How to get a function to accept a vector as input?

I'm trying to write a function that takes multiple variables in

function [x] = classproj(W, k1, k2, d)
%UNTITLED4 Summary of this function goes here
%   Detailed explanation goes here


if W.*(1./k1) < d
    x = W.*(1/k1);

elseif W.*(1/k1) >= d
    x = (W + 2*k2*d).*(1./(k1+2*k2));
end
end

This works if all variables are scalar, but if I try to make W a vector it results in an error claiming that x is not assigned during call

Answer 1

[Stephan]

Hi,

no if-else is needed, when using logical indexing:

function [x] = classproj(W, k1, k2, d)
x(W.*(1/k1)<d) = W(W.*(1/k1)<d).*(1./k1);
x(W.*(1/k1)>=d) = (W(W.*(1/k1)>=d) + 2*k2*d).*(1./(k1+2*k2));
end

Best regards

Stephan

[Kevin Phung]

@Aaron Taub Stephan's answer will actually solve your dilemma, so I'll remove mine and would like to add a bit as to why your code didn't work:

if W is a vector, then you will have logical arrays for your if and elseif conditions.

for example, if i had:

x = 1:5
if x<3
    %insert some code here
end

the inside of this if-statement would never run because it will be evaluating a logical array of

' 1 1 0 0 0'

When it is only supposed to be evaluating logical scalars (one value, either 1 or 0)