What does a = b+c ~= d/e mean?
显示 更早的评论
Hi!
I have a situation in my code like this:
a = b+c ~= d/e;
where a, b, c, d and e are real numbers, but I don't know what this expression means...
Can you help me, please?
Thank you! :D
采纳的回答
Voss
2023-3-4
a = b+c ~= d/e;
for scalars b, c, d, and e, is the same as
if b+c ~= d/e
a = true;
else
a = false;
end
6 个评论
Walter Roberson
2023-3-4
Note that ~= has a low priority, so the code is interpreted as
(b+c) ~= (d/e)
Laura Costa Pereira Miranda
2023-3-6
Yes, a will be either true or false. a will be a logical scalar.
When you display a, true is represented as a 1 and false is represented as a 0:
a = true
a = false
But notice they are of class logical, not double (or some other numeric class).
However, if you use a in a calculation, the value 0 or 1 will be used:
a = true;
result = a+4 % true+4 is interpreted as 1+4
a = false;
result = false*8 % false*8 is interpreted as 0*8
and result is of class double (the default numeric class):
class(result)
Laura Costa Pereira Miranda
2023-3-6
Voss
2023-3-6
You're welcome!
By the way, in the context of if or while then an expression is considered true if the expression evaluates to something that is all non-zero (if it evaluates to contain nan then you will get an error)
if -3:2:5; disp('yep okay'); else disp('nope'); end
if -4:2:4; disp('yep okay'); else disp('nope'); end
The first one is completely non-zero but the second one contains at least one zero.
更多回答（0 个）
类别
在 帮助中心 和 File Exchange 中查找有关 Logical 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
