How can I import DIAdem measurement data into MATLAB?

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I have TDM files which contain measurements taken with National Instruments DIAdem software. I would like to import the data into MATLAB to visualize and post-process the data.

Accepted Answer

MathWorks Support Team
MathWorks Support Team on 20 Jul 2020
Edited: MathWorks Support Team on 20 Jul 2020
The ability to directly import DIAdem TDMATLAB files is not available in MATLAB.
To work around this issue, you can use the "loadlibrary" function as demonstrated in the following example from National Instruments™:
Reading TDM/TDMS Files with MathWorks, Inc. MATLAB® Software
You can also export the measurement data from DIAdem into MS Excel or as an ASCII-formatted text file, and then import the data into MATLAB. Note that MS Excel is limited to 2^16 (65,536) rows for older versions and 2^20 (1,048,576) rows for newer versions.
To import Excel data into MATLAB you can use the "xlsread" command. The best function to use depends on the format of the text file. Several possible options are "csvread", "dlmread" or "textscan".
For more information on each of these commands please execute one of the commands below at the MATLAB command prompt:
doc xlsread
doc csvread
doc dlmread
doc textscan

More Answers (1)

Omkar Salunke
Omkar Salunke on 29 Jul 2021
CurrDirectory = '...//'; % Path to current directory
fileNametdx = '.../utility/'; % Path to TDX file
%%
% Data type conversion
Dtype.eInt8Usi='int8';
Dtype.eInt16Usi='int16';
Dtype.eInt32Usi='int32';
Dtype.eInt64Usi='int64';
Dtype.eUInt8Usi='uint8';
Dtype.eUInt16Usi='uint16';
Dtype.eUInt32Usi='uint32';
Dtype.eUInt64Usi='uint64';
Dtype.eFloat32Usi='single';
Dtype.eFloat64Usi='double';
%% Read .tdx file Name
wb=waitbar(0,'Reading *.tdx Files');
fileNameTDM = strrep(fileNametdx,'.tdx','.TDM');
%% Read .TDM
tdm=xml2struct(fileNameTDM);
for i=1:numel(tdm.usi_colon_tdm.usi_colon_data.tdm_channel)
waitbar((1/numel(tdm.usi_colon_tdm.usi_colon_data.tdm_channel))*i,wb,['File ' fileNametdx ' conversion started']);
s1=strsplit(string(tdm.usi_colon_tdm.usi_colon_data.tdm_channel{1, i}.local_columns.Text),'"');
usi1=s1(2);
% if condition match untill we get usi2
for j=1:numel(tdm.usi_colon_tdm.usi_colon_data.localcolumn)
usi2=string(tdm.usi_colon_tdm.usi_colon_data.localcolumn{1, j}.Attributes.id);
if usi1==usi2
%take new usi
s2=strsplit(string(tdm.usi_colon_tdm.usi_colon_data.localcolumn{1, j}.values.Text),'"');
new_usi1=s2(2);
w1=strsplit(string(tdm.usi_colon_tdm.usi_colon_data.tdm_channel{1, i}.datatype.Text),'_');
str_1=char(strcat('tdm.usi_colon_tdm.usi_colon_data.',lower(w1(2)),'_sequence'));
str_2=char(strcat('tdm.usi_colon_tdm.usi_colon_data.',lower(w1(2)),'_sequence{1, k}.Attributes.id'));
str_3=char(strcat('tdm.usi_colon_tdm.usi_colon_data.',lower(w1(2)),'_sequence{1, k}.values.Attributes.external'));
str_4=char(strcat('tdm.usi_colon_tdm.usi_colon_data.',lower(w1(2)),'_sequence{1, k}.values'));
for k=1:numel(eval(str_1))
new_usi2=string(eval(str_2));
if new_usi1==new_usi2
if isfield(eval(str_4), 'Attributes')
inc_value1=string(eval(str_3));
for m=1:numel(tdm.usi_colon_tdm.usi_colon_include.file.block)
inc_value2=string(tdm.usi_colon_tdm.usi_colon_include.file.block{1, m}.Attributes.id);
if inc_value1==inc_value2
% offset=round(str2num(tdm.usi_colon_tdm.usi_colon_include.file.block{1, m}.Attributes.byteOffset)/8);
length = round(str2num(tdm.usi_colon_tdm.usi_colon_include.file.block{1, m}.Attributes.length));
offset1=round(str2num(tdm.usi_colon_tdm.usi_colon_include.file.block{1, m}.Attributes.byteOffset));
value_type = tdm.usi_colon_tdm.usi_colon_include.file.block{1, m}.Attributes.valueType;
m = memmapfile(fullfile(CurrDirectory,fileNametdx),'Offset',offset1,'Format',{Dtype.(value_type) [length 1] 'dat'},'Writable',true,'Repeat',1);
dat=m.Data.dat ;
end
end
else
str_5=char(strcat('tdm.usi_colon_tdm.usi_colon_data.',lower(w1(2)),'_sequence{1, k}.values.',char(fieldnames(tdm.usi_colon_tdm.usi_colon_data.string_sequence{1, k}.values))));
dat=eval(str_5)';
end
name_variable = string(tdm.usi_colon_tdm.usi_colon_data.tdm_channel{1, i}.name.Text);
varname = genvarname(char(name_variable));
variable.(varname) = dat;
end
end
end
end
end
waitbar(1,wb,[fileNametdx ' conversion completed']);
pause(1)
close(wb)
delete(fullfile(CurrDirectory,fileNametdx),fullfile(CurrDirectory,fileNameTDM));
%Output Variable is Struct
clearvars -except variable
This script requires following XML parser
function [ s ] = xml2struct( file )
%Convert xml file into a MATLAB structure
% [ s ] = xml2struct( file )
%
% A file containing:
% <XMLname attrib1="Some value">
% <Element>Some text</Element>
% <DifferentElement attrib2="2">Some more text</Element>
% <DifferentElement attrib3="2" attrib4="1">Even more text</DifferentElement>
