bugfixes in pshell import and preview

changes:
- fix null string exception in preview
- fix transposition of two-dimensional datasets

pearl/pearl-pshell-import.ipf

@@ -66,6 +66,15 @@ strconstant kScanDimLabel = "scan"
 /// This label may be used to store the parameters for the `setscale d` operation.
 strconstant kDataDimLabel = "data"
 
+/// List of preferred datasets to load for preview
+strconstant kPreviewDatasets = "ScientaImage;ScientaSpectrum;ImageAngleDistribution;ImageEnergyDistribution;Counts;SampleCurrent;"
+
+/// List of datasets that must be loaded to determine the axis scaling of a Scienta image
+strconstant kScientaScalingDatasets = "LensMode;ScientaChannelBegin;ScientaChannelEnd;ScientaSliceBegin;ScientaSliceEnd;"
+
+/// List of datasets that should be transposed upon loading
+strconstant kTransposedDatasets = "ScientaImage;"
+
 /// open a HDF5 file created by the PShell data acquisition program and prepare the data folder.
 ///
 /// the function opens a specified or interactively selected HDF5 file,
@@ -301,21 +310,25 @@ function /s psh5_load_preview(ANickName, APathName, AFileName, [load_data, load_
 			endif
 			sg = StringFromList(ig, scanpaths)
 			dataname = psh5_load_scan_preview(fileID, sg, set_scale=load_attr, pref_datasets=pref_datasets)
-		endif
 
-		wave /z data = $dataname
+			wave /z data = $dataname
-		string destpath = GetDataFolder(1, saveDF) + ANickName
+			string destpath = GetDataFolder(1, saveDF) + ANickName
-		if (waveexists(data))
+			if (waveexists(data))
-			duplicate /o data, $destpath
+				duplicate /o data, $destpath
-			wave /z data = $destpath
+				wave /z data = $destpath
-		endif
+			else
-			
+				print "no data found in file " + AFileName
-		if (load_attr)
+			endif
-			setdatafolder saveDF
+
-			newdatafolder /o/s attr
+			if (load_attr)
-			killwaves /a/z
+				setdatafolder saveDF
-			psh5_load_scan_attrs(fileID, sg)
+				newdatafolder /o/s attr
-			setdatafolder ::
+				killwaves /a/z
+				psh5_load_scan_attrs(fileID, sg)
+				setdatafolder ::
+			endif
+		else
+			print "no scans found in file " + AFileName
 		endif
 
 		HDF5CloseFile fileID
@@ -510,17 +523,21 @@ function /s psh5_load_scan_attrs(fileID, scanpath, [attr_sets])
 		endif
 	endif
 	
+	variable ids
+	variable nds
+	string sds
+
 	if (attr_sets & 2)
-		attr_list = AddListItem("LensMode", attr_list, ";", inf)
+		nds = ItemsInList(kScientaScalingDatasets, ";")
-		attr_list = AddListItem("ScientaChannelBegin", attr_list, ";", inf)
+		for (ids = 0; ids < nds; ids += 1)
-		attr_list = AddListItem("ScientaChannelEnd", attr_list, ";", inf)
+			sds = StringFromList(ids, kScientaScalingDatasets)
-		attr_list = AddListItem("ScientaSliceBegin", attr_list, ";", inf)
+			if (WhichListItem(sds, attr_list) < 0)
-		attr_list = AddListItem("ScientaSliceEnd", attr_list, ";", inf)
+				attr_list = AddListItem(sds, attr_list, ";", inf)
+			endif
+		endfor
 	endif
 
-	variable ids
+	nds = ItemsInList(attr_list, ";")
-	variable nds = ItemsInList(attr_list, ";")
-	string sds
 	string wavenames = ""
 	for (ids = 0; ids < nds; ids += 1)
 		sds = StringFromList(ids, attr_list, ";")
@@ -529,6 +546,7 @@ function /s psh5_load_scan_attrs(fileID, scanpath, [attr_sets])
 			wavenames = AddListItem(s_wavenames, wavenames, ";", inf)
 		endif
 	endfor
+	wavenames = ReplaceString(";;", wavenames, ";")
 	
