Write Data to Text Files

Export tabular data contained in tables, cell arrays, or numeric arrays from the MATLAB^® workspace to text files.

Export Table to Text File

You can export tabular data from MATLAB® workspace into a text file using the writetable function. Create a sample table, write the table to text file, and then write the table to text file with additional options.

Create a sample table, T, containing the variables Pitch, Shape, Price and Stock.

Pitch = [0.7;0.8;1;1.25;1.5];
Shape = {'Pan';'Round';'Button';'Pan';'Round'};
Price = [10.0;13.59;10.50;12.00;16.69];
Stock = [376;502;465;1091;562];
T = table(Pitch,Shape,Price,Stock)

T=5×4 table
    Pitch      Shape       Price    Stock
    _____    __________    _____    _____

     0.7     {'Pan'   }       10     376 
     0.8     {'Round' }    13.59     502 
       1     {'Button'}     10.5     465 
    1.25     {'Pan'   }       12    1091 
     1.5     {'Round' }    16.69     562 

Export the table, T, to a text file named tabledata.txt. View the contents of the file. By default, writetable writes comma-separated data, includes table variable names as column headings.

writetable(T,'tabledata.txt');
type tabledata.txt

Pitch,Shape,Price,Stock
0.7,Pan,10,376
0.8,Round,13.59,502
1,Button,10.5,465
1.25,Pan,12,1091
1.5,Round,16.69,562

Create a table T2 which includes row names using the RowNames name-value pair argument.

rowNames = {'M4';'M5';'M6';'M8';'M10'};
T2 = table(Pitch,Shape,Price,Stock,'RowNames',rowNames)

T2=5×4 table
           Pitch      Shape       Price    Stock
           _____    __________    _____    _____

    M4      0.7     {'Pan'   }       10     376 
    M5      0.8     {'Round' }    13.59     502 
    M6        1     {'Button'}     10.5     465 
    M8     1.25     {'Pan'   }       12    1091 
    M10     1.5     {'Round' }    16.69     562 

Export T2 to a tab-delimited text file named tabledata2.txt. Use the Delimiter name-value pair argument to specify a tab delimiter, and the WriteRowNames name-value pair argument to include row names. View the contents of the file.

writetable(T2,'tabledata2.txt','Delimiter','\t','WriteRowNames',true);
type tabledata2.txt

Row	Pitch	Shape	Price	Stock
M4	0.7	Pan	10	376
M5	0.8	Round	13.59	502
M6	1	Button	10.5	465
M8	1.25	Pan	12	1091
M10	1.5	Round	16.69	562

Export Cell Array to Text File

You can export a cell array from MATLAB® workspace into a text file in one of these ways:

• Use the writecell function to export the cell array to a text file.

• Use fprintf to export the cell array by specifying the format of the output data.

Create a sample cell array C.

C = {'Atkins',32,77.3,'M';'Cheng',30,99.8,'F';'Lam',31,80.2,'M'}

C = 3×4 cell array
    {'Atkins'}    {[32]}    {[77.3000]}    {'M'}
    {'Cheng' }    {[30]}    {[99.8000]}    {'F'}
    {'Lam'   }    {[31]}    {[80.2000]}    {'M'}

Export the cell array using writecell.

writecell(C,'data.dat')

View the contents of the file.

type data.dat

Atkins,32,77.3,M
Cheng,30,99.8,F
Lam,31,80.2,M

Alternatively, import the cell array using fprintf. Open a file that you can write to named celldata.dat. Define formatSpec using the format specifiers to describe the pattern of the data in the file. Typical format specifiers include '%s' for a character vector, '%d' for an integer, or '%f' for a floating-point number. Separate each format specifier with a space to indicate a space delimiter for the output file. Include a newline character at the end of each row of data ('\n').

fileID = fopen('celldata.dat','w');
formatSpec = '%s %d %2.1f %s\n';

Determine the size of C and export one row of data at a time using the fprintf function. Then close the file. fprintf writes a space-delimited file.

[nrows,ncols] = size(C);
for row = 1:nrows
    fprintf(fileID,formatSpec,C{row,:});
end
fclose(fileID);

View the contents of the file.

type celldata.dat

Atkins 32 77.3 M
Cheng 30 99.8 F
Lam 31 80.2 M

Export Numeric Array to Text File

You can export a numerical array to a text file using writematrix.

Create a numeric array A.

A = magic(5)/10 

Write the numeric array to myData.dat and specify the delimiter to be ';'. Then, view the contents of the file.

writematrix(A,'myData.dat','Delimiter',';')  
type myData.dat

1.7;2.4;0.1;0.8;1.5
2.3;0.5;0.7;1.4;1.6
0.4;0.6;1.3;2;2.2
1;1.2;1.9;2.1;0.3
1.1;1.8;2.5;0.2;0.9