MATLAB: If Statement not working

Question

Hello,

I am new to matlab and have a very, very basic issue. This is a simplified function, but it illustrates the problem I have in my other function.

Matlab seems to bypass my if conditions. Here is the function:

function y = functry(x)
Speed = 100;
if (x> 100)
    Speed = 50;
end
y = Speed * x;
end 

However, the Speed is taken to be 100 even when I input a high range, for example:

y_try = functry(1:150)
plot(1:150, y_try)

Here is still get a linear plot and no change for the Speed when x>100.

Any help would be much appreciated! Thank you!

Answer 1

If x is a vector then the line

if (x> 100)

does not work as expected. The correct syntax is

function y = functry(x)
    Speed1 = 100;
    Speed2 = 50;
    mask = x > 100;
    y = (~mask)*Speed1.*x + mask*Speed2.*x;
end