Logical indexing: More than two conditions

Say,I have a vector of x, and each particular x that according to the rule 1) less than zero, 2) greater than zero, and 3) equal to 2, will satisfy different equation. I know, by using simple IF-Else condition, we can have the framework as below. x = rand(-3,3)

Case 1

if x > 0 y=x^3 elseif x < 0 y=x^2 elseif x = 2 y = x else

However, I am interested to use the logical indexing. I know, for a two conditions, the arrangement such that

Case 2

cond1 = (x > 0) | (x < 0) y = cond1.*(x^3) + ~cond1.*(x^2);

Thus, using the same logic, I tried to modified the above logical indexing to fit the 3 conditions such as

Case 3

cond1 = (x > 0) | (x < 0) | (x == 2) y = cond1.*(x^3) + ~cond1.*(x^2)+ ~cond1.*(2); y = cond1.*(x^3) + ~cond1.*(x^2);

However, I am not able to produce accurate result for the Case 3, any idea how to implement logical-indexing for more than 2 conditions.

Thanks in advance

Answer 1

[Mischa Kim]

Do you mean

 x = -10:10;
 y = (x>=0 & x~=2).*x.^3 + (x<0).*x.^2 + (x==2).*x

[balandong]

Hi Mischa, Although different from the syntax such as in Case 2 and Case 3, but your suggested code does the trick. Thanks for the quick response.