Plotting for a range of values

mA = 10;
muA = 0.3;
muB = 0.1;
g = 9.81;
theta = 30;
NA = mA*g*cosd(theta);
NB = mB*g*cosd(theta);
for mB = [1:1:20]
    a = ((mA)*(g)*(sind(theta)) - (muA)*(NA) + (mB)*(g)*(sind(theta)) - (muB)*(NB)) / (mA + mB)
end
plot(mB,a)

The graph is not showing a curve and the x-axis values are incorrect. Quite new to matlab, but I have used a for loop in order to gain multiple values for 'a' when mB ranges from 1-20 in increments of 1. Could anyone help?

Thank you

Answer 1

[Geoff Hayes]

Verdan - in your code, the mB and a are scalars whereas you want them to be arrays (for when you plot outside of the loop). Try doing

xData = 1:1:20;
a = size(xData);
for mB = xData
    NB = mB*g*cosd(theta); % I moved this here since it depends upon mB
    a(mB) = ((mA)*(g)*(sind(theta)) - (muA)*(NA) + (mB)*(g)*(sind(theta)) - (muB)*(NB)) / (mA + mB);
end
plot(xData,a);