 77.0e-3
+13/clen = /LCLS/detectorPosition
 13/fs = -y
 13/ss = +x
 13/corner_x = -212.64
@@ -218,7 +218,7 @@ n_panels = 64
 14/badrow_direction = -
 14/res = 9090.91
 14/peak_sep = 6.0
-14/clen = 77.0e-3
+14/clen = /LCLS/detectorPosition
 14/fs = +x
 14/ss = +y
 14/corner_x = -11.44
@@ -233,7 +233,7 @@ n_panels = 64
 15/badrow_direction = -
 15/res = 9090.91
 15/peak_sep = 6.0
-15/clen = 77.0e-3
+15/clen = /LCLS/detectorPosition
 15/fs = +x
 15/ss = +y
 15/corner_x = 187.56
@@ -248,7 +248,7 @@ n_panels = 64
 16/badrow_direction = -
 16/res = 9090.91
 16/peak_sep = 6.0
-16/clen = 77.0e-3
+16/clen = /LCLS/detectorPosition
 16/fs = -x
 16/ss = -y
 16/corner_x = 851.64
@@ -263,7 +263,7 @@ n_panels = 64
 17/badrow_direction = -
 17/res = 9090.91
 17/peak_sep = 6.0
-17/clen = 77.0e-3
+17/clen = /LCLS/detectorPosition
 17/fs = -x
 17/ss = -y
 17/corner_x = 652.64
@@ -278,7 +278,7 @@ n_panels = 64
 18/badrow_direction = -
 18/res = 9090.91
 18/peak_sep = 6.0
-18/clen = 77.0e-3
+18/clen = /LCLS/detectorPosition
 18/fs = -y
 18/ss = +x
 18/corner_x = -381.23
@@ -293,7 +293,7 @@ n_panels = 64
 19/badrow_direction = -
 19/res = 9090.91
 19/peak_sep = 6.0
-19/clen = 77.0e-3
+19/clen = /LCLS/detectorPosition
 19/fs = -y
 19/ss = +x
 19/corner_x = -381.23
@@ -308,7 +308,7 @@ n_panels = 64
 20/badrow_direction = -
 20/res = 9090.91
 20/peak_sep = 6.0
-20/clen = 77.0e-3
+20/clen = /LCLS/detectorPosition
 20/fs = +x
 20/ss = +y
 20/corner_x = -849.25
@@ -323,7 +323,7 @@ n_panels = 64
 21/badrow_direction = -
 21/res = 9090.91
 21/peak_sep = 6.0
-21/clen = 77.0e-3
+21/clen = /LCLS/detectorPosition
 21/fs = +x
 21/ss = +y
 21/corner_x = -650.25
@@ -338,7 +338,7 @@ n_panels = 64
 22/badrow_direction = -
 22/res = 9090.91
 22/peak_sep = 6.0
-22/clen = 77.0e-3
+22/clen = /LCLS/detectorPosition
 22/fs = +y
 22/ss = -x
 22/corner_x = 389.50
@@ -353,7 +353,7 @@ n_panels = 64
 23/badrow_direction = -
 23/res = 9090.91
 23/peak_sep = 6.0
-23/clen = 77.0e-3
+23/clen = /LCLS/detectorPosition
 23/fs = +y
 23/ss = -x
 23/corner_x = 389.50
@@ -368,7 +368,7 @@ n_panels = 64
 24/badrow_direction = -
 24/res = 9090.91
 24/peak_sep = 6.0
-24/clen = 77.0e-3
+24/clen = /LCLS/detectorPosition
 24/fs = -x
 24/ss = -y
 24/corner_x = 855.29
@@ -383,7 +383,7 @@ n_panels = 64
 25/badrow_direction = -
 25/res = 9090.91
 25/peak_sep = 6.0
-25/clen = 77.0e-3
+25/clen = /LCLS/detectorPosition
 25/fs = -x
 25/ss = -y
 25/corner_x = 656.29
@@ -398,7 +398,7 @@ n_panels = 64
 26/badrow_direction = -
 26/res = 9090.91
 26/peak_sep = 6.0
