MDF Import Function Help

This document describes how to import MDF files with mdfimport called as function. To learn how to call mdfimport as an interactive tool, see separate MDF import tool help.

Function parameters
File name
Import location
Signal selection
Time vector type
Rate designation
Additional text
Example: Import all signals from an MDF file to the workspace using defaults
Example: Import all signals to a MAT-file with automatic name
Example: Import all signals to a MAT-file with a specified name
Example: Import just two signals
Example: Import signals with names stored in signal selection text file
Example: Use rate string rather than rate number to designate variable rates
Example: Append variable names with additional text
Example: Import multiple MDF files using a for loop
Example: Import a whole directory of MDF files as store as MAT-Files

Function parameters

The mdfimport tool, when called as a function takes up to six parameters provided in this order:

mdfimport(fileName,importlocation,signalselection,timevectortype,ratedesignation, additionaltext);

All parameters are optional except for the first, the file name, which must be provided if mdfimport is to be called as a function. The list below shows the possible values of each parameter. Curly braces { } enclose default values. Use [] to skip parameters.

File name

fileName: 'MDFfilename.dat'

String specifying name of the MDF file to be imported. Must be provided if mdfimport is to be called as a function.

Import location

importlocation: {'workspace'} | 'Auto MAT-File' | 'MATfilename.mat'

String specifying location signals are to be imported to, which can be the base workspace ('workspace'), a MAT file with the same name as the MDF file ('Auto MAT-File') or a MAT file of specified name. Note that 'workspace' specifies the base workspace. As a result, mdfimport is not easily called from a function. A workaround is to save to a MAT-File then load back in.

Signal selection

signalselection: {'all'} | 'signalselectionfilename.txt' | cellarrayofnames

String or cell array specifying which signals to be selected, which can be all signals ('all'), those with names listed in a given signal selection file or in a cell array of strings.

Time vector type

timevectortype: {'actual'} | 'ideal'

String specifying what time instants to put in time vector, which can either be the actual times from the associated time signal in the MDF file ('actual') or ideal uniform sampled times ('ideal').

Rate designation

ratedesignation: {'ratenumber'} | 'ratestring'

String specifying how the rate of the variables is designated. Options are either an integer ('ratenumber'), e.g. rpm_1 , or a string representing the sample rate ('ratestring'), e.g. rmp_10ms

Additional text

|additionaltext: 'text'

String specifying optional additional text to append to names of all variables generated. This can be useful if you want to differentiate data from multiple sessions, simulation runs or experiments. The default is to have no additional text.

The follow section gives examples of using mdfimport called as a function.

Example: Import all signals from an MDF file to the workspace using defaults

clear;
mdfimport('BitSignals.dat');

Created 3 signal variable(s) appended with '_1' for 'TimeC' rate
... and 1 actual time vector 'time_1'

whos

  Name             Size                    Bytes  Class

  B_GREEN_1       50x1                       400  double array
  B_RED_1         50x1                       400  double array
  B_YELLOW_1      50x1                       400  double array
  time_1          50x1                       400  double array

Grand total is 200 elements using 1600 bytes

Example: Import all signals to a MAT-file with automatic name

clear
mdfimport('BitSignals.dat','Auto MAT-File');

Created 3 signal variable(s) appended with '_1' for 'TimeC' rate
... and 1 actual time vector 'time_1'

dir *.mat

BitSignals.mat  measure239.mat  my01.mat

whos('-file', 'BitSignals.mat')

  Name             Size                    Bytes  Class

  B_GREEN_1       50x1                       400  double array
  B_RED_1         50x1                       400  double array
  B_YELLOW_1      50x1                       400  double array
  time_1          50x1                       400  double array

Grand total is 200 elements using 1600 bytes

delete BitSignals.mat % clean up

Example: Import all signals to a MAT-file with a specified name

clear
mdfimport('BitSignals.dat','mymatfile.mat');

Created 3 signal variable(s) appended with '_1' for 'TimeC' rate
... and 1 actual time vector 'time_1'

dir *.mat

measure239.mat  my01.mat        mymatfile.mat

delete mymatfile.mat % clean up

Example: Import just two signals

clear
mdfimport('BitSignals.dat',[],{'B_GREEN' 'B_RED'});

Created 2 signal variable(s) appended with '_1' for 'TimeC' rate
... and 1 actual time vector 'time_1'

whos

  Name            Size                    Bytes  Class

  B_GREEN_1      50x1                       400  double array
  B_RED_1        50x1                       400  double array
  time_1         50x1                       400  double array

