In App Designer: put new data into a (ui)table

This should be easy... Data comes in from a serial device consisting of a character and a number (time in msec) and I want to insert it into a table on screen.

I've got my serial callback working (after much effort) and I thought the next step would be easier. I have created a uitable that is displayed on the screen. Empty at first, called ResultsTable and thus referred to as app.ResultsTable with 2 columns named 'Event' and 'Time'. Everything else about the table is defaulted.

The app.ResultsTable.Data is initially [ ] as expected and as each bit of info comes in I want to add it to the table. Serial callback parsed the input into PType (a character) and PTime (uint32) so why does

app.ResultsTable.Data(app.NextTrial,'Event') = char(PType);
app.ResultsTable.Data(app.NextTrial,'Time') = PData;

Give me multiple columns where the number of columns is the ascii value of the character? If PType is 'A' I get 64 zeros and then a 65. I've tried various combinations of [ PType PData ] ( etc.) { another attempt }. All kinds of complicated merging of multiple tables is described in help but not simply putting new data into a new table within App Designer code (which has to be different than MatLab of course)

And after I get that first row in, I sure hope I can keep adding rows (app.NextTrial is the row index of course) for as long as I have enough memory (maybe 1000 rows?), that I can later export to an excel file or .CSV.

Thanks for the help for an old time C coder new to Matlab.

[Gavin]

BTW I have assigned numbers from one table to another with this syntax e.g.

app.TrialsTable(ii, 2) =  app.StimInputTable.Data(jj,3);

And it works just fine.... Even fun things like this work

app.TrialsTable.Var3(ii+xx) = LRCat(1);

While waiting for answers... I tried setting types for the columns with

app.ResultTable = setvartype(app.ResultTable, ...
    {'Event','Time'},{'char','uint32'});

But I got

Undefined function 'setvartype' for input arguments of type 'matlab.ui.control.Table'.

Adding .Data just gives me

Undefined function 'setvartype' for input arguments of type 'cell'.

[Gavin]

I finally hit on something that works. Wouldn't hurt to document simple example like this inTable halp.

app.ResultsTable.Data(end+1,:) = [PType,PData];

remaining problem is that even though PType is a char the table shows a number

app.ResultsTable.Data = setvartype(app.ResultsTable.Data, {'Event','Time'},{'char','uint32'});

or

app.ResultsTable = setvartype(app.ResultsTable,{'Event','Time'},{'char','uint32'})

Gives Incorrect number or types of inputs or outputs for function setvartype.

Example in Help

opts = setvartype(opts,{'LastName','Gender','Location',...

'Smoker','SelfAssessedHealthStatus'},'string');

So I tried

app.ResultsTable.ColumnFormat {'char','uint32'}

Index in position 1 exceeds array bounds.

I thought I was on the right track since

app.ResultsTable.ColumnName

ans =

2×1 cell array

{'Event'}

{'Time' }

and

K>> app.ResultsTable.ColumnFormat

ans =

0×0 empty cell array

More help searching on cell array... try

K>> C = {'char', 'uint32'}

C =

1×2 cell array

{'char'} {'uint32'}

K>> app.ResultsTable.ColumnFormat = C

Error setting property 'ColumnFormat' of class 'Table':

ColumnFormat definitions must be either 'numeric', 'logical', 'char', 'short', 'long', 'short e',

'long e', 'short g', 'long g', 'short eng', 'long eng', 'bank', '+', 'rat' or be a popupmenu

definition

OK so no uint32 allowed, now you tell me!

K>> C = {'char', 'long'}

app.ResultsTable.ColumnFormat = C

ans =

1×2 cell array

{'char'} {'long'}

So obvious (NOT!) why didn't I think of that first. At least no error but then again it doesn't work

76 63383

76 64298

76 65535

82 65535

How long is long? where is my char?

[Mario Malic]

  app.ResultsTable.Data(end+1,:) = [PType,PData];

This is one of the first thing you learn, when you learn MATLAB. It wouldn't hurt if you went over MATLAB Onramp quickly, takes 30-60 mins IIRC.

[Gavin]

i thought I'd go ahead and do the course but I got this:

Course Overview >Course Overview

HTTP ERROR 431 Request Header Fields Too Large

URI:/R2024a/videoPage.html?caption=on&lang=en&videoIdUrl=6084985398001&isLocalized=false&volume=1&play=false&darkMode=falseSTATUS:431MESSAGE:Request Header Fields Too Large

Answer 1

[Mario Malic]

Hi Gavin,

Hopefully, I understood the question and here's an example code that could help.

hFig = uifigure();
t = uitable("Parent", hFig);
pType = 'a';
pData = 1;

pType = convertCharsToStrings(pType); % uitable supports string arrays, not char arrays
for i = 1 : 5
    if isempty(t.Data) % Init (sets the var types too)
        t.Data = [pType, pData];
    else
        t.Data(end + 1, :) = [pType, pData]; % adding data to the next row
    end
    pData = pData + 1;
end

[Gavin]

Thank you, that took care of it. The isempty() part is necessary or it puts the first one in as NAN. If one isn't changing types it's not necessary.

I come from the world of C, C++ and other strongly typed languages. MatLab's weak typing causes more troubles than is solves IMO.