Trouble with Matrix Dimensions

I am trying to simulate the kinematics of a crank slider in matlab. I have obtained a function which I believe to be correct, however matlab gives me this error:

>> velx = -r*sin(a) - L*(asin((r/L)*sin(a)))*(acos(((r/L)*sin(a))*((r/L)*sin(a))))

Error using *

Inner matrix dimensions must agree.

The variable 'a' is a 1x100 matrix generated via the linspace command. r and L are simply 1x1 single digit numbers. How can I get around this error? I want to plot the output of velx vs 'a' to obtain a graph.

It works if 'a' is just a 1x1 number, but doing it this way would require me to manually type in the values for 'a' 100 times and this would be tedious. I think perhaps there is a way to do it with a for loop command?

If anyone could help it would be much appreciated.

Answer 1

[Azzi Abdelmalek]

Use operation element by element .*

velx = -r*sin(a) - L*(asin((r/L)*sin(a))).*(acos(((r/L)*sin(a)).*((r/L)*sin(a))))

[Patrick]

Thanks man, you're a life saver