Defining function handle from class functions with specific values

Hello all and happy holidays,

I have created a class CustomPL defining a discrete Power Law with parameters beta, ZB and the max number of discrete values. Inside this class, I have created a pdf function depending only on x.

Now I am trying to create a function handle from the main script depending only on beta, ZB and x, but I have not found yet a way to make it work.

Code is as follows:

classdef CustomPL<handle

    properties
        max 
        ZB 
        beta 
        norm 
    end

    methods
        function self = CustomPL(max, ZB, beta)
            self.max = max;
            self.ZB = ZB;
            self.beta = beta;
            self.norm = 0;
            for i=1:max
                self.norm = self.norm + (1/i^beta);
            end
            self.norm = self.norm / (1-ZB);
        end

        function pdf = pdf(self,x)
            assert(floor(x)==x&&x<=self.max);
            if x==0
                pdf = self.ZB;
            else
                pdf = (1/x^self.beta)/self.norm;
            end
        end
    end
end

Now I am trying to create a function handle pdf = @(x,beta,ZB) CustomPL(1000,ZB,beta).pdf(x) but this does not seem to work and I have not found a way around yet. Would you have any idea to get around that?

Many thanks in advance,

Best,

Answer 1

[Steven Lord]

One easy way is to use function notation.

pdf = @(x,beta,ZB) pdf(CustomPL(1000,ZB,beta), x)

You can invoke a method either using dot notation, like object.methodname(...), or using function notation like methodname(object, ...). In almost all circumstances, those will do the same thing. [The documentation gives a description of a circumstance where they won't, but those probably won't apply in this case unless x is an object with certain characteristics or you've overloaded indexing for your object.]

[johnz05]

Thanks Steve, that's of great help but now I can't figure out why this is working and not

    pdf = @(x,beta,ZB) CustomPL(1000,ZB,beta).pdf(x)

as my class definition does not seem to fall in the cases where the dot notation and function notation would work differently. Any idea why? Many thanks. Best

[Steven Lord]

What is the exact full text of the error you receive when you try to either create this anonymous function or call it?