mat2str

Convert matrix to characters

Syntax

chr = mat2str(X)

chr = mat2str(X,n)

chr = mat2str(___,'class')

Description

chr = mat2str(X) converts the numeric or logical matrix X into a character vector that represents the matrix, with up to 15 digits of precision.

You can use chr as input to the eval function. For example, A = eval(chr) reproduces the values from the original matrix to the precision specified in chr.

chr = mat2str(X,n) converts X using n digits of precision.

chr = mat2str(___,'class') includes the name of the class, or data type, of X in chr. You can use this syntax with any of the arguments from the previous syntaxes.

If you use this syntax to produce chr, then A = eval(chr) also reproduces the data type of the original matrix.

Examples

Convert Matrix

Convert a numeric matrix to a character vector.

chr = mat2str([3.85 2.91; 7.74 8.99])

chr = 
'[3.85 2.91;7.74 8.99]'

You can convert chr back to a numeric matrix using the eval function.

A = eval(chr)

A = 2×2

    3.8500    2.9100
    7.7400    8.9900

Specify Precision

Convert a numeric matrix to a character vector, to three digits of precision.

chr = mat2str([3.1416 2.7183],3)

chr = 
'[3.14 2.72]'

Convert Integers

Create an array of integers and convert it to a character vector. By default, the output of mat2str represents an array of doubles. To represent a different numeric type in the output, use the 'class' input argument.

Create a vector of 16-bit unsigned integers.

X = uint16([256 512])

X = 1×2 uint16 row vector

   256   512

Convert X to a character vector, including the data type of X.

chr = mat2str(X,'class')

chr = 
'uint16([256 512])'

Convert chr back to an array of integers. A has the same values and data type as X.

A = eval(chr)

A = 1×2 uint16 row vector

   256   512

Input Arguments

X — Input array

numeric matrix | logical matrix

Input array, specified as a numeric or logical matrix.

n — Digits of precision

positive integer

Digits of precision, specified as a positive integer.

Tips

• mat2str returns character arrays only. Starting in R2016b, you can convert numeric arrays to string arrays using the string function.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• The function mat2str does not support character vectors and string scalars as input arrays.

• Digits of precision must be compile time constant.

• Input array must be numeric matrix or logical matrix.

• Dynamic memory allocation must be enabled for code generation.

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.

GPU Arrays

Accelerate code by running on a graphics processing unit (GPU) using Parallel Computing Toolbox™.

The mat2str function supports GPU array input with these usage notes and limitations:

This function accepts GPU arrays, but does not run on a GPU.

For more information, see Run MATLAB Functions on a GPU (Parallel Computing Toolbox).

Distributed Arrays

Partition large arrays across the combined memory of your cluster using Parallel Computing Toolbox™.

Usage notes and limitations:

This function operates on distributed arrays, but executes in the client MATLAB^®.

For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).

Version History

Introduced before R2006a

R2025a: Code generation support

You can generate C/C++ code for the mat2str function.