Format Tabular Data in Apps - MATLAB & Simulink (original) (raw)

Table arrays are useful for storing tabular data as MATLAB® variables. For example, you can call the readtable function to create a table array from a spreadsheet. You can use aTable UI component to display table array data in apps and to take advantage of interactive editing features for certain data types. Only App Designer apps and figures created with the uifigure function support using table arrays in a Table UI component.

If you are using App Designer to display tabular data, first create aTable UI component in Design View. Then, use the examples on this page to format the data and to set properties of the Table UI component inCode View. For more information about using tables in App Designer, see Add Tables to App Designer Apps.

To see a fully coded example app that uses some of these data types in a table component, see Create Interactive Table in an App.

Numeric Data

In a Table UI component, numeric data displays as right-justified values.

fig = uifigure; tdata = table([10; 1; 5],[12; 7; 38]); uit = uitable(fig,'Data',tdata); uit.Position(3) = 200; uit.RowName = 'numbered';

Table UI component with two columns. Each cell contains a numeric value.

Logical Data

Logical values display as check boxes. true values are checked, whereas false values are unchecked. When the ColumnEditable property of theTable UI component istrue, the user can select and clear the check boxes in the app.

fig = uifigure; tdata = table([true; true; false]); uit = uitable(fig,'Data',tdata); uit.Position(3) = 130; uit.RowName = 'numbered';

Table UI component with one column. Each cell contains a check box. The check boxes in the first two rows are checked, and the check box in the third row is unchecked.

Categorical Data

categorical values can appear as drop-down lists or as text. The categories appear in drop-down lists when theColumnEditable property of theTable UI component istrue. Otherwise, the categories display as text without a drop-down list.

fig = uifigure; cnames = categorical({'Blue';'Red'},{'Blue','Red'}); w = [400; 700]; tdata = table(cnames,w,'VariableNames',{'Color','Wavelength'}); uit = uitable(fig,'Data',tdata,'ColumnEditable',true);

Table UI component. A cell in the "Color" column is selected, and displays a drop-down list with the values "Blue" and "Red".

If the categorical array is not protected, users can add new categories in the running app by typing in the cell.

Datetime Data

datetime values display according to theFormat property of the corresponding table variable (a datetime array).

fig = uifigure; dates = datetime([2016,01,17; 2017,01,20],'Format','MM/dd/uuuu'); m = [10; 9]; tdata = table(dates,m,'VariableNames',{'Date','Measurement'}); uit = uitable(fig,'Data',tdata);

Table UI component with two columns labeled "Date" and "Measurement". The dates in the Date column are formatted as the month, then the day, then the year, separated by forward slashes.

To change the format, use dot notation to set theFormat property of the table variable. Then, replace the data in the Table UI component.

tdata.Date.Format = 'dd/MM/uuuu'; uit.Data = tdata;

Table UI component with two columns labeled "Date" and "Measurement". The dates in the Date column are formatted as the day, then the month, then the year, separated by forward slashes.

When the ColumnEditable property of theTable UI component istrue, users can change date values in the app. When the column is editable, the app expects input values that conform to the Format property of thedatetime array. If the user enters an invalid date, the value displayed in the table isNaT.

Duration Data

duration values display according to theFormat property of the corresponding table variable (a duration array).

fig = uifigure; mtime = duration([0;0],[1;1],[20;30]); dist = [10.51; 10.92]; tdata = table(mtime,dist,'VariableNames',{'Time','Distance'}); uit = uitable(fig,'Data',tdata);

Table UI component with two columns labeled "Time" and "Distance". The data in the "Time" column is displayed in HH:MM:SS format, and the data in the "Distance" column is displayed with four digits after the decimal point.

To change the format, use dot notation to set theFormat property of the table variable.

tdata.Time.Format = 's'; uit.Data = tdata;

Table UI component with two columns labeled "Time" and "Distance". The data in the "Time" column is displayed in seconds, and the data in the "Distance" column is displayed with four digits after the decimal point.

Cells containing duration values are not editable in the running app, even when ColumnEditable of the Table UI component istrue.

Nonscalar Data

Nonscalar values display in the app the same way as they display in the Command Window. For example, this table array contains 3-D arrays and struct arrays.

fig = uifigure; arr = {rand(3,3,3); rand(3,3,3)}; s = {struct; struct}; tdata = table(arr,s,'VariableNames',{'Array','Structure'}); uit = uitable(fig,'Data',tdata);

Table UI component with two columns labeled "Array" and "Structure". Each cell in the "Array" column reads "3x3x3 double" and each cell in the "Structure" column reads "1x1 struct".

A multicolumn table array variable displays as a combined column in the app, just as it does in the Command Window. For example, theRGB variable in this table array is a 3-by-3 array.

n = [1;2;3]; rgbs = [128 122 16; 0 66 155; 255 0 0]; tdata = table(n,rgbs,'VariableNames',{'ROI','RGB'})

tdata =

3×2 table

ROI           RGB       
___    _________________

 1     128    122     16
 2       0     66    155
 3     255      0      0

The Table UI component provides a similar presentation. Selecting an item in the RGB column selects all the subcolumns in that row. The values in the subcolumns are not editable in the running app, even whenColumnEditable property of theTable UI component istrue.

fig = uifigure; uit = uitable(fig,'Data',tdata);

Table UI component with two columns labeled "ROI" and "RGB". The "RGB" column has three subcolumns that hold RGB values.

Missing Data Values

Missing values display as indicators according to the data type:

Missing strings display as<missing>.
Undefined categorical values display as<undefined>.
Invalid or undefined numbers orduration values display asNaN.
Invalid or undefineddatetime values display asNaT.

If the ColumnEditable property of the Table UI component istrue, then the user can correct the values in the running app.

fig = uifigure; sz = categorical([1; 3; 4; 2],1:3,{'Large','Medium','Small'}); num = [NaN; 10; 12; 15]; tdata = table(sz,num,'VariableNames',{'Size','Number'}); uit = uitable(fig,'Data',tdata,'ColumnEditable',true);

Table UI component with two columns labeled "Size" and "Number". One cell in the "Size" column displays "<undefined>", and one cell in the "Number" column displays "NaN". The cell with the "NaN" value is highlighted and editable.