I wanna make a .mat file

Hi, how can I comprise of a .mat file for my data. THank you.

[Walter Roberson]

Do you want to do this in MATLAB, or in Python, or in R, or in C or C++, or in Fortran?

[MERVE]

matlab :)

[Image Analyst]

Did you see my answer below? Scroll down.

[Merve ozdas]

eeg=csvread("eeg.csv");

save('eeg_file.mat','eeg')% this 'eeg' is from variable that I defined.

[Image Analyst]

Yes, that will work. And like I showed in my answer, you can simply list all the variables after that if you want any additional variables changed. So if it's working for you, you can click the "Accept this answer" for my answer or one you think is better than mine.

Answer 1

[John D'Errico]

help save

 SAVE Save workspace variables to file. 
    SAVE(FILENAME) stores all variables from the current workspace in a
    MATLAB formatted binary file (MAT-file) called FILENAME. Specify 
    FILENAME as a character vector or a string scalar. For example, specify
    FILENAME as 'myFile.mat' or "myFile.mat".
 
    SAVE(FILENAME,VARIABLES) stores only the specified variables. Specify 
    FILENAME and VARIABLES as character vectors or string scalars.
 
    SAVE(FILENAME,'-struct',STRUCTNAME,FIELDNAMES) stores the fields of the
    specified scalar structure as individual variables in the file. If you 
    include the optional FIELDNAMES, the SAVE function stores only the
    specified fields of the structure.  You cannot specify VARIABLES and 
    the '-struct' keyword in the same call to SAVE.
 
    SAVE(FILENAME, ..., '-append') adds new variables to an existing file.
    You can specify '-append' with additional inputs such as VARIABLES,
    '-struct', FORMAT, or VERSION.
 
    SAVE(FILENAME, ..., FORMAT) saves in the specified format: '-mat' or
    '-ascii'.
    You can specify FORMAT with additional inputs such as VARIABLES,
    '-struct', '-append', or VERSION.
 
    SAVE(FILENAME, ..., VERSION) saves to MAT-files in the specified
    version: '-v4', '-v6', '-v7', or '-v7.3'.
    You can specify VERSION with additional inputs such as VARIABLES,
    '-struct', '-append', '-nocompression', or FORMAT.
 
    SAVE(FILENAME, ..., '-nocompression', '-v7.3') saves to MAT-files version 7.3
    without compression.
    You can specify '-nocompression' with additional inputs such as VARIABLES and
    '-append'. This option is supported for MAT-files version 7 and above.
 
    SAVE FILENAME ... is the command form of the syntax, for convenient 
    saving from the command line.  With command syntax, you do not need to
    enclose FILENAME in single or double quotation marks.  Separate inputs 
    with spaces instead of commas.  Do not use command syntax if inputs 
    such as FILENAME are variables.
 
    Inputs:
 
    FILENAME: If you do not specify FILENAME, the SAVE function saves to a
    file named matlab.mat.  If FILENAME does not include an extension and 
    the value of format is '-mat' (the default), MATLAB appends .mat. If 
    filename does not include a full path, MATLAB saves in the current
    folder. You must have permission to write to the file.
 
    VARIABLES:  Save only selected variables from the workspace.
    Use one of the following forms:
 
        V1, V2, ...              Save the listed variables. Use the '*'
                                 wildcard to match patterns.  For example,
                                 save('A*') saves all variables that start
                                 with A.
        '-regexp', EXPRESSIONS   Save only the variables that match the
                                 specified regular expressions. SAVE treats
                                 all inputs as regular expressions except
                                 the optional FILENAME and STRUCTNAME.  The
                                 FILENAME input must appear first.  For
                                 more information on regular expressions,
                                 type "doc regexp" at the command prompt.
 
    '-struct', STRUCTNAME, FIELDNAMES:  Save the fields of a scalar
    structure as individual variables in the file.  FIELDNAMES is optional; 
    specify to save only selected fields.  FIELDNAMES use the same forms as
    VARIABLES.
 
    '-append': Add data to an existing file.  For MAT-files, '-append' adds
    new variables to the file or replaces the saved values of existing
    variables with values in the workspace.  For ASCII files, '-append'
    adds data to the end of the file.
 
    FORMAT: Specify the format of the file, regardless of any specified
    extension.  Use one of the following combinations:
 
        '-mat'                        Binary MAT-file format (default).
        '-ascii'                      8-digit ASCII format.
        '-ascii', '-tabs'             Tab-delimited 8-digit ASCII format.
        '-ascii', '-double'           16-digit ASCII format.
        '-ascii', '-double', '-tabs'  Tab-delimited 16-digit ASCII format.
 