% </XMLname>
%
% Will produce:
% s.XMLname.Attributes.attrib1 = "Some value";
% s.XMLname.Element.Text = "Some text";
% s.XMLname.DifferentElement{1}.Attributes.attrib2 = "2";
% s.XMLname.DifferentElement{1}.Text = "Some more text";
% s.XMLname.DifferentElement{2}.Attributes.attrib3 = "2";
% s.XMLname.DifferentElement{2}.Attributes.attrib4 = "1";
% s.XMLname.DifferentElement{2}.Text = "Even more text";
%
% Please note that the following characters are substituted
% '-' by '_dash_', ':' by '_colon_' and '.' by '_dot_'
%
% Written by W. Falkena, ASTI, TUDelft, 21-08-2010
% Attribute parsing speed increased by 40% by A. Wanner, 14-6-2011
% Added CDATA support by I. Smirnov, 20-3-2012
%
% Modified by X. Mo, University of Wisconsin, 12-5-2012
if (nargin < 1)
clc;
help xml2struct
return
end
if isa(file, 'org.apache.xerces.dom.DeferredDocumentImpl') || isa(file, 'org.apache.xerces.dom.DeferredElementImpl')
% input is a java xml object
xDoc = file;
else
%check for existance
if (exist(file,'file') == 0)
%Perhaps the xml extension was omitted from the file name. Add the
%extension and try again.
if (isempty(strfind(file,'.xml')))
file = [file '.xml'];
end
if (exist(file,'file') == 0)
error(['The file ' file ' could not be found']);
end
end
%read the xml file
xDoc = xmlread(file);
end
%parse xDoc into a MATLAB structure
s = parseChildNodes(xDoc);
end
% ----- Subfunction parseChildNodes -----
function [children,ptext,textflag] = parseChildNodes(theNode)
% Recurse over node children.
children = struct;
ptext = struct; textflag = 'Text';
if hasChildNodes(theNode)
childNodes = getChildNodes(theNode);
numChildNodes = getLength(childNodes);
for count = 1:numChildNodes
theChild = item(childNodes,count-1);
[text,name,attr,childs,textflag] = getNodeData(theChild);
if (~strcmp(name,'#text') && ~strcmp(name,'#comment') && ~strcmp(name,'#cdata_dash_section'))
%XML allows the same elements to be defined multiple times,
%put each in a different cell
if (isfield(children,name))
if (~iscell(children.(name)))
%put existsing element into cell format
children.(name) = {children.(name)};
end
index = length(children.(name))+1;
%add new element
children.(name){index} = childs;
if(~isempty(fieldnames(text)))
children.(name){index} = text;
end
if(~isempty(attr))
children.(name){index}.('Attributes') = attr;
end
else
%add previously unknown (new) element to the structure
children.(name) = childs;
if(~isempty(text) && ~isempty(fieldnames(text)))
children.(name) = text;
end
if(~isempty(attr))
children.(name).('Attributes') = attr;
end
end
else
ptextflag = 'Text';
if (strcmp(name, '#cdata_dash_section'))
ptextflag = 'CDATA';
elseif (strcmp(name, '#comment'))
ptextflag = 'Comment';
end
%this is the text in an element (i.e., the parentNode)
if (~isempty(regexprep(text.(textflag),'[\s]*','')))
if (~isfield(ptext,ptextflag) || isempty(ptext.(ptextflag)))
ptext.(ptextflag) = text.(textflag);
else
%what to do when element data is as follows:
%<element>Text <!--Comment--> More text</element>
%put the text in different cells:
% if (~iscell(ptext)) ptext = {ptext}; end
% ptext{length(ptext)+1} = text;
%just append the text
ptext.(ptextflag) = [ptext.(ptextflag) text.(textflag)];
end
end
end
end
end
end
% ----- Subfunction getNodeData -----
function [text,name,attr,childs,textflag] = getNodeData(theNode)
% Create structure of node info.
%make sure name is allowed as structure name
name = toCharArray(getNodeName(theNode))';
name = strrep(name, '-', '_dash_');
name = strrep(name, ':', '_colon_');
name = strrep(name, '.', '_dot_');
attr = parseAttributes(theNode);
if (isempty(fieldnames(attr)))
attr = [];
end
%parse child nodes
[childs,text,textflag] = parseChildNodes(theNode);
if (isempty(fieldnames(childs)) && isempty(fieldnames(text)))
%get the data of any childless nodes
% faster than if any(strcmp(methods(theNode), 'getData'))
% no need to try-catch (?)
% faster than text = char(getData(theNode));
text.(textflag) = toCharArray(getTextContent(theNode))';
end
end
% ----- Subfunction parseAttributes -----
function attributes = parseAttributes(theNode)
% Create attributes structure.
attributes = struct;
if hasAttributes(theNode)
theAttributes = getAttributes(theNode);
numAttributes = getLength(theAttributes);
for count = 1:numAttributes
%attrib = item(theAttributes,count-1);
%attr_name = regexprep(char(getName(attrib)),'[-:.]','_');
%attributes.(attr_name) = char(getValue(attrib));
%Suggestion of Adrian Wanner
str = toCharArray(toString(item(theAttributes,count-1)))';
k = strfind(str,'=');
attr_name = str(1:(k(1)-1));
attr_name = strrep(attr_name, '-', '_dash_');
attr_name = strrep(attr_name, ':', '_colon_');
attr_name = strrep(attr_name, '.', '_dot_');
attributes.(attr_name) = str((k(1)+2):(end-1));
end
end
end

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