I get the following error message: "'Value' must be a double scalar." in appdesigner
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In my appdesigner code I want to get some values from my excel sheet (these values depend on the choice of the list box item):
if value == '2'
F = readtable("CO2_neu.xlsx","Sheet","List","Range","E4");
app.weight_1.Value = double(F.(1));
...
elseif value == '7'
G = readtable("CO2_neu.xlsx","Sheet","List","Range","E9");
app.weight_1.Value = double(G.(1));
end
For the value in cell E9 everything works and the respective value is displayed in my app. For all the other values from E4 - E8 I get the error message: 'Value' must be a double scalar even though these are also just numbers that I entered into the excel sheet and I use the exact same code to get them. Here you can see the excel sheet.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/1437368/image.png)
As the code works for the value in E9, I don't understand what the error is for the other cells?
I would be really grateful if someone could help me to fix this error!
1 Comment
Stephen23
on 19 Jul 2023
Edited: Stephen23
on 19 Jul 2023
Rather than using EQ to compare text like this:
if value == '2'
I strongly recommend that you use STRCMP or something similar. Or even SWITCH. Note that you could anyway replace that entire IF/ELSEIF... by defining the Range in terms of that value. Perhaps something like this:
N = 2;
R = "E"+(N+2);
T = readtable("CO2_neu.xlsx","Sheet","List","Range",R)
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