calling a callback function from script

hello everyone,

I am trying to calculate the steam table data using the XSteam.m script. I have written a callback loop to calculate the density of the steam at perticular temperature and pressure values. the function is as follows.

where a is the final pressure

When i am trying to run the script it gives an error as

Error using zeros

Maximum variable size allowed by the program is exceeded.

Error in Untitled2 (line 5)

y = zeros(1:((a-1)/b));

Please check the script and help me with it.

With regards.

a = 10;
b = 0.01;
T = 200;

y = zeros(1:((a-1)/b));
L = length(y);

for i = 0:L
    p(i)= 1+b*i;
    y(i) =XSteam('rho_pT',i,T);
end

[Stephen23]

This code

zeros(1:((a-1)/b))

defines an array with size

zeros(1,2,3,4,5,6,7,8,9,10,11,...,900)  

which would require so much memory that it can't even be calculated using double numeric class. Impressive, but unlikely to be very useful. Perhaps you meant:

zeros(1,((a-1)/b));
%      ^ comma

Answer 1

[JESUS DAVID ARIZA ROYETH]

is y = zeros(1,((a-1)/b)); you have ":" instead of a ","

a = 10;
b = 0.01;
T = 200;
y = zeros(1,((a-1)/b));
L = length(y);
for i = 1:L
    p(i)= 1+b*i;
    y(i) =XSteam('rho_pT',i,T);
end

[vishnuvardhan naidu tanga]

I have used that and then it says the following

Array indices must be positive integers or logical values.

Error in enthalpyliq (line 9)

p(i)= 1+b*i;

[Steven Lord]

There's no such thing as element 0 in an array in MATLAB. The first element of p is p(1) not p(0).

In this case there's no need to create p inside the for loop.

p = 1 + b*(0:L);

I don't know whether your XSteam function can accept a vector of values as its second input. If it can (and returns a vector the same size as that second input, where each element of the output is the result of operating on the corresponding element of that second input) you could eliminate the loop altogether.

y = XSteam('rho_pT', 0:L, T);

[vishnuvardhan naidu tanga]

no, the function can not give an vector output. It only gives scalar outputs, and when I try this

p = 1 + b*(0:L);

all the values are turn to zero and i have used p(1).