renamecats

Rename categories in categorical array

Syntax

B = renamecats(A,newnames)

B = renamecats(A,oldnames,newnames)

Description

B = renamecats(A,newnames) renames all the categories in the categorical array, A. Elements of B use the new category names.

B = renamecats(A,oldnames,newnames) renames only the categories specified by oldnames.

Examples

Rename All Categories

Create a categorical array containing states from New England.

A = categorical({'MA';'ME';'CT';'VT';'ME';'NH';'VT';'MA';'NH';'CT';'RI'})

A = 11x1 categorical
     MA 
     ME 
     CT 
     VT 
     ME 
     NH 
     VT 
     MA 
     NH 
     CT 
     RI 

A is an 11-by-1 categorical array.

Display the categories of A.

categories(A)

ans = 6x1 cell
    {'CT'}
    {'MA'}
    {'ME'}
    {'NH'}
    {'RI'}
    {'VT'}

A has six categories.

Rename the categories to use the full state name instead of the abbreviation.

B = renamecats(A,{'Connecticut','Massachusetts',...
    'Maine','New Hampshire','Rhode Island' 'Vermont'})

B = 11x1 categorical
     Massachusetts 
     Maine 
     Connecticut 
     Vermont 
     Maine 
     New Hampshire 
     Vermont 
     Massachusetts 
     New Hampshire 
     Connecticut 
     Rhode Island 

Elements of B use the new category names.

Display the categories of B.

categories(B)

ans = 6x1 cell
    {'Connecticut'  }
    {'Massachusetts'}
    {'Maine'        }
    {'New Hampshire'}
    {'Rhode Island' }
    {'Vermont'      }

Rename One Category

Create a categorical array containing colors.

A = categorical({'red' 'blue'; 'purple' 'white'; 'green' 'red'})

A = 3x2 categorical
     red         blue  
     purple      white 
     green       red   

A is a 3-by-2 categorical array.

Display the categories of A.

categories(A)

ans = 5x1 cell
    {'blue'  }
    {'green' }
    {'purple'}
    {'red'   }
    {'white' }

A has five categories that are listed in alphabetical order.

Change the category name from purple to violet.

B = renamecats(A,'purple','violet')

B = 3x2 categorical
     red         blue  
     violet      white 
     green       red   

The element B(2,1) is violet instead of purple.

Display the categories of B.

categories(B)

ans = 5x1 cell
    {'blue'  }
    {'green' }
    {'violet'}
    {'red'   }
    {'white' }

violet replaces purple and the categories are no longer in alphabetical order. Note that the category has not changed its position.

Input Arguments

A — Categorical array

vector | matrix | multidimensional array

Categorical array, specified as a vector, matrix, or multidimensional array.

newnames — New category names for B

character vector | cell array of character vectors | string array

New category names for B, specified as a character vector, a cell array of character vectors, or a string array. The new category names must be unique, and must not duplicate any existing names.

oldnames — Old category names from A

character vector | cell array of character vectors | string array

Old category names from A, specified as a character vector, a cell array of character vectors, or a string array.

Tips

• Renaming categories does not change their position in categories(B). Use reordercats to change the category ordering. For example, you can use B = reordercats(B,sort(categories(B))) to put the categories in alphabetical order.

Extended Capabilities

Tall Arrays

Calculate with arrays that have more rows than fit in memory.

This function fully supports tall arrays. For more information, see Tall Arrays.

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

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.

Distributed Arrays

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

This function fully supports distributed arrays. For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).

Version History

Introduced in R2013b