how to let my code just consider the demical number ??

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Muhammad RSMY 2017-12-27

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评论： Muhammad RSMY 2017-12-27

采纳的回答： David Goodmanson

Dear friends

sorry for bothering you guy, can anyone help how to code, asking matlab to only consider the decimal

for example 45.789

I just be coding need to detect the numbers after (.), in another words I need to detect only 789

maybe my question is so silly but sorry due to lack of my knowledge

Thanks a lot guys

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Walter Roberson 2017-12-27

Is the input a string? Because if it is floating point then there are multiple valid answers. Remember that floating point numbers are not stored in decimal and that 1/10 cannot be exactly represented in floating point, much the same way that 1/3 cannot be exactly represented in finite decimal

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Answer 1

David Goodmanson 2017-12-27

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https://ww2.mathworks.cn/matlabcentral/answers/374606-how-to-let-my-code-just-consider-the-demical-number#answer_297772

编辑：David Goodmanson 2017-12-27

在 MATLAB Online 中打开

Hi Muhammad,

You need the integer part, and the fix function works:

a = 45.789
>> fix(a)
ans =  45
>> b = a-fix(a)
b = 0.7890

For positive a, the floor function gives the same result as fix. However, fix works for both positive and negative a (giving -.789 in the latter case). Floor works as intended only for positive a. See help floor, help fix for the difference in the two functions.

Another way, which also works for both signs, is

b = rem(a,1)

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Image Analyst 2017-12-27

What does that mean? There are many, many digits to the right of the decimal place. What does "consider" mean to you? Do you want to multiply by 1000 and cast to integer so you get only 3 decimal places? If not, then what you do mean exactly?

Muhammad RSMY 2017-12-27