mat2dataset

(Not Recommended) Convert matrix to dataset array

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The dataset data type is not recommended. To work with heterogeneous data, use the MATLAB® table data type instead. See MATLAB table documentation for more information.

Syntax

ds = mat2dataset(X)
ds = mat2dataset(X,Name,Value)

Description

ds = mat2dataset(X) converts a matrix to a dataset array.

example

ds = mat2dataset(X,Name,Value) performs the conversion using additional options specified by one or more Name,Value pair arguments.

example

Examples

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Open Live Script

Convert a matrix to a dataset array using the default options.

Load sample data. 

load('fisheriris')
X = meas;
size(X)
ans = 1×2

   150     4

Convert the matrix to a dataset array. 

ds = mat2dataset(X);
size(ds)
ans = 1×2

   150     4


ds(1:5,:)
ans = 
    X1     X2     X3     X4 
    5.1    3.5    1.4    0.2
    4.9      3    1.4    0.2
    4.7    3.2    1.3    0.2
    4.6    3.1    1.5    0.2
      5    3.6    1.4    0.2

When you do not specify variable names, mat2dataset uses the matrix name and column numbers to create default variable names.

Open Live Script

Load sample data. 

load('fisheriris')
X = meas;
size(X)
ans = 1×2

   150     4

Convert the matrix to a dataset array, providing a variable name for each of the four column of X. 

ds = mat2dataset(X,'VarNames',{'SLength',...
'SWidth','PLength','PWidth'});
size(ds)
ans = 1×2

   150     4


ds(1:5,:)
ans = 
    SLength    SWidth    PLength    PWidth
    5.1        3.5       1.4        0.2   
    4.9          3       1.4        0.2   
    4.7        3.2       1.3        0.2   
    4.6        3.1       1.5        0.2   
      5        3.6       1.4        0.2
Open Live Script

Convert a matrix to a dataset array containing multicolumn variables.

Load sample data. 

load('fisheriris')
X = meas;
size(X)
ans = 1×2

   150     4

Convert the matrix to a dataset array, combining the sepal measurements (the first two columns) into one variable named SepalMeas, and the petal measurements (third and fourth columns) into one variable names PetalMeas. 

ds = mat2dataset(X,'NumCols',[2,2],...
'VarNames',{'SepalMeas','PetalMeas'});
ds(1:5,:)
ans = 
    SepalMeas          PetalMeas      
    5.1         3.5    1.4         0.2
    4.9           3    1.4         0.2
    4.7         3.2    1.3         0.2
    4.6         3.1    1.5         0.2
      5         3.6    1.4         0.2

The output dataset array has 150 observations and 2 variables. 

size(ds)
ans = 1×2

   150     2

Input Arguments

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Input matrix to convert to a dataset array, specified as an M-by-N numeric matrix. Each column of X becomes a variable in the output M-by-N dataset array.

Data Types: single | double

Name-Value Arguments

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Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: 'NumCols',[1,1,2,1] specifies that the 3rd and 4th columns of the input matrix should be combined into a single variable.

Variable names for the output dataset array, specified as the comma-separated pair consisting of 'VarNames' and a string array or cell array of character vectors. You must provide a variable name for each variable in ds. The names must be valid MATLAB identifiers, and must be unique.

Example: 'VarNames',{'myVar1','myVar2','myVar3'}

Observation names for the output dataset array, specified as the comma-separated pair consisting of 'ObsNames' and a string array or cell array of character vectors. The names do not need to be valid MATLAB identifiers, but they must be unique.

Number of columns for each variable in ds, specified as the comma-separated pair consisting of 'NumCols' and a vector of nonnegative integers. When the number of columns for a variable is greater than one, mat2dataset combines multiple columns in X into a single variable in ds. The vector you assign to NumCols must sum to size(X,2).

For example, to convert a matrix with eight columns into a dataset array with five variables, specify a vector with five elements that sum to eight, such as 'NumCols',[1,1,3,1,2].

Output Arguments

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Output dataset array, returned by default with a variable for each column of X, and an observation for each row of X. If you specify NumCols, then the number of variables in ds is equal to the length of the specified vector of column numbers.

Version History

Introduced in R2012b

See Also

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