MATLAB: Can I pass table as an argument to a function.

Question

Hi,

Currently I am working on migration of MATLAB scripts to C++ code.

I encountered a problem with the datastucture table. Basically I am reading a CSV file using readtable and stored it in a table DataTable. I want to send this table to a function which uses the DataTable for some calculations. But when I tried to access the members of the DataTable this is where the problem starts, The coder app is not allowing me to access the parameters in the DataTable and is showing the error "When indexing a table using variable names, the names of the table variables must be constant.". Example code is below

mycsv.csv is a simple csv file with feilds as X and Y

X,Y

1011,203

1026,210

DataTable = readtable("mycsv.csv");
MyCalulations(DataTable);
function MyCalulations(DataTable)
Xmean=mean(DataTable.X);
Ymean=mean(DataTable.Y)
end

Answer 1

See this answer here: https://www.mathworks.com/matlabcentral/answers/572815-matlab-coder-table-variables-must-be-constant. It will be easier if you index the table using numeric values. For example

function MyCalulations(DataTable)
Xmean=mean(DataTable{:,1});
Ymean=mean(DataTable{:,2})
end

The C++ code is generated correctly.

These are some useful links:

https://www.mathworks.com/help/coder/ug/code-generation-for-tables.html

https://www.mathworks.com/help/simulink/ug/table-limitations-for-code-generation.html