Grand total is 150 elements using 1200 bytes

Example: Import signals with names stored in signal selection text file

Show contents of signal selection file :

clear;
type signalselection.txt

58X3160
ACREQAI
ACREQ

mdfimport('DICP_V6_vehicle_data.dat',[],'signalselection.txt');

Created 2 signal variable(s) appended with '_3' for '7.82ms' rate
... and 1 actual time vector 'time_3'
Created 1 signal variable(s) appended with '_4' for 'Cyl Event' rate
... and 1 actual time vector 'time_4'

whos

  Name             Size                    Bytes  Class

  ACREQAI_3    78533x1                    628264  double array
  ACREQ_3      78533x1                    628264  double array
  time_3       78533x1                    628264  double array
  time_4       46362x1                    370896  double array
  x58X3160_4   46362x1                    370896  double array

Grand total is 328323 elements using 2626584 bytes

Example: Use rate string rather than rate number to designate variable rates

clear;
mdfimport('DICP_V6_vehicle_data.dat',[],'signalselection.txt',[],'ratestring');

Created 2 signal variable(s) appended with '_7p82ms' for '7.82ms' rate
... and 1 actual time vector 'time_7p82ms'
Created 1 signal variable(s) appended with '_Cyl_Event' for 'Cyl Event' rate
... and 1 actual time vector 'time_Cyl_Event'

whos

  Name                     Size                    Bytes  Class

  ACREQAI_7p82ms       78533x1                    628264  double array
  ACREQ_7p82ms         78533x1                    628264  double array
  time_7p82ms          78533x1                    628264  double array
  time_Cyl_Event       46362x1                    370896  double array
  x58X3160_Cyl_Event   46362x1                    370896  double array

Grand total is 328323 elements using 2626584 bytes

Example: Append variable names with additional text

clear;
mdfimport('BitSignals.dat',[],[],[],[],'_run1');
mdfimport('BitSignals.dat',[],[],[],[],'_run2');

Created 3 signal variable(s) appended with '_1_run1' for 'TimeC' rate
... and 1 actual time vector 'time_1_run1'
Created 3 signal variable(s) appended with '_1_run2' for 'TimeC' rate
... and 1 actual time vector 'time_1_run2'

whos

  Name                  Size                    Bytes  Class

  B_GREEN_1_run1       50x1                       400  double array
  B_GREEN_1_run2       50x1                       400  double array
  B_RED_1_run1         50x1                       400  double array
  B_RED_1_run2         50x1                       400  double array
  B_YELLOW_1_run1      50x1                       400  double array
  B_YELLOW_1_run2      50x1                       400  double array
  time_1_run1          50x1                       400  double array
  time_1_run2          50x1                       400  double array

Grand total is 400 elements using 3200 bytes

Example: Import multiple MDF files using a for loop

clear;

% Specify list of file names as cell array of strings
MDFFileNames={'BitSignals.dat' 'my01.dat' 'measure239.dat'};

for k=1:length(MDFFileNames)
    % Remember to use {} to access string in cell array
    mdfimport(MDFFileNames{k},'Auto MAT-File');  % Call mdfimport
end

Created 3 signal variable(s) appended with '_1' for 'TimeC' rate
... and 1 actual time vector 'time_1'
Created 1 signal variable(s) appended with '_1' for '1.0ms' rate
... and 1 actual time vector 'time_1'
Created 1 signal variable(s) appended with '_1' for '2ms' rate
... and 1 actual time vector 'time_1'

Note: From R14SP3 on, this can be done in one line with:

cellfun(@(x) mdfimport(x, 'Auto MAT-File'), MDFFileNames);

Show generated MAT files:

dir *.mat

BitSignals.mat  measure239.mat  my01.mat

Example: Import a whole directory of MDF files as store as MAT-Files

clear

View names of MDF files in a directory

dir *.dat

BitSignals.dat  measure239.dat  my01.dat

Import files

% Get info on MDF files
MDFFilesInfo = dir('*.dat');

% Load all and convert to .mat
for k=1:length(MDFFilesInfo)
    mdfimport(MDFFilesInfo(k).name,'Auto MAT-File');  % Call mdfimport
end

Created 3 signal variable(s) appended with '_1' for 'TimeC' rate
... and 1 actual time vector 'time_1'
Created 1 signal variable(s) appended with '_1' for '2ms' rate
... and 1 actual time vector 'time_1'
Created 1 signal variable(s) appended with '_1' for '1.0ms' rate
... and 1 actual time vector 'time_1'