splitvars

Split multicolumn variables in table or timetable

Syntax

T2 = splitvars(T1)

T2 = splitvars(T1,vars)

T2 = splitvars(T1,vars,NewVariableNames=newNames)

Description

T2 = splitvars(T1) splits all multicolumn variables in T1 so that they are single-column variables in T2. All single-column variables from T1 are unaltered.

If a variable in T1 has multiple columns, then splitvars makes unique names for the new variables in T2 from the name of the original variable in T1.
If a variable in T1 is a table itself, then splitvars uses the names of its variables (and, if necessary, the name of that table) to make unique names for the new variables in T2.

For example, if T1 has a variable named var4, and var4 has two columns, then splitvars(T1) splits var4 into two variables named var4_1 and var4_2 in the output table.

To merge variables into one multicolumn variable, use the mergevars function.

example

T2 = splitvars(T1,vars) splits only the table variables specified by vars. You can specify variables by name, by position, or using logical indices.

example

T2 = splitvars(T1,vars,NewVariableNames=newNames) assigns new names to the designated variables that are split out of T1 and copied to T2.

example

Examples

collapse all

Split Variables

Open Live Script

Create a table from workspace variables. Some of the variables are matrices with multiple columns.

A = (1:3)';
B = [5 11 12; 20 30 50; 0.1 3.4 5.9]';
C = ["a" "XX";"b" "YY";"c" "ZZ"];
D = [128 256 512]';
T1 = table(A,B,C,D)

T1=3×4 table
    A           B                 C          D 
    _    ________________    ___________    ___

    1     5     20    0.1    "a"    "XX"    128
    2    11     30    3.4    "b"    "YY"    256
    3    12     50    5.9    "c"    "ZZ"    512

Split the variables B and C. All variables in the output table have one column.

T2 = splitvars(T1)

T2=3×7 table
    A    B_1    B_2    B_3    C_1    C_2      D 
    _    ___    ___    ___    ___    ____    ___

    1     5     20     0.1    "a"    "XX"    128
    2    11     30     3.4    "b"    "YY"    256
    3    12     50     5.9    "c"    "ZZ"    512

Specify Variable

Open Live Script

Create a table that contains tables, using arrays of data from the patients.mat file.

load patients
Personal_Data = table(Age,Smoker);
BMI_Data = table(Height,Weight);
BloodPressure = table(Systolic,Diastolic);
LastName = string(LastName);
T1 = table(LastName,Personal_Data,BMI_Data,BloodPressure)

T1=100×4 table
     LastName     Personal_Data        BMI_Data            BloodPressure    
    __________    _____________    ________________    _____________________

                  Age    Smoker    Height    Weight    Systolic    Diastolic
                  ___    ______    ______    ______    ________    _________
                                                                            
    "Smith"       38     true        71       176        124          93    
    "Johnson"     43     false       69       163        109          77    
    "Williams"    38     false       64       131        125          83    
    "Jones"       40     false       67       133        117          75    
    "Brown"       49     false       64       119        122          80    
    "Davis"       46     false       68       142        121          70    
    "Miller"      33     true        64       142        130          88    
    "Wilson"      40     false       68       180        115          82    
    "Moore"       28     false       68       183        115          78    
    "Taylor"      31     false       66       132        118          86    
    "Anderson"    45     false       68       128        114          77    
    "Thomas"      42     false       66       137        115          68    
    "Jackson"     25     false       71       174        127          74    
    "White"       39     true        72       202        130          95    
    "Harris"      36     false       65       129        114          79    
    "Martin"      48     true        71       181        130          92    
      ⋮

Specify BloodPressure as the variable to split.

T2 = splitvars(T1,"BloodPressure")

T2=100×5 table
     LastName     Personal_Data        BMI_Data        Systolic    Diastolic
    __________    _____________    ________________    ________    _________

                  Age    Smoker    Height    Weight                         
                  ___    ______    ______    ______                         
                                                                            
    "Smith"       38     true        71       176        124          93    
    "Johnson"     43     false       69       163        109          77    
    "Williams"    38     false       64       131        125          83    
    "Jones"       40     false       67       133        117          75    
    "Brown"       49     false       64       119        122          80    
    "Davis"       46     false       68       142        121          70    
    "Miller"      33     true        64       142        130          88    
    "Wilson"      40     false       68       180        115          82    
    "Moore"       28     false       68       183        115          78    
    "Taylor"      31     false       66       132        118          86    
    "Anderson"    45     false       68       128        114          77    
    "Thomas"      42     false       66       137        115          68    
    "Jackson"     25     false       71       174        127          74    
    "White"       39     true        72       202        130          95    
    "Harris"      36     false       65       129        114          79    
    "Martin"      48     true        71       181        130          92    
      ⋮

To specify multiple variables by name, use a string array.

