Why does str2num truncate my number so early?

2014 6 23
2 个回答
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更新时间：2022 2 7
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0 个投票

When I try to convert from string to number, I lose precision?
whos test_str
Name Size Bytes Class Attributes
test_str 1x9 18 char
K>> test_str
test_str =
0.067354
K>> str2num(test_str)
ans =
0.0674

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 采纳的回答

José-Luis
José-Luis 2014-6-23

1 个投票

format long
str2num(test_str)

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Andrew Reibold
Andrew Reibold 2014-6-23
Thank you Jose-Luis
This worked great. I presume that this changes the format for any future things I type as well?
Does anyone know what is the 'default' format if it is not long?
José-Luis
José-Luis 2014-6-23
You could read the documentation:
doc format
Note that this only changes how the number is displayed. Its internal representation is, by default in Matlab, a double.

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Sara
Sara 2014-6-23

0 个投票

Use
sprintf
so you can control the precision you want.

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Andrew Reibold
Andrew Reibold 2014-6-23
编辑：Andrew Reibold 2014-6-23
Doesn't this return a string?
I am trying to convert a string to a number/double/float.
Sara
Sara 2014-6-23
I read it the other way around, sorry.
Yep but that method is not efficient. There should be a way to use the exact number of decimals. What if I am using srt2num to find a folder with the same number I looked for?

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