-26/clen = 77.0e-3
+26/clen = /LCLS/detectorPosition
 26/fs = -y
 26/ss = +x
 26/corner_x = -167.72
@@ -413,7 +413,7 @@ n_panels = 64
 27/badrow_direction = -
 27/res = 9090.91
 27/peak_sep = 6.0
-27/clen = 77.0e-3
+27/clen = /LCLS/detectorPosition
 27/fs = -y
 27/ss = +x
 27/corner_x = -167.72
@@ -428,7 +428,7 @@ n_panels = 64
 28/badrow_direction = -
 28/res = 9090.91
 28/peak_sep = 6.0
-28/clen = 77.0e-3
+28/clen = /LCLS/detectorPosition
 28/fs = +x
 28/ss = +y
 28/corner_x = -847.07
@@ -443,7 +443,7 @@ n_panels = 64
 29/badrow_direction = -
 29/res = 9090.91
 29/peak_sep = 6.0
-29/clen = 77.0e-3
+29/clen = /LCLS/detectorPosition
 29/fs = +x
 29/ss = +y
 29/corner_x = -648.07
@@ -458,7 +458,7 @@ n_panels = 64
 30/badrow_direction = -
 30/res = 9090.91
 30/peak_sep = 6.0
-30/clen = 77.0e-3
+30/clen = /LCLS/detectorPosition
 30/fs = +y
 30/ss = -x
 30/corner_x = 174.81
@@ -473,7 +473,7 @@ n_panels = 64
 31/badrow_direction = -
 31/res = 9090.91
 31/peak_sep = 6.0
-31/clen = 77.0e-3
+31/clen = /LCLS/detectorPosition
 31/fs = +y
 31/ss = -x
 31/corner_x = 174.81
@@ -488,7 +488,7 @@ n_panels = 64
 32/badrow_direction = -
 32/res = 9090.91
 32/peak_sep = 6.0
-32/clen = 77.0e-3
+32/clen = /LCLS/detectorPosition
 32/fs = -y
 32/ss = +x
 32/corner_x = 450.39
@@ -503,7 +503,7 @@ n_panels = 64
 33/badrow_direction = -
 33/res = 9090.91
 33/peak_sep = 6.0
-33/clen = 77.0e-3
+33/clen = /LCLS/detectorPosition
 33/fs = -y
 33/ss = +x
 33/corner_x = 450.39
@@ -518,7 +518,7 @@ n_panels = 64
 34/badrow_direction = -
 34/res = 9090.91
 34/peak_sep = 6.0
-34/clen = 77.0e-3
+34/clen = /LCLS/detectorPosition
 34/fs = +x
 34/ss = +y
 34/corner_x = -808.26
@@ -533,7 +533,7 @@ n_panels = 64
 35/badrow_direction = -
 35/res = 9090.91
 35/peak_sep = 6.0
-35/clen = 77.0e-3
+35/clen = /LCLS/detectorPosition
 35/fs = +x
 35/ss = +y
 35/corner_x = -609.26
@@ -548,7 +548,7 @@ n_panels = 64
 36/badrow_direction = -
 36/res = 9090.91
 36/peak_sep = 6.0
-36/clen = 77.0e-3
+36/clen = /LCLS/detectorPosition
 36/fs = +y
 36/ss = -x
 36/corner_x = -450.89
@@ -563,7 +563,7 @@ n_panels = 64
 37/badrow_direction = -
 37/res = 9090.91
 37/peak_sep = 6.0
-37/clen = 77.0e-3
+37/clen = /LCLS/detectorPosition
 37/fs = +y
 37/ss = -x
 37/corner_x = -450.89
@@ -578,7 +578,7 @@ n_panels = 64
 38/badrow_direction = -
 38/res = 9090.91
 38/peak_sep = 6.0
-38/clen = 77.0e-3
+38/clen = /LCLS/detectorPosition
 38/fs = -x
 38/ss = -y
 38/corner_x = 799.39
@@ -593,7 +593,7 @@ n_panels = 64
 39/badrow_direction = -
 39/res = 9090.91
 39/peak_sep = 6.0
