small floating point has been considred as zero value!

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juvanni
juvanni 2024-3-1
回答： Steven Lord 2024-3-1
hi,
x=0.16
if x>0.1
d=1
else
d=0
end
the answer is 0
I do not know where is the problem?
  1 个评论
Les Beckham
Les Beckham 2024-3-1
Ran in:
I don't see a problem. Are you sure this is really the code that you are having the problem with?
x = 0.16
x = 0.1600
if x > 0.1
d = 1
else
d = 0
end
d = 1

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回答（2 个）

Steven Lord
Steven Lord 2024-3-1
Ran in:
More likely than not, your value for x is not what you think it is. If we run your code on Answers:
x=0.16
x = 0.1600
if x>0.1
d=1
else
d=0
end
d = 1
Now if your number was part of a larger array with numbers of varying magnitudes, part of the display may look like 0.16 without it actually being 0.16:
x = [1e-6 0.16e-3]
x = 1x2
1.0e-03 * 0.0010 0.1600
Note that x(2) displays as 0.16 but there's that "1.0e-03 *" right below the name of the variable. So it's actually much smaller; basically one one-thousandth of 0.16:
y = x(2)
y = 1.6000e-04
1000*y-0.16
ans = 0
and that is not greater than 0.1 (aka 1.0000e-01)
format shorte
z = 0.1
z =
1.0000e-01
So when we use y in place of 0.16, MATLAB correctly identifies that y is not greater than 0.1:
if y > 0.1
d = 1
else
d = 0
end
d =
0
Star Strider
Star Strider 2024-3-1
Ran in:
Your code works correctly when I run it here —
x=0.16
x = 0.1600
if x>0.1
d=1
else
d=0
end
d = 1
d
d = 1
.

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