如何在matlab变量中只存储最多4个小数位？

Question

我希望matlab中的变量能够存储(不要与显示混淆)最多4位小数.是否有内置命令？我尝试了以下 - 但这给出了一个错误:

a = [5.21365458 5.236985475 1.236598547 9.3265874];

k=1;
for i=1:length(a)
ast(k)=sprintf('%5.4f',a(i));
anum(k)=str2num(ast(k));
k=k+1;
end

错误是:??? 下标分配尺寸不匹配.

Answer 1

您应该将数字四舍五入到小数点后四位.这在工作区中很容易做到:

>> x = rand(1,4)
x =
   0.053378064308120   0.051670599653141   0.924623792776560   0.585692341974519
>> x = round(x*1e4) / 1e4
x =
   0.053400000000000   0.051700000000000   0.924600000000000   0.585700000000000

或者你可以写一个roundToDP(x,numberOfDecimalPlaces)为你做的功能:

function x = roundToDP(x,n)
% "Round the matrix x to n decimal places"
x = round(x * 10^n) / 10^n;

现在您可以在工作区中使用该功能:

>> x = rand(1,4)
x =
   0.810201981892601   0.165116049955136   0.457688639337064   0.985975706057179
>> roundToDP(x,4)
ans =
   0.810200000000000   0.165100000000000   0.457700000000000   0.986000000000000