Looping through a column of data from start to end

I need to loop through a column data set from start to end so I can calculate an equation.

The equation is given below. Gamma is a known value. CA, P_Pa, V_m3 are all given data that is sorted in a column. The issue that I am having is that when Q_dot_net is solved for, it only gives one value across the whole table. Q_dot_net should be changing based on the data. I am pretty sure this value is calculated from the last two data points in the set.

% read in the cylinder pressure from the excel file
[data] = xlsread('PressureME469.xlsx','PME469');

% split the data into CA and Pressure vectors
CA = data(:,1);     % crank angle (deg. ATDC)
P = data(:,2);      % cylinder pressure (bar)
P_Pa = P*1e5        % cylinder pressure converstion from bar to Pascal (Pa)
nCA = length(CA);   % number of pressure points recorded

for i = 1:length(P_Pa);
    for n = 1:length(CA);
        for m = 1:length(V_m3);
            Q_dot_net(n) = gamma/(gamma-1).*i.*(m-(m-1))/(n-(n-1)) + 1/(gamma-1) + m.*(i-(i-1))/(n-(n-1));
        end
    end
end
Q_dot_net = Q_dot_net.';

[Mathieu NOE]

hello

there is something disturbing me here

I don't get why Q_dot_net is indexed by n only and why the two extra for loops involving i and m ....

maybe sharing also the excel file could be helpful and some more explanation about what size should be Q_dot_net

[Drew ARNDT]

I ended getting this to work. There were two extra loops here that were unneccessary

% read in the cylinder pressure from the excel file

[data] = xlsread('PressureME469.xlsx','PME469');

% split the data into CA and Pressure vectors

CA = data(:,1); % crank angle (deg. ATDC)

P = data(:,2); % cylinder pressure (bar)

P_Pa = P*1e5 % cylinder pressure converstion from bar to Pascal (Pa)

nCA = length(CA); % number of pressure points recorded

for i = 2:2880

Q_dot_net(i) = gamma/(gamma-1)*P_Pa(i)*(V_m3(i)-V_m3(i-1))/(CA(i)-CA(i-1)) + 1/(gamma-1) *V_m3(i)*(P_Pa(i)-P_Pa(i-1))/(CA(i)-CA(i-1));

end

Q_dot_net = Q_dot_net.';

This ended up solving the equation for what I needed

[Mathieu NOE]

yes , that was more or less what I would have expected !