四舍五入为有效数字 [英] Rounding to n significant digits

问题描述

我试图在MATLAB中编写代码，将数字整数（如我要求的）有效数字。

我不知道该怎么做。有什么建议？

解决方案

转到 d 有效数字：

 >> d = 3; ％//位数
>> x = 5.237234; ％//示例编号
 
>> D = 10 ^（d-ceil（log10（x）））; 
>> y = round（x * D）/ D 
y = 
 5.2400 
  

$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $' >> d = 3; ％//位数
>> x = 5.237234; ％//示例编号

>> D = 10 ^ d;
>> y = round（x * D）/ D
y =
5.2370

编辑

其实它更简单：

 >> d = 3; 
>> x = 5.237234; 
>> y = round（x，d，'significant'）
 y = 
 5.2400 
 
>> d = 3; 
>> x = 5.237234; 
>> y = round（x，d）％//或y = round（x，d，'decimals'）
y = 
 5.2370 
  

I'm trying to write code in MATLAB that will round number to certain (as I ask) significant digits.

I'm not sure how to do it. Any suggestions?

解决方案

To round to d significant digits:

>> d = 3; %// number of digits
>> x = 5.237234; %// example number

>> D = 10^(d-ceil(log10(x)));
>> y = round(x*D)/D
y =
    5.2400

To round to d decimal digits:

>> d = 3; %// number of digits
>> x = 5.237234; %// example number

>> D = 10^d;
>> y = round(x*D)/D
y =
    5.2370

EDIT

Actually it's easier: the round function supports these options:

>> d = 3;
>> x = 5.237234;
>> y = round(x, d, 'significant')
y =
    5.2400

>> d = 3;
>> x = 5.237234;
>> y = round(x, d) %// or y = round(x, d, 'decimals')
y =
    5.2370

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