- All numbers are by default of class type "double" (unless specifically cast as int etc.).
- Logical values are of class "logical".
- Matlab displays 0 (false) and 1 (true) for logical values, but they are not equal to 0 or 1.
- Casting true or false to a number results in a value of 0 or 1
- This is standard convention, casting a logical (or boolean or bool) to a numeric data type results in either 0 or 1 (false or true) and casting a numeric data type as a logical (or boolean or bool) results in false for zero and true for anything else.
Check:
class(1)	% answer = double
class(true)	% answer = logical
When you write
v([0 0 0 0 1 1])
what you are actually saying is [v(0) v(0) v(0) v(0) v(1) v(1)], i.e. you are entering the index locations. For example
v([1 1 1 2 2 1 1 1 2 1 1])	% answer = [1 1 1 2 2 1 1 1 2 1 1];
is perfectly valid!!
You can perform arithmetic with logical values and logic with numeric values, but Matlab automatically casts it as the appropriate class.
Check
class(true + true)	% answer = double
class(v>3)	% answer = logical
class(v.*(v>3))	% answer = double
class(sum(v>3))	% answer = double
logical(5), class(logical(5))	% answer = 1, logical
logical(-5), class(logical(-5))	% answer = 1, logical
logical(0), class(logical(0))	% answer = 0, logical
logical(.1), class(logical(.1))	% answer = 1, logical
Basically logical(~=0)=true and logical(==0)=false, double(true)=1, double(false)=0 but double(1)~=logical(true)!