-39/clen = 77.0e-3
+39/clen = /LCLS/detectorPosition
 39/fs = -x
 39/ss = -y
 39/corner_x = 600.39
@@ -608,7 +608,7 @@ n_panels = 64
 40/badrow_direction = -
 40/res = 9090.91
 40/peak_sep = 6.0
-40/clen = 77.0e-3
+40/clen = /LCLS/detectorPosition
 40/fs = -y
 40/ss = +x
 40/corner_x = 642.39
@@ -623,7 +623,7 @@ n_panels = 64
 41/badrow_direction = -
 41/res = 9090.91
 41/peak_sep = 6.0
-41/clen = 77.0e-3
+41/clen = /LCLS/detectorPosition
 41/fs = -y
 41/ss = +x
 41/corner_x = 642.39
@@ -638,7 +638,7 @@ n_panels = 64
 42/badrow_direction = -
 42/res = 9090.91
 42/peak_sep = 6.0
-42/clen = 77.0e-3
+42/clen = /LCLS/detectorPosition
 42/fs = +x
 42/ss = +y
 42/corner_x = -809.61
@@ -653,7 +653,7 @@ n_panels = 64
 43/badrow_direction = -
 43/res = 9090.91
 43/peak_sep = 6.0
-43/clen = 77.0e-3
+43/clen = /LCLS/detectorPosition
 43/fs = +x
 43/ss = +y
 43/corner_x = -610.61
@@ -668,7 +668,7 @@ n_panels = 64
 44/badrow_direction = -
 44/res = 9090.91
 44/peak_sep = 6.0
-44/clen = 77.0e-3
+44/clen = /LCLS/detectorPosition
 44/fs = +y
 44/ss = -x
 44/corner_x = -657.61
@@ -683,7 +683,7 @@ n_panels = 64
 45/badrow_direction = -
 45/res = 9090.91
 45/peak_sep = 6.0
-45/clen = 77.0e-3
+45/clen = /LCLS/detectorPosition
 45/fs = +y
 45/ss = -x
 45/corner_x = -657.61
@@ -698,7 +698,7 @@ n_panels = 64
 46/badrow_direction = -
 46/res = 9090.91
 46/peak_sep = 6.0
-46/clen = 77.0e-3
+46/clen = /LCLS/detectorPosition
 46/fs = -x
 46/ss = -y
 46/corner_x = 793.39
@@ -713,7 +713,7 @@ n_panels = 64
 47/badrow_direction = -
 47/res = 9090.91
 47/peak_sep = 6.0
-47/clen = 77.0e-3
+47/clen = /LCLS/detectorPosition
 47/fs = -x
 47/ss = -y
 47/corner_x = 594.39
@@ -728,7 +728,7 @@ n_panels = 64
 48/badrow_direction = -
 48/res = 9090.91
 48/peak_sep = 6.0
-48/clen = 77.0e-3
+48/clen = /LCLS/detectorPosition
 48/fs = -x
 48/ss = -y
 48/corner_x = 417.94
@@ -743,7 +743,7 @@ n_panels = 64
 49/badrow_direction = -
 49/res = 9090.91
 49/peak_sep = 6.0
-49/clen = 77.0e-3
+49/clen = /LCLS/detectorPosition
 49/fs = -x
 49/ss = -y
 49/corner_x = 218.94
@@ -758,7 +758,7 @@ n_panels = 64
 50/badrow_direction = -
 50/res = 9090.91
 50/peak_sep = 6.0
-50/clen = 77.0e-3
+50/clen = /LCLS/detectorPosition
 50/fs = -y
 50/ss = +x
 50/corner_x = -783.68
@@ -773,7 +773,7 @@ n_panels = 64
 51/badrow_direction = -
 51/res = 9090.91
 51/peak_sep = 6.0
-51/clen = 77.0e-3
+51/clen = /LCLS/detectorPosition
 51/fs = -y
 51/ss = +x
 51/corner_x = -783.68
@@ -788,7 +788,7 @@ n_panels = 64
 52/badrow_direction = -
 52/res = 9090.91
 52/peak_sep = 6.0
