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R11173/v2p5/TDMS_readFileHelper_v1.m
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TDMS_readFileHelper_v1.m
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function data = TDMS_readFileHelper_v1(fid,optionStruct,metaStruct,paramsStruct)
%TDMS_readFileHelper_v1
%
%
% Time stamps in TDMS are stored as a structure of two components:
% (i64) seconds: since the epoch 01/01/1904 00:00:00.00 UTC (using the Gregorian calendar and ignoring leap seconds)
% (u64) positive fractions: (2^-64) of a second
% Boolean values are stored as 1 byte each, where 1 represents TRUE and 0 represents FALSE.
SECONDS_IN_DAY = paramsStruct.SECONDS_IN_DAY;
CONV_FACTOR = paramsStruct.CONV_FACTOR;
UTC_DIFF = paramsStruct.UTC_DIFF;
STRING_ENCODING = paramsStruct.STRING_ENCODING;
%INPUT UNPACKING
%==========================================================================
keepDataArray = optionStruct.keepDataArray;
numValuesToGetActual = optionStruct.numValuesToGetActual;
rawDataInfo = metaStruct.rawDataInfo;
segInfo = metaStruct.segInfo;
numberDataPoints = metaStruct.numberDataPoints;
numObjects = length(rawDataInfo);
numSegs = length(segInfo);
%INITIALIZATION OF OBJECTS
%==========================================================================
curFileIndex = zeros(1,numObjects); %current # of samples read from file
curDataIndex = zeros(1,numObjects); %current # of samples assigned to output
data = cell(1,numObjects); %a pointer for each channel
dataTypeArray = [rawDataInfo.dataType];
propNames = cell(1,numObjects);
propValues = cell(1,numObjects);
for iObject = 1:numObjects
propNames{iObject} = rawDataInfo(iObject).propNames;
propValues{iObject} = rawDataInfo(iObject).propValues;
if numberDataPoints(iObject) > 0 && keepDataArray(iObject)
data{iObject} = TDMS_initData(dataTypeArray(iObject),numberDataPoints(iObject));
end
end
%==================================================================
% RAW DATA PROCESSSING
%==================================================================
%This will be used later for fread and fseek
%Simplifies the switch statements
[precisionType, nBytes] = TDMS_getTypeSeekSizes;
%Get end of file position, seek back to beginning
fseek(fid,0,1);
eofPosition = ftell(fid);
fseek(fid,0,-1);
for iSeg = 1:numSegs
curSeg = segInfo(iSeg);
%Seek to this raw position, this is needed to avoid meta data
fseek(fid,curSeg.rawPos,'bof');
nChunksUse = curSeg.nChunks;
for iChunk = 1:nChunksUse
%------------------------------------------------------------------
%Interleaved data processing
%------------------------------------------------------------------
if curSeg.isInterleaved
objOrder = curSeg.objOrder;
dataTypes = dataTypeArray(objOrder);
nRead = curSeg.nSamplesRead;
%error checking
if any(dataTypes ~= dataTypes(1))
error('Interleaved data is assumed to be all of the same type')
end
if any(nRead ~= nRead(1))
error('# of values to read are not all the same')
end
%NOTE: unlike below, these are arrays that we are working with
startI = curFileIndex(objOrder) + 1;
endI = curFileIndex(objOrder) + nRead(1);
curFileIndex(objOrder) = endI;
curDataIndex(objOrder) = endI;
nChans = length(objOrder);
numValuesRead = nRead(1);
switch dataTypes(1)
case {1 2 3 4 5 6 7 8 9 10}
temp = fread(fid,numValuesRead*nChans,precisionType{dataTypes(1)});
case 32
error('Unexpected interleaved string data')
%In Labview 2009, the interleaved input is ignored
%Not sure about other versions
case 33
%This never seems to be called, shows up as uint8 :/
temp = logical(fread(fid,numValuesRead*nChans,'uint8'));
case 68
temp = fread(fid,numValuesRead*2*nChans,'*uint64');
temp = (double(temp(1:2:end))/2^64 + double(typecast(temp(2:2:end),'int64')))...
/SECONDS_IN_DAY + CONV_FACTOR + UTC_DIFF/24;
otherwise
error('Unexpected data type: %d',dataTypes(1))
end
%NOTE: When reshaping for interleaved, we must put nChans as
%the rows, as that is the major indexing direction, we then
%grab across columns
%Channel 1 2 3 1 2 3
%Data 1 2 3 11 22 33 becomes:
% 1 11
% 2 22 We can now grab rows to get individual channels
% 3 33
temp = reshape(temp,[nChans numValuesRead]);
for iChan = 1:nChans
if keepDataArray(objOrder(iChan))
data{objOrder(iChan)}(startI(iChan):endI(iChan)) = temp(iChan,:);
end
end
else
%--------------------------------------------------------------
%NOT INTERLEAVED
%--------------------------------------------------------------
for iObjList = 1:length(curSeg.objOrder);
I_object = curSeg.objOrder(iObjList);
numValuesAvailable = curSeg.nSamplesRead(iObjList);
dataType = dataTypeArray(I_object);
curFileIndex(I_object) = curFileIndex(I_object) + numValuesAvailable;
%Actual reading of data (or seeking past)
%------------------------------------------
if ~keepDataArray(I_object);
fseek(fid,numValuesAvailable*nBytes(dataType),'cof');
else
startI = curDataIndex(I_object) + 1;
endI = curDataIndex(I_object) + numValuesAvailable;
curDataIndex(I_object) = endI;
switch dataType
case {1 2 3 4 5 6 7 8 9 10}
data{I_object}(startI:endI) = fread(fid,numValuesAvailable,precisionType{dataType});
case 32
%Done above now ...
strOffsetArray = [0; fread(fid,numValuesAvailable,'uint32')];
offsetString = startI - 1;
for iString = 1:numValuesAvailable
offsetString = offsetString + 1;
temp = fread(fid,strOffsetArray(iString+1)-strOffsetArray(iString),'*uint8');
data{I_object}{offsetString} = native2unicode(temp,STRING_ENCODING)'; %#ok<*N2UNI>
end
%NOTE: Even when using a subset, we
%will only ever have one valid read
case 33
data{I_object}(startI:endI) = logical(fread(fid,numValuesAvailable,'uint8'));
case 68
temp = fread(fid,numValuesAvailable*2,'*uint64');
%First row: conversion to seconds
%Second row: conversion to days, and changing of reference frame
data{I_object}(startI:endI) = (double(temp(1:2:end))/2^64 + double(typecast(temp(2:2:end),'int64')))...
/SECONDS_IN_DAY + CONV_FACTOR + UTC_DIFF/24;
otherwise
error('Unexpected type: %d', dataType)
end
end
end
end
end
%Some error checking just in case
if iSeg ~= numSegs
Ttag = fread(fid,1,'uint8');
Dtag = fread(fid,1,'uint8');
Stag = fread(fid,1,'uint8');
mtag = fread(fid,1,'uint8');
if ~(Ttag == 84 && Dtag == 68 && Stag == 83 && mtag == 109)
error('Catastrophic error detected, code probably has an error somewhere')
end
else
if eofPosition ~= ftell(fid) && ~metaStruct.eof_error
error('Catastrophic error detected, code probably has an error somewhere')
end
end
end
%ERROR CHECKING ON # OF VALUES READ
%==========================================================================
if ~isequal(numValuesToGetActual,curDataIndex)
error('The # of requested values does not equal the # of returned values, error in code likely')
end
%END OF READING RAW DATA
%==========================================================================
fclose(fid);
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