getting an error in this code

clc
clear 
%shipcostpmf.m



sx = (1:8);
px = [0.15*ones(4,1), 0.1*ones(4,1)];
gx = (sx<=5).*(105*sx-5*(sx.^2)) + ((sx>5).*500);

sy = unique(gx);
fprintf('sy =\n');
disp(sy);
py = finitepmf(gx,px,sy);

not sure why my py is getting an error because it says Unrecognized function or variable 'finitepmf'. but finitepmf should be a command?

Answer 1

[Mahmoud Ashraf]

you should define funstion of finitrepmf

as shown in this code

clc
clear 
%shipcostpmf.m
sx = (1:8);
px = [0.15*ones(4,1), 0.1*ones(4,1)];
gx = (sx<=5).*(105*sx-5*(sx.^2)) + ((sx>5).*500);
sy = unique(gx);
fprintf('sy =\n');
disp(sy);
py = finitepmf(gx,px,sy);


function pmf=finitepmf(sx,px,x) 
% finite random variable X: 
% vector sx of sample space 
% elements {sx(1),sx(2), ...} 
% vector px of probabilities 
% px(i)=P[X=sx(i)] 
% Output is the vector 
% pmf: pmf(i)=P[X=x(i)] 
    pmf=zeros(size(x(:))); 
    for i=1:length(x) 
        pmf(i)= sum(px(find(sx==x(i)))); 
    end
end

Answer 2

[Voss]

Maybe finitepmf should be defined as follows:

function pmf=finitepmf(sx,px,x) 
% finite random variable X: 
% vector sx of sample space 
% elements {sx(1),sx(2), ...} 
% vector px of probabilities 
% px(i)=P[X=sx(i)] 
% Output is the vector 
% pmf: pmf(i)=P[X=x(i)] 
    pmf=zeros(size(x(:))); 
    for i=1:length(x) 
        pmf(i)= sum(px(find(sx==x(i)))); 
    end
end

which was found here:

https://www.mathworks.com/matlabcentral/answers/627263-how-to-find-probability-mass-function

If that seems right and you haven't done so already, put that code into an m-file called finitepmf.m. If you have done that already, then make sure that finitepmf.m is on your MATLAB search path.

Answer 3

[Mathieu NOE]

hi

here you are

sx = (1:8);
px = [0.15*ones(4,1), 0.1*ones(4,1)];
gx = (sx<=5).*(105*sx-5*(sx.^2)) + ((sx>5).*500);
sy = unique(gx);
fprintf('sy =\n');
disp(sy);
py = finitepmf(gx,px,sy)


function pmf=finitepmf(sx,px,x) 
% finite random variable X: 
% vector sx of sample space 
% elements {sx(1),sx(2), ...} 
% vector px of probabilities 
% px(i)=P[X=sx(i)] 
% Output is the vector 
% pmf: pmf(i)=P[X=x(i)] 
    pmf=zeros(size(x(:))); 
    for i=1:length(x) 
        pmf(i)= sum(px(sx==x(i))); 
    end
end