diff --git a/opensource/PlotPseudorangeRates.m b/opensource/PlotPseudorangeRates.m
index c052868..85ec601 100644
--- a/opensource/PlotPseudorangeRates.m
+++ b/opensource/PlotPseudorangeRates.m
@@ -60,8 +60,11 @@ for i=1:M
             else
                 colors(i,:) = get(h,'Color');
             end
-           text(ti,y(iFi(end)-1),int2str(gnssMeas.Svid(i)),'Color',colors(i,:));
-           meanDprM = mean(y(isfinite(y)));%store for analysing delta prr dpr
+            iFi = find(isfinite(y));
+            if any(iFi)
+                text(ti,y(iFi(end)),int2str(gnssMeas.Svid(i)),'Color',colors(i,:));
+            end
+           meanDprM = mean(y(iFi));%store for analysing delta prr dpr
            deltaMeanM(i) = meanPrrM - meanDprM;
         end
     end
diff --git a/opensource/PlotPvt.m b/opensource/PlotPvt.m
index 691b0ee..7ac7886 100644
--- a/opensource/PlotPvt.m
+++ b/opensource/PlotPvt.m
@@ -25,17 +25,18 @@ iFi = isfinite(gpsPvt.allLlaDegDegM(:,1));%index into finite results
 if ~any(iFi)
     return
 end
-llaMed = median(gpsPvt.allLlaDegDegM(iFi,:));%use median position as reference
+llaMed = median(gpsPvt.allLlaDegDegM(iFi,:));%median position
+%print median lla so user can use it as reference position if they want:
+fprintf('Median llaDegDegM = [%.7f %.7f %.2f]\n',llaMed)
+
 if nargin < 3, llaTrueDegDegM = []; end
-if nargin < 4. titleString = 'PVT solution'; end
+if nargin < 4, titleString = 'PVT solution'; end
 bGotLlaTrue = ~isempty(llaTrueDegDegM) && any(llaTrueDegDegM);
 %not empty and not all zeros
 if bGotLlaTrue
     llaRef = llaTrueDegDegM;
 else
     llaRef = llaMed;
-    %print median lla so user can use it as reference position if they want
-    fprintf('Median llaDegDegM = [%.7f %.7f %.2f]\n',llaMed)
 end
 
 %% plot ne errors vs llaTrueDegDegM --------------------------------------------
diff --git a/opensource/ProcessGnssMeasScript.m b/opensource/ProcessGnssMeasScript.m
index 1bae34a..410ac78 100644
--- a/opensource/ProcessGnssMeasScript.m
+++ b/opensource/ProcessGnssMeasScript.m
@@ -28,7 +28,7 @@ param.llaTrueDegDegM = [37.422578, -122.081678, -28];%Charleston Park Test Site
 
 %% Set the data filter and Read log file
 dataFilter = SetDataFilter;
-[gnssRaw,gnssAnalysis] = ReadGnssLogger(dirName,prFileName,dataFilter,param);
+[gnssRaw,gnssAnalysis] = ReadGnssLogger(dirName,prFileName,dataFilter);
 if isempty(gnssRaw), return, end
 
 %% Get online ephemeris from Nasa ftp, first compute UTC Time from gnssRaw:
diff --git a/opensource/ReadGnssLogger.m b/opensource/ReadGnssLogger.m
index d90735d..ec9f2a4 100644
--- a/opensource/ReadGnssLogger.m
+++ b/opensource/ReadGnssLogger.m
@@ -1,5 +1,5 @@
 function [gnssRaw,gnssAnalysis] = ReadGnssLogger(dirName,fileName,dataFilter,gnssAnalysis)
-%% [gnssRaw,gnssAnalysis]=ReadGnssLogger(dirName,fileName,dataFilter,gnssAnalysis);
+%% [gnssRaw,gnssAnalysis]=ReadGnssLogger(dirName,fileName,[dataFilter],[gnssAnalysis]);
 % Read the log file created by Gnss Logger App in Android
 % Compatible with Android release N
 %
@@ -7,12 +7,14 @@ function [gnssRaw,gnssAnalysis] = ReadGnssLogger(dirName,fileName,dataFilter,gns
 %  dirName = string with directory of fileName, 
 %                e.g. '~/Documents/MATLAB/Pseudoranges/2016-03-28'
 %  fileName = string with filename
-%  dataFilter = nx2 cell array of pairs of strings, 
+%  optional inputs:
+%  [dataFilter], nx2 cell array of pairs of strings, 
 %      dataFilter{i,1} is a string with one of 'Raw' header values from the 
 %                      GnssLogger log file e.g. 'ConstellationType'
 %      dataFilter{i,2} is a string with a valid matlab expression, containing
 %                      the header value, e.g. 'ConstellationType==1'
-%  See SetDataFilter.m for full rules and examples of dataFilter.
+%      See SetDataFilter.m for full rules and examples of dataFilter.
+%  [gnssAnalysis] structure containing analysis, incl list of missing fields
 %
 % Output: 
 %  gnssRaw, all GnssClock and GnssMeasurement fields from log file, including:
@@ -45,6 +47,7 @@ function [gnssRaw,gnssAnalysis] = ReadGnssLogger(dirName,fileName,dataFilter,gns
 % ReportMissingFields()
 
