Modify Units, Descriptions, and Table Variable Names

This example shows how to access and modify table properties for variable units, descriptions and names. You also can edit these property values using the Variables Editor.

Load Sample Data

Load the sample patients data and create a table.

load patients
BloodPressure = [Systolic Diastolic];

T = table(Gender,Age,Height,Weight,Smoker,BloodPressure);

Display the first five rows of the table, T.

T(1:5,:)

ans=5×6 table
      Gender      Age    Height    Weight    Smoker    BloodPressure
    __________    ___    ______    ______    ______    _____________

    {'Male'  }    38       71       176      true       124     93  
    {'Male'  }    43       69       163      false      109     77  
    {'Female'}    38       64       131      false      125     83  
    {'Female'}    40       67       133      false      117     75  
    {'Female'}    49       64       119      false      122     80  

T has 100 rows and 6 variables.

Add Variable Units

Specify units for each variable in the table by modifying the table property, VariableUnits. Specify the variable units as a cell array of character vectors.

T.Properties.VariableUnits = {'' 'Yrs' 'In' 'Lbs' '' ''};

An individual empty character vector within the cell array indicates that the corresponding variable does not have units.

Add a Variable Description for a Single Variable

Add a variable description for the variable, BloodPressure. Assign a single character vector to the element of the cell array containing the description for BloodPressure.

T.Properties.VariableDescriptions{'BloodPressure'} = 'Systolic/Diastolic';

You can use the variable name, 'BloodPressure', or the numeric index of the variable, 6, to index into the cell array of character vectors containing the variable descriptions.

Summarize the Table

View the data type, description, units, and other descriptive statistics for each variable by using summary to summarize the table.

summary(T)

Variables:

    Gender: 100x1 cell array of character vectors

    Age: 100x1 double

        Properties:
            Units:  Yrs
        Values:

            Min        25  
            Median     39  
            Max        50  

    Height: 100x1 double

        Properties:
            Units:  In
        Values:

            Min          60   
            Median       67   
            Max          72   

    Weight: 100x1 double

        Properties:
            Units:  Lbs
        Values:

            Min          111  
            Median     142.5  
            Max          202  

    Smoker: 100x1 logical

        Values:

            True        34   
            False       66   

    BloodPressure: 100x2 double

        Properties:
            Description:  Systolic/Diastolic
        Values:
                      BloodPressure_1    BloodPressure_2
                      _______________    _______________

            Min             109                 68      
            Median          122               81.5      
            Max             138                 99      

The BloodPressure variable has a description and the Age, Height, Weight, and BloodPressure variables have units.

Change a Variable Name

Change the variable name for the first variable from Gender to Sex.

T.Properties.VariableNames{'Gender'} = 'Sex';

Display the first five rows of the table, T.

T(1:5,:)

ans=5×6 table
       Sex        Age    Height    Weight    Smoker    BloodPressure
    __________    ___    ______    ______    ______    _____________

    {'Male'  }    38       71       176      true       124     93  
    {'Male'  }    43       69       163      false      109     77  
    {'Female'}    38       64       131      false      125     83  
    {'Female'}    40       67       133      false      117     75  
    {'Female'}    49       64       119      false      122     80  

In addition to properties for variable units, descriptions and names, there are table properties for row and dimension names, a table description, and user data.