addvars - Add variables to table or timetable - MATLAB (original) (raw)

Add variables to table or timetable

Syntax

Description

T2 = addvars([T1](#d126e19291),[var1,...,varN](#d126e19310)) adds the arrays specified by var1,…,varN as new variables to the right of the last variable in T1. The input arraysvar1,…,varN can be arrays having any data type, tables, and timetables. All input arguments must have the same number of rows asT1.

For example, to add a column vector named A after the last variable in T1, use T2 = addvars(T1,A).

example

T2 = addvars([T1](#d126e19291),[var1,...,varN](#d126e19310),'After',[location](#d126e19348)) inserts the variables to the right of the table variable indicated bylocation. You can specify location as a variable name, or a numeric or logical index.

For example, to insert a column vector named A after table variable var2, use T2 = addvars(T1,A,'After','var2').

example

T2 = addvars([T1](#d126e19291),[var1,...,varN](#d126e19310),'Before',[location](#d126e19348)) inserts the variables to the left of the table variable indicated bylocation.

For example, to insert a column vector named A before table variable var3, use T2 = addvars(T1,A,'Before','var3').

example

T2 = addvars(___,'NewVariableNames',[newNames](#d126e19431)) renames the added variables in T2 using the names specified bynewNames. The number of names in newNames must be the same as the number of added variables. You can use this syntax with any of the input arguments of the previous syntaxes.

example

Examples

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Create a table. Then add variables from the workspace to the table.

Load arrays from the patients.mat file. Create a table that contains the names, ages, heights, and weights of patients. Then display the first three rows.

load patients T1 = table(LastName,Age,Height,Weight); head(T1,3)

  LastName      Age    Height    Weight
____________    ___    ______    ______

{'Smith'   }    38       71       176  
{'Johnson' }    43       69       163  
{'Williams'}    38       64       131

Add the workspace variables, Gender and Smoker, to the table.

T2 = addvars(T1,Gender,Smoker); head(T2,3)

  LastName      Age    Height    Weight      Gender      Smoker
____________    ___    ______    ______    __________    ______

{'Smith'   }    38       71       176      {'Male'  }    true  
{'Johnson' }    43       69       163      {'Male'  }    false 
{'Williams'}    38       64       131      {'Female'}    false

Create a table. Then insert variables before and after specified locations in the table.

Load arrays from the patients.mat file. Create a table that contains the names and genders of patients. Then display the first three rows.

load patients T1 = table(LastName,Gender); head(T1,3)

  LastName        Gender  
____________    __________

{'Smith'   }    {'Male'  }
{'Johnson' }    {'Male'  }
{'Williams'}    {'Female'}

Insert the workspace variable, Age, before the table variable, Gender. To refer to a table variable by name, specify its name as a character vector.

T2 = addvars(T1,Age,'Before','Gender'); head(T2,3)

  LastName      Age      Gender  
____________    ___    __________

{'Smith'   }    38     {'Male'  }
{'Johnson' }    43     {'Male'  }
{'Williams'}    38     {'Female'}

Insert more variables after Age. Since Age is a table variable in T2, specify its name as a character vector.

T3 = addvars(T2,Height,Weight,'After','Age'); head(T3,3)

  LastName      Age    Height    Weight      Gender  
____________    ___    ______    ______    __________

{'Smith'   }    38       71       176      {'Male'  }
{'Johnson' }    43       69       163      {'Male'  }
{'Williams'}    38       64       131      {'Female'}

Insert Smoker after the first table variable. You can specify variables by position in the table instead of by name.

T4 = addvars(T3,Smoker,'After',1); head(T4,3)

  LastName      Smoker    Age    Height    Weight      Gender  
____________    ______    ___    ______    ______    __________

{'Smith'   }    true      38       71       176      {'Male'  }
{'Johnson' }    false     43       69       163      {'Male'  }
{'Williams'}    false     38       64       131      {'Female'}

Create a table. Add variables and give them new names in the table.

First, create a table from workspace variables.

load patients T1 = table(LastName,Age,Gender,Smoker); head(T1,3)

  LastName      Age      Gender      Smoker
____________    ___    __________    ______

{'Smith'   }    38     {'Male'  }    true  
{'Johnson' }    43     {'Male'  }    false 
{'Williams'}    38     {'Female'}    false

Combine Diastolic and Systolic into one matrix with two columns. Name the new table variable BloodPressure.

T2 = addvars(T1,[Diastolic Systolic],'NewVariableNames','BloodPressure'); head(T2,3)

  LastName      Age      Gender      Smoker    BloodPressure
____________    ___    __________    ______    _____________

{'Smith'   }    38     {'Male'  }    true        93    124  
{'Johnson' }    43     {'Male'  }    false       77    109  
{'Williams'}    38     {'Female'}    false       83    125

Add Height and Weight as new table variables. Rename them Inches and Pounds.

T3 = addvars(T2,Height,Weight,'Before','Smoker','NewVariableNames',{'Inches','Pounds'}); head(T3,3)

  LastName      Age      Gender      Inches    Pounds    Smoker    BloodPressure
____________    ___    __________    ______    ______    ______    _____________

{'Smith'   }    38     {'Male'  }      71       176      true        93    124  
{'Johnson' }    43     {'Male'  }      69       163      false       77    109  
{'Williams'}    38     {'Female'}      64       131      false       83    125

Input Arguments

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Input table, specified as a table or timetable.

Variables to add to the output table, specified as arrays, tables, and timetables. The variables specified by var1,...,varN all must have the same number of rows as the input tableT1.

Example: T2 = addvars(T1,A) inserts the workspace variables A to the right of the last table variable.

Example: T2 = addvars(T1,X,Y,Z) inserts the workspace variables X, Y, andZ.

Location to insert added variables, specified as a character vector, string scalar, integer, or logical array.

If location is a character vector or string scalar, then it is the name of a variable in the input tableT1.
If location is the integern, then it specifies the nth variable in T1.
If location is a logical array, whosenth element is 1 (true), then it specifies thenth variable in T1. All other elements of location must be0 (false).

Example: T2 = addvars(T1,Latitude,'Before','Longitude') insert the workspace variable Latitude to the left of the table variable named Longitude.

Example: T2 = addvars(T1,Y,Z,'After','X') inserts the workspace variables Y and Z to the right of the table variable named X.

Names of the added variables, specified as a character vector, cell array of character vectors, or string array.

Example: T2 = addvars(T1,lat,lon,'NewVariableNames',{'Latitude','Longitude'}) inserts the workspace variables lat andlon and names the corresponding table variables'Latitude' and'Longitude'.

Limitations

Use single quotes for the input names 'Before','After', and 'NewVariableNames'. To avoid confusion with variable inputs, do not use double-quoted string scalars (such as "Before") for these names.

Extended Capabilities

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

Version History

Introduced in R2018a