How to write a For function using values from a table ?

My equation is:

y(1) = FOPT -(55930.4 - 330502.*x(1) - 3.18673E6.*x(2) + 344393.*x(3) + 471232.*x(4) + 1.58821E6.*x(5) - 156.186.*x(6));

I want to create a For function and substitute FOPT of a value from a table in the Matlab named FOPT.

Thank you.

Answer 1

[Walter Roberson]

y = NameOfTable.FOPT - (55930.4 - 330502.*x(1) - 3.18673E6.*x(2) + 344393.*x(3) + 471232.*x(4) + 1.58821E6.*x(5) - 156.186.*x(6));

All of the x references are scalars, so the expression in () is a scalar, and a scalar can be subtracted from a matrix without difficulty.

Note: if you are trying to fit parameters against a model, then unless you have strong constraints on your x values, there is not going to be a unique answer, since a change in any one of the x() values can be exactly compensated by a change in another value. For example an increase of 1 in x(1) can be exactly compensated by a decrease of 330502 / 156.186 = 2116.07954618212 in x(6) or an increase of 344393/330502 = 1.04203000284416 in x(3)

[Rami Altam]

Thanks for replaying, yah i got ur point, the thing is I just want the (For function) format so i can substitute FOPT from the table. FYI, i have more than equation and they change with time but i am stuck since I dun know how to write a For function.

[Walter Roberson]

FOPT_values = NameOfTable.FOPT;
num_FOPT = length(FOPT_values);
y = zeros(num_FOPT, 1);
for FOPT_idx = 1 : num_FOPT
  FOPT = FOPT_values(FOPT_idx);
  y(FOPT_idx) = FOPT -(55930.4 - 330502.*x(1) - 3.18673E6.*x(2) + 344393.*x(3) + 471232.*x(4) + 1.58821E6.*x(5) - 156.186.*x(6));
end

... But this is a waste of time, since you can use the simple code

y = NameOfTable.FOPT - (55930.4 - 330502.*x(1) - 3.18673E6.*x(2) + 344393.*x(3) + 471232.*x(4) + 1.58821E6.*x(5) - 156.186.*x(6));

This does substitute FOPT from the table named NameOfTable

https://www.mathworks.com/help/matlab/tables.html

[Rami Altam]

Thank you