if else loop

I have a variable "v" in my code which after calculation gets value either 1 or 1.0000 And 1 is not equal to 1.0000 here. I want to apply a if else if loop as follows : if v==1 statements elseif v==1.0000 statements else statements end

But this is not working. Please tell me the correct way to do it. Matlab isn't executing "v==1.0000". Why??

[Walter Roberson]

There is no such thing as an "if loop". "if" does not loop: it executes once. "if" might be coded within a loop, but it is not a loop.

Answer 1

[Daniel Shub]

Try

format long

and then look at your v. You can also look at

v-1

What you will see is that when MATLAB says v is equal to 1.0000, what MATLAB is telling you is that v is not equal to 1, but rather something slight more than 1.

There is a huge discussion here (and else where) on floating point comparisons.

Answer 2

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#Why_is_0.3_-_0.2_-_0.1_.28or_similar.29_not_equal_to_zero.3F