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How to set a let to display a numerical value in App Design?

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Adil Ali
Adil Ali 2019-12-5
评论： Rik 2019-12-5
I recently migrated my gui from guide to app design. Everything was working prior to the move. one last (hopefully) issue i am facing is updating the text on a label to a numberical value returned by numel() function.
error is :
Error using matlab.ui.control.internal.model.mixin.MultilineTextComponent/set.Text (line 49)
'Text' must be a character vector, or a 1-D array of the following type: cell array of character vectors, string, or categorical.
The code :
while strcmp(value,'On')
[plyX, plyY] = ginput(2); %% prompt the user to click two points. (Care needs to be taken to fist click the lower left corner and then select upper right corner)
width = abs(plyX(1) - plyX(2)); %%Compute width
height = abs(plyY(1) - plyY(2)); %%Compute height
rec = rectangle('Position',[plyX(1) plyY(1) width height]);
[in,on] = inpolygon(app.X,app.Y,plyX,plyY);
inon = in | on; %%Ammend point in and on the edge of the rectangle
idx = inon(:); %%get all the indeces of the points in the polygon
% [ptsx get_in]=numpoints(plyX,plyY,laser1_pts); %%using numpoints function just for comparison
xcoord = app.X(idx); %%get the X coordinates of the poits in the polygon
PointsInSelection = numel(xcoord); %%get the number of points
% PointsInSelection2 = get_in; %%get the number of points
app.Label.Text = PointsInSelection;
% display(handles.PointsInSelection2);
pause(3);
delete(rec);
end

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采纳的回答

Adil Ali
Adil Ali 2019-12-5
I used
app.Label.Text = string(numericalValue);
compared to
app.Label.Text = numericalValue;
And it worked!
Not sure why App design had to make things complicated! it is so simple to code without it. Its almost like programming in Java!
  1 个评论
Rik
Rik 2019-12-5
Just like all other parts of Matlab: it matters what the data type is. You can't mix up the value of a variable and the representation of that value in a character vector or string scalar
v1=10;
v2='10';
v3="10";
%all 3 are different (although v2 and v3 are similar in many ways)

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