T3 = splitvars(T1,["BMI_Data" "BloodPressure"])

T3=100×6 table
     LastName     Personal_Data    Height    Weight    Systolic    Diastolic
    __________    _____________    ______    ______    ________    _________

                  Age    Smoker                                             
                  ___    ______                                             
                                                                            
    "Smith"       38     true        71       176        124          93    
    "Johnson"     43     false       69       163        109          77    
    "Williams"    38     false       64       131        125          83    
    "Jones"       40     false       67       133        117          75    
    "Brown"       49     false       64       119        122          80    
    "Davis"       46     false       68       142        121          70    
    "Miller"      33     true        64       142        130          88    
    "Wilson"      40     false       68       180        115          82    
    "Moore"       28     false       68       183        115          78    
    "Taylor"      31     false       66       132        118          86    
    "Anderson"    45     false       68       128        114          77    
    "Thomas"      42     false       66       137        115          68    
    "Jackson"     25     false       71       174        127          74    
    "White"       39     true        72       202        130          95    
    "Harris"      36     false       65       129        114          79    
    "Martin"      48     true        71       181        130          92    
      ⋮

To specify variables by position, use a numeric array.

T4 = splitvars(T1,[2 4])

T4=100×6 table
     LastName     Age    Smoker        BMI_Data        Systolic    Diastolic
    __________    ___    ______    ________________    ________    _________

                                   Height    Weight                         
                                   ______    ______                         
                                                                            
    "Smith"       38     true        71       176        124          93    
    "Johnson"     43     false       69       163        109          77    
    "Williams"    38     false       64       131        125          83    
    "Jones"       40     false       67       133        117          75    
    "Brown"       49     false       64       119        122          80    
    "Davis"       46     false       68       142        121          70    
    "Miller"      33     true        64       142        130          88    
    "Wilson"      40     false       68       180        115          82    
    "Moore"       28     false       68       183        115          78    
    "Taylor"      31     false       66       132        118          86    
    "Anderson"    45     false       68       128        114          77    
    "Thomas"      42     false       66       137        115          68    
    "Jackson"     25     false       71       174        127          74    
    "White"       39     true        72       202        130          95    
    "Harris"      36     false       65       129        114          79    
    "Martin"      48     true        71       181        130          92    
      ⋮

New Names for Split Variables

Open Live Script

Create a table that contains multi-column variables, using data from the patients.mat file.

load patients
Personal_Data = [Age,Height,Weight];
BloodPressure = [Systolic,Diastolic];
T1 = table(LastName,Smoker,Personal_Data,BloodPressure)

T1=100×4 table
      LastName      Smoker     Personal_Data      BloodPressure
    ____________    ______    ________________    _____________

    {'Smith'   }    true      38     71    176     124     93  
    {'Johnson' }    false     43     69    163     109     77  
    {'Williams'}    false     38     64    131     125     83  
    {'Jones'   }    false     40     67    133     117     75  
    {'Brown'   }    false     49     64    119     122     80  
    {'Davis'   }    false     46     68    142     121     70  
    {'Miller'  }    true      33     64    142     130     88  
    {'Wilson'  }    false     40     68    180     115     82  
    {'Moore'   }    false     28     68    183     115     78  
    {'Taylor'  }    false     31     66    132     118     86  
    {'Anderson'}    false     45     68    128     114     77  
    {'Thomas'  }    false     42     66    137     115     68  
    {'Jackson' }    false     25     71    174     127     74  
    {'White'   }    true      39     72    202     130     95  
    {'Harris'  }    false     36     65    129     114     79  
    {'Martin'  }    true      48     71    181     130     92  
      ⋮

Split BloodPressure and specify new names for the new variables in the output table.