-52/clen = 77.0e-3
+52/clen = /LCLS/detectorPosition
 52/fs = +x
 52/ss = +y
 52/corner_x = -433.03
@@ -803,7 +803,7 @@ n_panels = 64
 53/badrow_direction = -
 53/res = 9090.91
 53/peak_sep = 6.0
-53/clen = 77.0e-3
+53/clen = /LCLS/detectorPosition
 53/fs = +x
 53/ss = +y
 53/corner_x = -234.03
@@ -818,7 +818,7 @@ n_panels = 64
 54/badrow_direction = -
 54/res = 9090.91
 54/peak_sep = 6.0
-54/clen = 77.0e-3
+54/clen = /LCLS/detectorPosition
 54/fs = +y
 54/ss = -x
 54/corner_x = 835.39
@@ -833,7 +833,7 @@ n_panels = 64
 55/badrow_direction = -
 55/res = 9090.91
 55/peak_sep = 6.0
-55/clen = 77.0e-3
+55/clen = /LCLS/detectorPosition
 55/fs = +y
 55/ss = -x
 55/corner_x = 835.39
@@ -848,7 +848,7 @@ n_panels = 64
 56/badrow_direction = -
 56/res = 9090.91
 56/peak_sep = 6.0
-56/clen = 77.0e-3
+56/clen = /LCLS/detectorPosition
 56/fs = -x
 56/ss = -y
 56/corner_x = 425.57
@@ -863,7 +863,7 @@ n_panels = 64
 57/badrow_direction = -
 57/res = 9090.91
 57/peak_sep = 6.0
-57/clen = 77.0e-3
+57/clen = /LCLS/detectorPosition
 57/fs = -x
 57/ss = -y
 57/corner_x = 226.57
@@ -878,7 +878,7 @@ n_panels = 64
 58/badrow_direction = -
 58/res = 9090.91
 58/peak_sep = 6.0
-58/clen = 77.0e-3
+58/clen = /LCLS/detectorPosition
 58/fs = -y
 58/ss = +x
 58/corner_x = -572.18
@@ -893,7 +893,7 @@ n_panels = 64
 59/badrow_direction = -
 59/res = 9090.91
 59/peak_sep = 6.0
-59/clen = 77.0e-3
+59/clen = /LCLS/detectorPosition
 59/fs = -y
 59/ss = +x
 59/corner_x = -572.18
@@ -908,7 +908,7 @@ n_panels = 64
 60/badrow_direction = -
 60/res = 9090.91
 60/peak_sep = 6.0
-60/clen = 77.0e-3
+60/clen = /LCLS/detectorPosition
 60/fs = +x
 60/ss = +y
 60/corner_x = -415.37
@@ -923,7 +923,7 @@ n_panels = 64
 61/badrow_direction = -
 61/res = 9090.91
 61/peak_sep = 6.0
-61/clen = 77.0e-3
+61/clen = /LCLS/detectorPosition
 61/fs = +x
 61/ss = +y
 61/corner_x = -216.37
@@ -938,7 +938,7 @@ n_panels = 64
 62/badrow_direction = -
 62/res = 9090.91
 62/peak_sep = 6.0
-62/clen = 77.0e-3
+62/clen = /LCLS/detectorPosition
 62/fs = +y
 62/ss = -x
 62/corner_x = 577.59
@@ -953,10 +953,9 @@ n_panels = 64
 63/badrow_direction = -
 63/res = 9090.91
 63/peak_sep = 6.0
-63/clen = 77.0e-3
+63/clen = /LCLS/detectorPosition
 63/fs = +y
 63/ss = -x
 63/corner_x = 577.59
 63/corner_y = -227.89
 63/no_index = 0
-
diff --git a/src/detector.c b/src/detector.c
index e4f15aff..7d2cb513 100644
--- a/src/detector.c
+++ b/src/detector.c
@@ -21,6 +21,7 @@
 #include "diffraction.h"
 #include "detector.h"
 #include "beam-parameters.h"
+#include "hdf5-file.h"
 