        For ASCII file formats, the SAVE function has the following
        limitations:
        * Each variable must be a two-dimensional double or char array.
        * MATLAB translates characters to their corresponding internal
          ASCII codes.  For example, 'abc' appears in an ASCII file as:
              9.7000000e+001  9.8000000e+001  9.9000000e+001
        * The output includes only the real component of complex numbers.
        * If you plan to use the LOAD function to read the file, all
          variables must have the same number of columns.
 
    '-nocompression': Save data to a MAT-file without compression. The
    '-nocompression' option is only supported for MAT-files version 7 and above.
 
    VERSION: Create a MAT-file that you can load into an earlier version of
    MATLAB or that supports specific features.  The following table shows 
    the available MAT-file version options and the corresponding supported
    features.
 
             | Can Load in  |
    Option   | Versions     | Supported Features
    ---------+--------------+----------------------------------------------
    '-v7.3'  | 7.3 or later | Version 7.0 features plus support for
             |              | data items greater than or equal to 2GB on
             |              | 64-bit systems.
    ---------+--------------+----------------------------------------------
    '-v7'    | 7.0 or later | Version 6 features plus data compression and
             |              | Unicode character encoding. Saving variables
             |              | without compression is also supported using 
             |              | the '-nocompression' flag.
    ---------+--------------+----------------------------------------------
    '-v6'    | 5 or later   | Version 4 features plus N-dimensional arrays,
             |              | cell and structure arrays, and variable names
             |              | greater than 19 characters
    ---------+--------------+----------------------------------------------
    '-v4'    | all          | Two-dimensional double, character, and
             |              | sparse arrays
 
    If any data items require features that the specified version does not
    support, MATLAB does not save those items and issues a warning. You 
    cannot specify a version later than your version of MATLAB software.
 
    To view or set the default version for MAT-files, select
    File > Preferences > General > MAT-Files.
 
    Examples:
 
    % Save all variables from the workspace to test.mat:
    save test.mat
 
    % Save two variables, where FILENAME is a variable:
    savefile = 'pqfile.mat';
    p = rand(1, 10);
    q = ones(10);
    save(savefile, 'p', 'q');
 
    % Save the fields of a structure as individual variables:
    s1.a = 12.7;
    s1.b = {'abc', [4 5; 6 7]};
    s1.c = 'Hello!';
    save('newstruct.mat', '-struct', 's1');
 
    % Save variables whose names contain digits:
    save myfile.mat -regexp \d
 
    See also LOAD, MATFILE, WHOS, REGEXP, HGSAVE, SAVEAS, WORKSPACE, CLEAR.

    Documentation for save
       doc save

    Other uses of save

       autosar.arch.Model/save
       COM.com/save
       COM/save
       controllib.widget.internal.cstprefs.ToolboxPreferences/save
       DataRecorder/save
       icomm/save
       imaq/save
       instrument/save
       matlab.diagram.ClassViewer/save
       rmidata/save
       sim3d.Actor/save
       Simulink.Bus/save
       Simulink.CodeImporter/save
       Simulink.interface.dictionary.Migrator/save
       Simulink.interface.Dictionary/save
       Simulink.ModelWorkspace/save
       Simulink.sdi/save
       slcoverage.Filter/save
       slreq.LinkSet/save
       slreq.ReqSet/save
       systemcomposer.allocation.AllocationSet/save
       systemcomposer.analysis.ArchitectureInstance/save
       systemcomposer.arch.Model/save
       systemcomposer.profile.Profile/save
       vrworld/save

[Merve ozdas]

thank you, for example if I have a csv file with EEG signals,can I save this like

eeg=csvread("eeg.csv");
save('eeg_file.mat','eeg')% this 'eeg' is from variable that I defined. 

    

Can it be like that?

[Walter Roberson]

@Merve ozdas

Sure, that should work.

Generally speaking, modern style would be to use readmatrix() or readtable() to read csv files, depending on whether the data is expected to be all numeric or not.

csvread() is a wrapper around dlmread() which in turn is a wrapper around fopen() / textscan() / fclose() . And those approaches are still valid -- but the newer approaches are more flexibile. For example the newer functions can be passed a url, and the newer functions are able to handle missing entries, or handle unexpected text in numeric fields.

[Merve ozdas]

okay thank you Walter :)

Answer 2

[KSSV]

A = rand(10) ;
str = 'The above is matrix' ;
save test.mat ; % save A, str into mat file 
load test.mat ; % load the mat file 

Answer 3

[Jan]

In Matlab this is easy:

data = magic(4);  % Arbitrary test data
save('file.mat', 'data')

Answer 4

[Image Analyst]

For example you want to make a mat file called 'answers.mat' containing variables var1 and var2:

save('answers.mat', 'var1', 'var2');