width

Number of table variables

Syntax

w = width(T)

Description

w = width(T) returns the number of variables in table T.

width(T) is equivalent to size(T,2).

Examples

Number of Variables in Table

Create a table, T.

LastName = ["Smith";"Chen";"Williams";"Jones";"Lopez"];
Age = [38;43;38;40;49];
Height = [71;69;64;67;64];
Weight = [176;163;131;133;119];
BloodPressure = [124 93; 109 77; 125 83; 117 75; 122 80];

T = table(Age,Height,Weight,BloodPressure,RowNames=LastName)

T=5×4 table
                Age    Height    Weight    BloodPressure
                ___    ______    ______    _____________

    Smith       38       71       176       124     93  
    Chen        43       69       163       109     77  
    Williams    38       64       131       125     83  
    Jones       40       67       133       117     75  
    Lopez       49       64       119       122     80  

Return the number of variables in table T. The variable BloodPressure counts as one variable even though it contains two columns. The set of row names does not count as a variable.

w = width(T)

w = 
4

Input Arguments

T — Input table or array

table | array

Input table or array.

Output Arguments

w — Number of variables

positive integer scalar

Number of variables, returned as a positive integer scalar.

A table variable can be a vector, matrix, or multidimensional array. Even if a table variable is an array with multiple columns, the width function counts it as one table variable.

Extended Capabilities

Tall Arrays

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

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

C/C++ Code Generation

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

This function fully supports code generation. For more information, see Code Generation for Tables (MATLAB Coder).

• Starting in R2021b, the input can be an array, a table, or a timetable. In releases R2019b to R2021a, only tables and timetables are supported.

GPU Code Generation

Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

Refer to the usage notes and limitations in the C/C++ Code Generation section. The same usage notes and limitations apply to GPU code generation.

Thread-Based Environment

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

The width 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 width function fully supports GPU arrays. To run the function on a GPU, specify the input data as a gpuArray (Parallel Computing Toolbox). 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™.

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

Version History

Introduced in R2013b

R2020b: width returns the number of columns of an array

The width function returns the number of variables of a table or timetable, or the number of columns of an input array having any other data type. In previous releases, calling width resulted in an error if the input was not a table or timetable.