May i know why i can't write: while(N~=[0 0 0]) in matlab?

N is a 1x3 array

Answer 1

[Walter Roberson]

while (N~=[0 0 0])

is valid syntax in MATLAB. The comparison would take place, giving a logical vector. When an "if" or "while" is asked to make a decision about a logical vector or array, it considers it to be true if and only if all of the elements of the vector or array are non-zero (true).

It is well-defined behavior, but if you think about it, the loop would stop as soon as one or more of the elements of N became 0.

You may instead wish to use

while any(N~=[0 0 0])

which could be rewritten

while any(N~=0)

[Jan]

which could be rewritten to "while any(N)".