 
 static int atob(const char *a)
@@ -240,6 +241,24 @@ struct panel *find_panel(struct detector *det, int x, int y)
 }
 
 
+void fill_in_values(struct detector *det, struct hdfile *f)
+{
+	int i;
+
+	for ( i=0; i<det->n_panels; i++ ) {
+
+		struct panel *p = &det->panels[i];
+
+		if ( p->clen_from != NULL ) {
+			p->clen = get_value(f, p->clen_from) * 1.0e-3;
+			free(p->clen_from);
+			p->clen_from = NULL;
+		}
+
+	}
+}
+
+
 struct detector *get_detector_geometry(const char *filename)
 {
 	FILE *fh;
@@ -359,7 +378,18 @@ struct detector *get_detector_geometry(const char *filename)
 		} else if ( strcmp(path[1], "corner_y") == 0 ) {
 			det->panels[np].cy = atof(bits[2]);
 		} else if ( strcmp(path[1], "clen") == 0 ) {
-			det->panels[np].clen = atof(bits[2]);
+
+			char *end;
+			double v = strtod(bits[2], &end);
+			if ( end == bits[2] ) {
+				/* This means "fill in later" */
+				det->panels[np].clen = -1.0;
+				det->panels[np].clen_from = strdup(bits[2]);
+			} else {
+				det->panels[np].clen = v;
+				det->panels[np].clen_from = NULL;
+			}
+
 		} else if ( strcmp(path[1], "res") == 0 ) {
 			det->panels[np].res = atof(bits[2]);
 		} else if ( strcmp(path[1], "peak_sep") == 0 ) {
@@ -442,7 +472,8 @@ struct detector *get_detector_geometry(const char *filename)
 			      " panel %i\n", i);
 			reject = 1;
 		}
-		if ( det->panels[i].clen == -1 ) {
+		if ( (det->panels[i].clen < 0.0)
+		  && (det->panels[i].clen_from == NULL) ) {
 			ERROR("Please specify the camera length for"
 			      " panel %i\n", i);
 			reject = 1;
diff --git a/src/detector.h b/src/detector.h
index 703c79ae..e9b2112f 100644
--- a/src/detector.h
+++ b/src/detector.h
@@ -17,22 +17,26 @@
 #define DETECTOR_H
 