 %% Initialize outputs and inputs
+gnssRaw = [];
 gnssAnalysis.GnssClockErrors = 'GnssClock Errors.';
 gnssAnalysis.GnssMeasurementErrors = 'GnssMeasurement Errors.';
 gnssAnalysis.ApiPassFail = '';
@@ -63,7 +66,8 @@ rawCsvFile = MakeCsv(dirName,fileName);
 %% apply dataFilter 
 [bOk] = CheckDataFilter(dataFilter,header);
 if ~bOk, return, end
-C = FilterData(C,dataFilter,header);
+[bOk,C] = FilterData(C,dataFilter,header);
+if ~bOk, return, end
 
 %% pack data into gnssRaw structure
 [gnssRaw,missing] = PackGnssRaw(C,header);
@@ -130,7 +134,9 @@ end
 if isempty(strfind(sPlatform,'N'))
     %add || strfind(platform,'O') and so on for future platforms
     fprintf('\nThis version of ReadGnssLogger supports Android N\n')
-    error('Found "%s" in log file, expected "Platform: N"',line)
+    fprintf('WARNING: did not find "Platform" type in log file, expected "Platform: N"\n')
+    fprintf('Please Update GnssLogger\n')
+    sPlatform = 'N';%assume version N
 end
 
 v1 = [1;4;0;0];
@@ -237,9 +243,10 @@ fclose(fid);
 end% of function ReadRawCsv
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
-function C = FilterData(C,dataFilter,header)
+function [bOk,C] = FilterData(C,dataFilter,header)
 %% filter C based on contents of dataFilter
 
+bOk = true;
 iS = ones(size(C{1})); %initialize index into rows of C
 for i=1:size(dataFilter,1)
     j=find(strcmp(header,dataFilter{i,1}));%j = index into header
@@ -262,6 +269,8 @@ end
 if ~any(iS) %if all zeros
     fprintf('\nAll measurements removed. Specify dataFilter less strictly than this:, ')
     dataFilter(:,2)
+    bOk=false;
+    C=[];
     return
 end
 
diff --git a/opensource/SetDataFilter.m b/opensource/SetDataFilter.m
index eb60f33..98f45f2 100644
--- a/opensource/SetDataFilter.m
+++ b/opensource/SetDataFilter.m
@@ -8,13 +8,9 @@ function dataFilter = SetDataFilter
 %Author: Frank van Diggelen
 %Open Source code for processing Android GNSS Measurements
 
-%filter for fine time measurements only  <=> uncertainty < 10 ms = 1e7 ns
-dataFilter{1,1} = 'BiasUncertaintyNanos'; 
-dataFilter{1,2} = 'BiasUncertaintyNanos < 1e7'; 
-
 %filter out FullBiasNanos == 0
-dataFilter{end+1,1} = 'FullBiasNanos'; 
-dataFilter{end,2}   = 'FullBiasNanos ~= 0'; 
+dataFilter{1,1} = 'FullBiasNanos'; 
+dataFilter{1,2}   = 'FullBiasNanos ~= 0'; 
 
 %you can create other filters in the same way ...
 %for example, suppose you want to remove Svid 23:
@@ -26,6 +22,11 @@ dataFilter{end,2}   = 'FullBiasNanos ~= 0';
 % NOTE: you *cannot* use 'any(Svid)==[2,5,10,17]' because Svid refers to a 
 % vector variable and you must compare it to a scalar.
 
+%filter for fine time measurements only  <=> uncertainty < 10 ms = 1e7 ns
+%For Nexus 5x and 6p this field is not filled, so comment out these next 2 lines
+% dataFilter{end+1,1} = 'BiasUncertaintyNanos'; 
+% dataFilter{end,2} = 'BiasUncertaintyNanos < 1e7'; 
+
 %keep only Svid 2
 % dataFilter{end+1,1} = 'Svid'; 
 % dataFilter{end,2}   = 'Svid==2';