Making a new function with code

Hi guys,

im trying to make a new function called poweroutput with code that has been used before in different task, im confused on how i would convert this code into a function so it can be used for a differnet task, in the new function i should be able to change the inputs of the variables.

[Stephen23]

Original question by Sebastion Sunny retrieved from Google Cache:

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https://web.archive.org/web/20211210124925/https://www.mathworks.com/matlabcentral/answers/1607205-making-a-new-function-with-code

Making a new function with code

Hi guys,

im trying to make a new function called poweroutput with code that has been used before in different task, im confused on how i would convert this code into a function so it can be used for a differnet task, in the new function i should be able to change the inputs of the variables Windspeeds,Cd and deltaT:

clear
close all
%vairables defined
Cp = 0.335;
Ct = 0.042;
Vrated = 11.5; %m/s 
Vcutin = 3;  %m/s
Vcutout = 25; %m/s
D = 171;
k = 6e6;
j = 100e5;
%Create wind,time and rotational speed variables
deltaT = 0.01;
time = 0:deltaT:300;
WindSpeeds = linspace(0,30,length(time));%m/s
%preallocation
rotorTorque = zeros(length(WindSpeeds),1); %Nm
turbinePower = zeros(length(WindSpeeds),1);
generatorTorque = zeros(length(WindSpeeds),1);
omegaRotor = zeros(length(WindSpeeds),1);
%eulers method
for i = 2:length(time)
    rotorTorque(i) = windTurbineRotorModel(WindSpeeds(i),Ct,D,Vcutout,Vrated,Vcutin);
    omegaRotor(i) = omegaRotor(i-1)+deltaT*(rotorTorque(i)-generatorTorque(i-1)-(Cd*(omegaRotor)))/j;
    turbinePower(i) = omegaRotor(i)*rotorTorque(i);
    generatorTorque(i) = k * omegaRotor(i).^2;
end
figure;
plot(WindSpeeds,turbinePower/1000)
ylabel('TurbinePower kW')
hold on
yyaxis right
plot(WindSpeeds,generatorTorque/1000)
hold on
plot(WindSpeeds,rotorTorque/1000)

Thank you

Answer 1

[Voss]

function poweroutput(Windspeeds,Cd,deltaT)

%vairables defined
Cp = 0.335;
Ct = 0.042;
Vrated = 11.5; %m/s 
Vcutin = 3;  %m/s
Vcutout = 25; %m/s
D = 171;
k = 6e6;
j = 100e5;

% since Windspeeds and time need to be the same size, build the variable
% time from the input arguments Windspeeds and deltaT:
% time starts at 0, has spacing deltaT, and has the same number of elements
% as windSpeeds
% note: maximum time is no longer necessarily 300
time = deltaT*(0:numel(Windspeeds)-1);

%Create wind,time and rotational speed variables
% deltaT = 0.01;
% time = 0:deltaT:300;
% WindSpeeds = linspace(0,30,length(time));%m/s

%preallocation
rotorTorque = zeros(length(WindSpeeds),1); %Nm
turbinePower = zeros(length(WindSpeeds),1);
generatorTorque = zeros(length(WindSpeeds),1);
omegaRotor = zeros(length(WindSpeeds),1);
%eulers method
for i = 2:length(time)
    rotorTorque(i) = windTurbineRotorModel(WindSpeeds(i),Ct,D,Vcutout,Vrated,Vcutin);
    omegaRotor(i) = omegaRotor(i-1)+deltaT*(rotorTorque(i)-generatorTorque(i-1)-(Cd*(omegaRotor)))/j;
    turbinePower(i) = omegaRotor(i)*rotorTorque(i);
    generatorTorque(i) = k * omegaRotor(i).^2;
end
figure;
plot(WindSpeeds,turbinePower/1000)
ylabel('TurbinePower kW')
hold on
yyaxis right
plot(WindSpeeds,generatorTorque/1000)
hold on
plot(WindSpeeds,rotorTorque/1000)

end

[Sebastian Sunny]

Ahh thank you that makes more sense