 	return wavenames
 end
@@ -695,7 +713,7 @@ function /s psh5_load_scan_preview(fileID, scanpath, [set_scale, pref_datasets])
 		set_scale = 1
 	endif
 	if (ParamIsDefault(pref_datasets) || (strlen(pref_datasets) == 0))
-		pref_datasets = "ScientaImage;ScientaSpectrum;ImageAngleDistribution;ImageEnergyDistribution;Counts;SampleCurrent"
+		pref_datasets = kPreviewDatasets
 	endif
 
 	dfref saveDF = GetDataFolderDFR()
@@ -880,9 +898,6 @@ end
 ///
 /// @return	name of loaded wave if successful. empty string otherwise.
 ///
-/// @todo	images are transposed in the first two dimensions.
-///			this is useful for Scienta images but may not be appropriate for other sources.
-///
 function /s psh5_load_dataset_slabs(fileID, datapath, datasetname, [progress])
 	variable fileID
 	string datapath
@@ -910,11 +925,19 @@ function /s psh5_load_dataset_slabs(fileID, datapath, datasetname, [progress])
 	if (di.ndims < 2)
 		print "error: rank of dataset < 2"
 		return ""
+	elseif (di.ndims < 3)
+		progress = 0
 	endif
 	
 	variable idx, idy, idz, idt, izt
-	idx = 1
+	variable transpose = WhichListItem(datawavename, kTransposedDatasets) >= 0
-	idy = 0
+	if (transpose)
+		idx = 1
+		idy = 0
+	else
+		idx = 0
+		idy = 1
+	endif
 	idz = 2
 	idt = 3
 	
@@ -951,7 +974,11 @@ function /s psh5_load_dataset_slabs(fileID, datapath, datasetname, [progress])
 			slab[idt][%Start] = it
 			HDF5LoadData /O /Q /Z /SLAB=slab /N=slabdata fileID, datasetpath
 			wave slabdata // 2D, 3D, or 4D with singletons
-			data[][][iz][it] = slabdata[q][p][0][0]
+			if (transpose)
+				data[][][iz][it] = slabdata[q][p][0][0]
+			else
+				data[][][iz][it] = slabdata[p][q][0][0]
+			endif
 			
 			// progress window
 			izt += 1
@@ -1007,9 +1034,6 @@ end
 ///
 /// @return					name of loaded wave if successful. empty string otherwise.
 ///
-/// @todo	images are transposed in the first two dimensions.
-///			this is useful for Scienta images but may not be appropriate for other data sources.
-///
 function /s psh5_load_dataset_slab(fileID, datapath, datasetname, dim2start, dim2count, dim3start, dim3count)
 	variable fileID
 	string datapath
@@ -1038,8 +1062,14 @@ function /s psh5_load_dataset_slab(fileID, datapath, datasetname, dim2start, dim
 	endif
 	
 	variable idx, idy, idz, idt
-	idx = 1
+	variable transpose = WhichListItem(datawavename, kTransposedDatasets) >= 0
-	idy = 0
+	if (transpose)
+		idx = 1
+		idy = 0
+	else
+		idx = 0
+		idy = 1
+	endif
 	idz = 2
 	idt = 3
 
@@ -1070,7 +1100,11 @@ function /s psh5_load_dataset_slab(fileID, datapath, datasetname, dim2start, dim
 			HDF5LoadData /O /Q /Z /SLAB=slab /N=slabdata fileID, datasetpath
 			if (!v_flag)
 				wave slabdata
-				data += slabdata[q][p][0][0]
+				if (transpose)
+					data += slabdata[q][p][0][0]
+				else
+					data += slabdata[p][q][0][0]
+				endif
 				navg += 1
 			endif
 		endfor
@@ -1570,11 +1604,19 @@ function /s psh5_load_dataset_reduced(fileID, scanpath, datasetname, reduction_f
 		print "error: rank of dataset < 2"
 		result = -2
 		return wavenames
+	elseif (di.ndims < 3)
+		progress = 0
 	endif
 	
 	variable idx, idy, idz, idt
-	idx = 1
+	variable transpose = WhichListItem(datawavename, kTransposedDatasets) >= 0
-	idy = 0
+	if (transpose)
+		idx = 1
+		idy = 0
+	else
+		idx = 0
+		idy = 1
+	endif
 	idz = 2
 	idt = 3