how can i make matlab select a value for a vector variable from a set of data

i am doing optimization design model that compare the fuel consumption of different diesel engines.

so, i have excel sheet contains the MCR of different diesel engines from manufactureres.
i have defined a variable MCR and i want matlab to assign a value for MCR from the values of MCR data that stored in excel sheet
i want that to be done automatically every time the optimization algorithm run a new attempt.
what is the function i should use to assign the value of MCR from the created set of data?

Answer 1

[darova]

Use xlsread

MCRdata = xlsread('data.xls');      % read data from excel file
MCR0 = MCRdata(5);                  % assign 5th value

[Nourhan Elsayed]

thank you Darova for your answer

i tried this function but i dont think it is suitable because MCR is a vector variable size:1xm

MCR = MCR1 MCR2 MCR3 ....MCRm

i want matlab to assign a value for each MCR , randomly, from the excel datasheet.

[darova]

Can you show an example? I don't understand

[Nourhan Elsayed]

my model has the following variables

m = 3;  % ''for examble'' m is the number of installed main engines per one propulsion train
j = 4 % ''for examble'' j number of modes of operation
x = sym ('x', [m j]); %x is the loading of main engine number m at j mode of operation 
assume (x >= 0);
assumeAlso (x<=1);

thus, x is a symbolic matrix variable of size m x j

i have used this function to define MCR as an array of size 1x3

 MCR = sym('MCR', [1 m]) % MCR of engine with index m

and the below function defines MCR data set

 MCRdata = [250; 450;1500;900;2500;2000;1750] 

my objective is to make the model choose a value for MCR from the MCRdata, no matter the order. Then, this value of MCR goes through a series of functions and calculations later on.

So, MCR is a symbolic variable whos value is assigned automatically from a defined MCRdata

[darova]

What about this trick?

MCRdata = [250; 450;1500;900;2500;2000;1750];
ix = randi(length(MCRdata),1,length(MCR));
MCR = sym( MCRdata(ix) );
[ix' MCR]