setvartype
Set variable data types
Description
Examples
Set Data Types for Multiple Variables
Use detectImportOptions
to create import options, set multiple variable data types, and then read the data using readtable
.
Create an options object.
opts = detectImportOptions('patients.xls');
Examine the current (detected) data types of the variables.
disp([opts.VariableNames' opts.VariableTypes'])
{'LastName' } {'char' } {'Gender' } {'char' } {'Age' } {'double' } {'Location' } {'char' } {'Height' } {'double' } {'Weight' } {'double' } {'Smoker' } {'logical'} {'Systolic' } {'double' } {'Diastolic' } {'double' } {'SelfAssessedHealthStatus'} {'char' }
Change the data type of multiple variables depending on your import needs.
opts = setvartype(opts,{'LastName','Gender','Location',... 'Smoker','SelfAssessedHealthStatus'},'string'); opts = setvartype(opts,{'Age','Height','Weight',... 'Systolic','Diastolic'},'single');
Examine the updated data types of the variables.
disp([opts.VariableNames' opts.VariableTypes'])
{'LastName' } {'string'} {'Gender' } {'string'} {'Age' } {'single'} {'Location' } {'string'} {'Height' } {'single'} {'Weight' } {'single'} {'Smoker' } {'string'} {'Systolic' } {'single'} {'Diastolic' } {'single'} {'SelfAssessedHealthStatus'} {'string'}
Import the variables with their updated types using readtable
.
T = readtable('patients.xls',opts);
Input Arguments
opts
— File import options
SpreadsheetImportOptions
| DelimitedTextImportOptions
| FixedWidthImportOptions
File import options, specified as a SpreadsheetImportOptions
, DelimitedTextImportOptions
,
or a FixedWidthImportOptions
object created by
the detectImportOptions
function.
The opts
object contains properties that control
the data import process, such as variable properties, data location
properties, replacement rules, and others.
selection
— Selected variables
character vector | string scalar | cell array of character vector | string array | array of indices | logical array
Selected variables, specified as a character vector, string scalar, cell array of character vectors, string array, array of numeric indices, or a logical array.
Variable names (or indices) must be a subset of the names contained in the
VariableNames
property of the opts
object.
Example: 'Height'
Example: {'Height','LastName'}
Example: [5 9]
Data Types: char
| string
| cell
| uint64
| logical
type
— Variable data type
character vector | string scalar | cell array of character vectors | string array
Variable data type, specified as a character vector, string scalar, cell
array of character vectors, or string array containing valid data type
names. The type
argument designates the data types to use
when importing the variable. Import the variables using one of the data
types listed here.
Data | MATLAB® Data Type |
---|---|
Text |
|
Numeric |
Undefined
floating-point numbers
The same conversion process applies
to all the integer data types:
|
Logical |
|
Date and time |
|
Duration |
|
Categorical |
|
Example: opts = setvartype(opts,'Height','double')
changes the data type of the variable Height
to
double
.
Example: opts =
setvartype(opts,{'Weight','LastName'},{'single','string'})
changes the data type of the variable Weight
to
single
and variable LastName
to
string
.
Data Types: char
| string
| cell
Version History
Introduced in R2016b
See Also
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