csvwrite

(Not recommended) Write comma-separated value file

csvwrite is not recommended. Use writematrix instead. For more information, see Compatibility Considerations.

Syntax

csvwrite(filename,M)

csvwrite(filename,M,row,col)

Description

csvwrite(filename,M) writes matrix M to file filename as comma-separated values.

csvwrite(filename,M,row,col) writes matrix M to file filename starting at the specified row and column offset. The row and column arguments are zero based, so that row=0 and col=0 specify the first value in the file.

Examples

Write Matrix to Comma-Separated Value File

Create an array of sample data M.

M = magic(3)

M = 3×3

     8     1     6
     3     5     7
     4     9     2

Write matrix M to the file 'myFile.txt'.

csvwrite('myFile.txt',M)

View the data in the file.

type('myFile.txt')

8,1,6
3,5,7
4,9,2

Write Matrix Starting at Offset

Write a matrix to a file starting at a defined offset position.

Create an array of sample data M.

M = magic(3)

M = 3×3

     8     1     6
     3     5     7
     4     9     2

Define the starting offsets to skip one row and two columns.

row = 1 ;
col = 2 ;

Write matrix M to the file 'myFile.txt', starting at the offset position.

csvwrite('myFile.txt',M,row,col)

View the data in the file.

type('myFile.txt')

,,,,
,,8,1,6
,,3,5,7
,,4,9,2

Input Arguments

filename — File name

character vector | string

File name, specified as a character vector or string.

Example: 'myFile.dat'

Data Types: char | string

M — Numeric data to write

matrix

Numeric data to write, specified as a matrix of numeric values.

Example: [1,2,3;4,5,6]

Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical
Complex Number Support: Yes

row — Row offset

0 (default) | scalar

Row offset, specified as a scalar. The row offset indicates the number of rows to skip before writing the numeric data. row is zero-based, so that row = 0 instructs MATLAB^® to begin writing in the first row of the destination file. Skipped rows are populated with commas.

col — Column offset

0 (default) | scalar

Column offset, specified as a scalar. The column offset indicates the number of columns to skip before writing the numeric data. col is zero-based, so that col = 0 instructs MATLAB to begin writing in the first column of the destination file. Skipped columns are separated by commas.

Limitations

• csvwrite writes a maximum of five significant digits. If you need greater precision, use dlmwrite with a precision argument.

• csvwrite does not accept cell arrays for the input matrix M. To export a cell array that contains only numeric data, use cell2mat to convert the cell array to a numeric matrix before calling csvwrite.

Algorithms

• csvwrite terminates each line with a line feed character ('\n' or char(10)) and no carriage return.

Version History

Introduced before R2006a

R2019a: csvwrite is not recommended

csvwrite is not recommended. Use writematrix instead. There are no plans to remove csvwrite.

Starting in R2019a, use the writematrix function to write a matrix to a comma separated text file. The writematrix function has better cross-platform support and performance over the csvwrite function.

This table shows typical usages of csvwrite and how to update your code to use writematrix instead.

Not Recommended	Recommended
csvwrite('mydata.txt',M)	writematrix(M,'mydata.txt')