 struct image;
+struct hdfile;
 
+#include "hdf5-file.h"
 #include "image.h"
 
+
 struct panel
 {
 	int      min_fs;  /* Smallest FS value considered to be in the panel */
 	int      max_fs;  /* Largest FS value considered to be in this panel */
 	int      min_ss;  /* ... and so on */
 	int      max_ss;
-	float    cx;       /* Location of corner (min_fs,min_ss) in pixels */
-	float    cy;
-	float    clen;     /* Camera length in metres */
-	float    res;      /* Resolution in pixels per metre */
+	double   cx;       /* Location of corner (min_fs,min_ss) in pixels */
+	double   cy;
+	double   clen;     /* Camera length in metres */
+	char    *clen_from;
+	double   res;      /* Resolution in pixels per metre */
 	char     badrow;   /* 'x' or 'y' */
 	int      no_index; /* Don't index peaks in this panel if non-zero */
-	float    peak_sep; /* Characteristic peak separation */
+	double   peak_sep; /* Characteristic peak separation */
 
 	signed int fsx;
 	signed int fsy;
@@ -58,11 +62,16 @@ extern void record_image(struct image *image, int do_poisson);
 extern struct panel *find_panel(struct detector *det, int x, int y);
 
 extern struct detector *get_detector_geometry(const char *filename);
+
 extern void free_detector_geometry(struct detector *det);
 
 extern struct detector *simple_geometry(const struct image *image);
+
 extern void get_pixel_extents(struct detector *det,
                               double *min_x, double *min_y,
                               double *max_x, double *max_y);
 
+extern void fill_in_values(struct detector *det, struct hdfile *f);
+
+
 #endif	/* DETECTOR_H */
diff --git a/src/displaywindow.c b/src/displaywindow.c
index 0af864fc..fe578266 100644
--- a/src/displaywindow.c
+++ b/src/displaywindow.c
@@ -656,6 +656,7 @@ static int load_geometry_file(DisplayWindow *dw, struct image *image,
 		displaywindow_error(dw, "Failed to load geometry file");
 		return -1;
 	}
+	fill_in_values(geom, dw->hdfile);
 
 	if ( (1+geom->max_fs != dw->image->width)
 	  || (1+geom->max_ss != dw->image->height) ) {
diff --git a/src/hdf5-file.c b/src/hdf5-file.c
index 33d3f95a..313489e4 100644
--- a/src/hdf5-file.c
+++ b/src/hdf5-file.c
@@ -475,6 +475,62 @@ static int looks_like_image(hid_t h)
 }
 
 
+double get_value(struct hdfile *f, const char *name)
+{
+	hid_t dh;
+	hid_t sh;
+	hsize_t size;
+	hsize_t max_size;
+	hid_t type;
+	hid_t class;
+	herr_t r;
+	double buf;
+
+	dh = H5Dopen2(f->fh, name, H5P_DEFAULT);
+	if ( dh < 0 ) {
+		ERROR("Couldn't open data\n");
+		return 0.0;
+	}
+
+	type = H5Dget_type(dh);
+	class = H5Tget_class(type);
+
+	if ( class != H5T_FLOAT ) {
+		ERROR("Not a floating point value.\n");
+		H5Tclose(type);
+		H5Dclose(dh);
+		return 0.0;
+	}
+
+	sh = H5Dget_space(dh);
+	if ( H5Sget_simple_extent_ndims(sh) != 1 ) {
+		ERROR("Not a scalar value.\n");
+		H5Tclose(type);
+		H5Dclose(dh);
+		return 0.0;
+	}
+
+	H5Sget_simple_extent_dims(sh, &size, &max_size);
+	if ( size != 1 ) {
+		ERROR("Not a scalar value.\n");
+		H5Tclose(type);
+		H5Dclose(dh);
+		return 0.0;
+	}
+
+	r = H5Dread(dh, H5T_NATIVE_DOUBLE, H5S_ALL, H5S_ALL,
+	            H5P_DEFAULT, &buf);
+	if ( r < 0 )  {
+		ERROR("Couldn't read value.\n");
+		H5Tclose(type);
+		H5Dclose(dh);
+		return 0.0;
+	}
+
+	return buf;
+}
+
+
 char *hdfile_get_string_value(struct hdfile *f, const char *name)
 {
 	hid_t dh;
diff --git a/src/hdf5-file.h b/src/hdf5-file.h
index 342dfe72..7a0d4382 100644
--- a/src/hdf5-file.h
+++ b/src/hdf5-file.h
@@ -41,5 +41,6 @@ extern void hdfile_close(struct hdfile *f);
 
 extern char *hdfile_get_string_value(struct hdfile *f, const char *name);
 extern int get_peaks(struct image *image, struct hdfile *f);
+extern double get_value(struct hdfile *f, const char *name);
 
 #endif	/* HDF5_H */