Matlab can't change parameters of a class while in constructor

I am calling a function to change parameters of my class inside its constructor, however, I can't change the values. Is this a bug or on purpose?

In the following example, I am calling function "calculateCalculatedProperties()" inside constructor. "calculateCalculatedProperties()" calls "Velocity()" and "Length()" function which sets new values of velocity and length properties. However, at the end product of the constructor (object instance) properties are unchanged.

classdef piping
    %PIPING Summary of this class goes here
    %   Detailed explanation goes here
    
    properties 
        flowRate
        diameter
        startLocation location
        endLocation location
    end

    
    
    methods
        function self = piping(flowRate, diameter, startLocation, endLocation)
            
            self.flowRate = flowRate;
            self.diameter = diameter;
            self.startLocation = startLocation;
            self.endLocation = endLocation;
            
            self.calculateCalculatedProperties();
                       
        end
        
        function self = calculateCalculatedProperties(self)
            fprintf("hey")
            self.Velocity();
            self.Length();
        end
        
        
         function self = Velocity(self)
             self.velocity = self.flowRate / (pi * self.diameter^2 / 4);
         end
        
         function self = Length(self)
            self.length = location.calculateDistance(self.startLocation,self.endLocation) ;
            fprintf("hey this is lengthhhh")
            self.flowRate = 10000000;
         end

        
    end
    
    properties % Calculated properties
        
        velocity
        length
    end
end

Solution

The issue here is that you are using a value class, not a handle class. Note that in your Velocity method you are returning an instance of "self", in a value class these method invocations return a separate object, which is being ignored in this code.

That being said two possible solutions:

Capture output of value objects and return the final, modified object.

 function self = piping(flowRate, diameter, startLocation, endLocation)
     % ...
     self = self.calculateCalculatedProperties();      
 end

 function self = calculateCalculatedProperties(self)
     fprintf("hey")
     self = self.Velocity();
     self = self.Length();
 end

Use handle classes to create a mutable object.
```
 classdef piping < handle
     % ...
 end
```

See Comparison of Handle and Value Classes for more info.