MATLAB: How to make this code more efficient

efficientshortshortentoolong

So I'm a bit of a noob with matlab and I'm not very efficient with my code writing, below is one of my scripts that gets the job done however it just seems…long and not very efficient at all which is an issue because I'll have multiple scripts that will follow this bad habit until a new method comes forward, can anyway help me condense this code?
%constants
ConrodLength=0.1375; %m


Stroke=0.082; %m
Throw=0.041; %m
PistonMass=0.28866; %Kg
CrankAngle=(-360:1:359)'; %Degrees
CrankAngleRad=deg2rad(CrankAngle); %Radians
%Angular velocity
w=[104.7198;130.8997;157.0796;183.2596;209.4395;235.6194;261.7994;314.1593;366.5191;418.879;471.2389;523.5988;575.9587;575.9587;628.3185;680.6784];
%Inertia
for i=CrankAngleRad
        acc1=Throw*(w(1)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(1)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia1000=PistonMass*acct;
        figure
        subplot(1,1,1)
        plot(CrankAngle,Inertia1000)
        title('Inertia/Crank Angle')
        xlabel('Crank Angle (degrees)')
        ylabel('Inertia (Kg rad/s^2)')
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(2)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(2)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia1250=PistonMass*acct;
        plot(CrankAngle,Inertia1250)
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(3)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(3)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia1500=PistonMass*acct;
        plot(CrankAngle,Inertia1500)
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(4)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(4)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia1750=PistonMass*acct;
        plot(CrankAngle,Inertia1750)
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(5)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(5)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia2000=PistonMass*acct;
        plot(CrankAngle,Inertia2000)
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(6)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(6)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia2250=PistonMass*acct;
        plot(CrankAngle,Inertia2250)
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(7)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(7)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia2500=PistonMass*acct;
        plot(CrankAngle,Inertia2500)
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(8)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(8)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia3000=PistonMass*acct;
        plot(CrankAngle,Inertia3000)
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(9)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(9)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia3500=PistonMass*acct;
        plot(CrankAngle,Inertia3500)
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(10)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(10)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia4000=PistonMass*acct;
        plot(CrankAngle,Inertia4000)
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(11)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(11)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia4500=PistonMass*acct;
        plot(CrankAngle,Inertia4500)
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(12)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(12)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia5000=PistonMass*acct;
        plot(CrankAngle,Inertia5000)
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(13)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(13)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia5500=PistonMass*acct;
        plot(CrankAngle,Inertia5500)
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(14)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(14)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia6000=PistonMass*acct;
        plot(CrankAngle,Inertia6000)
        hold on
end
for i=CrankAngleRad
        acc1=Throw*(w(15)^2)*cos(i);
        acc2=(Throw/ConrodLength)*Throw*(w(15)^2)*cos(2*i);
        acct=acc1+acc2;
        Inertia6500=PistonMass*acct;
        plot(CrankAngle,Inertia6500)
        hold on
end
hold off

Best Answer

You can take advantage of the bsxfun function to do all the matrix multiplications at once. Then do the scalar multiplications and plot the results.
See if this does what you want:
%constants
ConrodLength=0.1375; %m


Stroke=0.082; %m
Throw=0.041; %m
PistonMass=0.28866; %Kg
CrankAngle=(-360:1:359)'; %Degrees
CrankAngleRad=deg2rad(CrankAngle); %Radians
%Angular velocity
w=[104.7198;130.8997;157.0796;183.2596;209.4395;235.6194;261.7994;314.1593;366.5191;418.879;471.2389;523.5988;575.9587;575.9587;628.3185;680.6784];
acc1 = Throw * bsxfun(@times, w.^2, cos(CrankAngleRad)');
acc2 = Throw^2/ConrodLength * bsxfun(@times, w.^2, cos(2*CrankAngleRad)');
acct = acc1 + acc2;
Inertia = PistonMass * acct;
figure(1)
plot(CrankAngle, Inertia)
title('Inertia/Crank Angle')
xlabel('Crank Angle (degrees)')
ylabel('Inertia (Kg rad/s^2)')
I didn’t time it, although I’d be surprised if it wasn’t significantly faster. The plot looks the same to me as your original code produced.
—————
EDIT — Thinking about this further, even the bsxfun calls aren’t necessary. Straightforward vector multiplication creates the required matrices:
acc1 = Throw * (w.^2 * cos(CrankAngleRad)');
acc2 = Throw^2/ConrodLength * (w.^2 * cos(2*CrankAngleRad)');
This is likely even faster.
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