perform operations next to a string in matlab - string

Question

I have my data coming back as a cell which looks like this (each trade is underneath each other in the cell ie its a 5 by 4 cell):
sell 50 FTSE 6500
buy 100 Eurostoxx 3300
buy 25 SP 1980
buy 30 FTSE 6490
sell 25 Eurostoxx 3315
Firstly because I have mixed data its coming back from my database query as a cell so not sure if thats a problem
What I'd like to do is mark these to market, so I have closing market price of each of these contracts as a variable lets call them FTSE_CLOSE, EUROSTOXX_CLOSE and SP_CLOSE.
I'd like to be able to do something that goes as follows:
where coloumn 3 = "FTSE" and column 1 = "sell" then column 5 = column2 * (column4 - FTSE_CLOSE)
where column 3 = "FTSE" and column 1 = "buy" then column 5 = column2 * (FTSE_CLOSE - column4)
and so on for the other contracts.
Basically I am struggling with the mixed use of strings and numbers
Do I need to cell2mat everything so I have several vectors and then somehow look into the string vectors and perform the calucaltion on the other relevant vectors i.e. quantity * price - close_price
Is there a simpler way of doing this

Answer 1

I think you are simply looking for the command str2num
Here is one idea:
input_data={"sell","50","FTSE","6500";
"buy","100","Eurostoxx","3300";
"buy","25","SP","1980",
"buy","30","FTSE","6490",
"sell","25","Eurostoxx","3315"};
closing_price.FTSE=6000;
closing_price.Eurostoxx=3000;
closing_price.SP=2000;
for i=1:size(input_data,1)
if strcmp(input_data{i,1},'sell')
diff_from_market(i)=str2num(input_data{i,2}) ...
*(str2num(input_data{i,4})-closing_price.(input_data{i,3}));
elseif strcmp(input_data{i,1},'buy')
diff_from_market(i)=str2num(input_data{i,2}) ...
*(closing_price.(input_data{i,3})-str2num(input_data{i,4}));
end
end
diff_from_market