E+ and Matlab Error - Error using table (line 335) 'XOutputNameX' is longer than the maximum allowed length for a table variable name.

Hi everyone!,

I am trying to performe a co-simulation between E+ and Matlab using the "EnergyPlus Co-simulation Toolbox" and I tried to an output and the error bellow appears.

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Error using table (line 335)

'EP_ZN__Refrigeration_Air_Chiller_System_Total_Compressor_Electric_Energy'

is longer than the maximum allowed length for a

table variable name.

Error in mlepMatlab_example (line 41)

logTable = table('Size',[0, 1 + ep.nOut],...

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This is line 41 :

nRows = ceil(endTime / ep.timestep); %Query timestep after mlep initialization
logTable = table('Size',[0, 1 + ep.nOut],...
    'VariableTypes',repmat({'double'},1,1 + ep.nOut),...
    'VariableNames',[{'Time'}; ep.outputSigName]);
iLog = 1;

How can I solve this problem ?

Answer 1

[Steven Lord]

The maximum length a table variable name may have in MATLAB is namelengthmax.

namelengthmax

ans = 63

The name you're trying to use has length:

strlength('EP_ZN__Refrigeration_Air_Chiller_System_Total_Compressor_Electric_Energy')

ans = 72

You will need to use a shorter name, perhaps by abbreviating Refrigeration to Fridge and Electric to Elec?

strlength('EP_ZN__Fridge_Air_Chiller_System_Total_Compressor_Elec_Energy')

ans = 61

[Zakaria OUAOUJA]

Thank you @Steven Lord for your comment.

The output variable name is defined by EnergyPlus and I can not change it.

Is there any way to change it when imported to MATLAB.

% Prepare data logging

nRows = ceil(endTime / ep.timestep); %Query timestep after mlep initialization

% Logging Table

logTable = table('Size',[0, 1 + ep.nOut],...

'VariableTypes',repmat({'double'},1,1 + ep.nOut),...

'VariableNames',[{'Time'}; ep.outputSigName]);