--- a/macros.xml	Thu Sep 24 11:43:31 2020 +0000
+++ b/macros.xml	Sun Sep 27 11:10:30 2020 +0000
@@ -117,6 +117,13 @@
     <token name="@DATA_PROPERTIES_INRAM@"><![CDATA[ 
 ########################### QC numbers ########################
 ## including intensity calculations which need data in RAM
+
+	int_matrix = as.matrix(spectra(msidata)) ## only load once into RAM, then re-use
+	## Number of NA in spectra matrix
+        NAcount = sum(is.na(int_matrix))
+	## replace NA with zero to calculate data properties based on intensity matrix, no change in msidata
+	int_matrix[is.na(int_matrix)] <- 0
+	
         ## Number of features (mz)
         maxfeatures = length(features(msidata))
         ## Range mz
@@ -131,14 +138,12 @@
         minimumy = min(coord(msidata)[,2])
         maximumy = max(coord(msidata)[,2])
         ## Range of intensities
-        minint = round(min(as.matrix(spectra(msidata)), na.rm=TRUE), digits=2)
-        maxint = round(max(as.matrix(spectra(msidata)), na.rm=TRUE), digits=2)
+        minint = round(min(int_matrix), digits=2)
+        maxint = round(max(int_matrix), digits=2)
         ## Number of intensities > 0, for if conditions
-        npeaks= sum(as.matrix(spectra(msidata))>0, na.rm=TRUE)
+        npeaks= sum(int_matrix>0)
         ## Number of NA in spectra matrix
-        NAcount = sum(is.na(spectra(msidata)))
-        ## Number of NA in spectra matrix
-        infcount = sum(is.infinite(as.matrix(spectra(msidata))))
+        infcount = sum(is.infinite(int_matrix))
         ## Number of duplicated coordinates
         dupl_coord = sum(duplicated(coord(msidata)))
         properties = c("Number of m/z features",