T2 = splitvars(T1,"BloodPressure",NewVariableNames=["Systolic" "Diastolic"])

T2=100×5 table
      LastName      Smoker     Personal_Data      Systolic    Diastolic
    ____________    ______    ________________    ________    _________

    {'Smith'   }    true      38     71    176      124          93    
    {'Johnson' }    false     43     69    163      109          77    
    {'Williams'}    false     38     64    131      125          83    
    {'Jones'   }    false     40     67    133      117          75    
    {'Brown'   }    false     49     64    119      122          80    
    {'Davis'   }    false     46     68    142      121          70    
    {'Miller'  }    true      33     64    142      130          88    
    {'Wilson'  }    false     40     68    180      115          82    
    {'Moore'   }    false     28     68    183      115          78    
    {'Taylor'  }    false     31     66    132      118          86    
    {'Anderson'}    false     45     68    128      114          77    
    {'Thomas'  }    false     42     66    137      115          68    
    {'Jackson' }    false     25     71    174      127          74    
    {'White'   }    true      39     72    202      130          95    
    {'Harris'  }    false     36     65    129      114          79    
    {'Martin'  }    true      48     71    181      130          92    
      ⋮

Split both BMI_Data and BloodPressure. For each variable being split, you must provide a cell array with the correct number of new names.

T3 = splitvars(T1,["Personal_Data" "BloodPressure"], ...
     NewVariableNames={["Age" "Height" "Weight"] ["Systolic" "Diastolic"]})

T3=100×7 table
      LastName      Smoker    Age    Height    Weight    Systolic    Diastolic
    ____________    ______    ___    ______    ______    ________    _________

    {'Smith'   }    true      38       71       176        124          93    
    {'Johnson' }    false     43       69       163        109          77    
    {'Williams'}    false     38       64       131        125          83    
    {'Jones'   }    false     40       67       133        117          75    
    {'Brown'   }    false     49       64       119        122          80    
    {'Davis'   }    false     46       68       142        121          70    
    {'Miller'  }    true      33       64       142        130          88    
    {'Wilson'  }    false     40       68       180        115          82    
    {'Moore'   }    false     28       68       183        115          78    
    {'Taylor'  }    false     31       66       132        118          86    
    {'Anderson'}    false     45       68       128        114          77    
    {'Thomas'  }    false     42       66       137        115          68    
    {'Jackson' }    false     25       71       174        127          74    
    {'White'   }    true      39       72       202        130          95    
    {'Harris'  }    false     36       65       129        114          79    
    {'Martin'  }    true      48       71       181        130          92    
      ⋮

Input Arguments

collapse all

`T1` — Input table
table | timetable

Input table, specified as a table or timetable.

`vars` — Variables in input table
string array | character vector | cell array of character vectors | `pattern` scalar | numeric array | logical array

Variables in the input table, specified as a string array, character vector, cell array of character vectors, pattern scalar, numeric array, or logical array.

`newNames` — Names of split variables
string array | cell array of character vectors

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

Output Arguments

collapse all

`T2` — Output table with split variables
table | timetable

Output table with split variables, returned as a table or timetable.

Extended Capabilities

expand all

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

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

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

Usage notes and limitations:

The vars input argument does not support pattern expressions.
The value of the NewVariableNames name-value argument must be constant.
The variables that are split cannot have a variable number of columns.

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 splitvars function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.

Version History

Introduced in R2018a

splitvars

Syntax

Description

Examples

Split Variables

Specify Variable

New Names for Split Variables

Input Arguments

`T1` — Input table
table | timetable

`vars` — Variables in input table
string array | character vector | cell array of character vectors | `pattern` scalar | numeric array | logical array

`newNames` — Names of split variables
string array | cell array of character vectors

Output Arguments

`T2` — Output table with split variables
table | timetable

Extended Capabilities

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

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

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

Thread-Based Environment
Run code in the background using MATLAB® `backgroundPool` or accelerate code with Parallel Computing Toolbox™ `ThreadPool`.

Version History

See Also

Topics

splitvars

Syntax

Description

Examples

Split Variables

Specify Variable

New Names for Split Variables

Input Arguments

T1 — Input table table | timetable

vars — Variables in input table string array | character vector | cell array of character vectors | pattern scalar | numeric array | logical array

newNames — Names of split variables string array | cell array of character vectors

Output Arguments

T2 — Output table with split variables table | timetable

Extended Capabilities

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

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

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

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

Version History

See Also

Topics

`T1` — Input table
table | timetable

`vars` — Variables in input table
string array | character vector | cell array of character vectors | `pattern` scalar | numeric array | logical array

`newNames` — Names of split variables
string array | cell array of character vectors

`T2` — Output table with split variables
table | timetable

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

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

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

Thread-Based Environment
Run code in the background using MATLAB® `backgroundPool` or accelerate code with Parallel Computing Toolbox™ `ThreadPool`.