Hi i am trying to replace the content of a SBML file with the content from an excel sheet. I did not write the coding and i therefore have difficulties of understanding what is going on and to fix the eventual Matlab error. I hope i have given enough information.

The excel sheet contains 504 rows and 10 columns (although not all columns are needed)
First row looks like this (columns are separated with : )

RXN_1 : alanine biosynthesis : [c] L-ALPHA-ALANINE -> D-ALANINE : NCgl0563 : alr : amino acid metabolism : 0 : 0 : 1000 : 0

function [CorModel]=createCNW(filename);
% clear all; clc;
RefModel=readCbModel('Ec_iJR904_GlcMM',1000,'SBML');

CorModel = removeRxns(RefModel,char(RefModel.rxns(1:end-1)));
CorModel.genes(1:end-1)='';
CorModel.rxnGeneMat(1:end-1)=[];
CorModel.subSystems='';

% the excel file which contains the information i want to transfer
z='Cor_3.xls';

%from here on the part that i don't understand starts, googling addNum and addTxt doesn't get me anywhere
[addNum, addTxt]=xlsread([z], 'used');

addID=addTxt(:,1);
addForm=addTxt(:,3);
addGRA=addTxt(:,4);
addSub=addTxt(:,6);
addRev=addNum(:,1);
addLB=addNum(:,2);
addUB=addNum(:,3);
addObj=addNum(:,4);

for i=1:length(addID)
CorModel = addReaction(CorModel,addID{i},addForm{i},'',addRev(i),addLB(i),addUB(i),addObj(i),addSub{i},addGRA{i},'','',0);
end

CorModel.metNames=CorModel.mets;
CorModel.metFormulas=CorModel.mets;
CorModel = removeRxns(CorModel,char(CorModel.rxns(1)));
CorModel.genes(1)='';
%CorModel.rxnGeneMat(1)=[];
CorModel.rxns=CorModel.rxns';
CorModel.lb=CorModel.lb;
CorModel.ub=CorModel.ub;
CorModel.c=CorModel.c;

cobraSolverName = 'lp_solve';
cobraSolverName = 'glpk';
LPsolverOK = changeCobraSolver(cobraSolverName, 'LP');

end


The error message from Matlab:

??? Index exceeds matrix dimensions.

Error in ==> createCglutNW at 24
addGRA=addTxt(:,4);


If i exchange the columns here from
addGRA=addTxt(:,4);
addSub=addTxt(:,6);

to

addGRA=addTxt(:,2);
addSub=addTxt(:,2);

then Matlab does the job (it is of course wrong because i don't want to use the column 2, but 4 and 6)

Hope somebody can see where it is going wrong