Champernowne Constant loop help

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Nguyen Huy 2021-5-15

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https://ww2.mathworks.cn/matlabcentral/answers/830973-champernowne-constant-loop-help

编辑： Jonas 2021-5-16

%i have Champernowne Constant is a real number whose digits in decimal representation come from the concatenation of all consecutive positive integers starting from 1. ex:'12345678910111213....'

%my job is return array vy contain nth digit from Champernowne Constant,n is take from array vx

%ex: vx=[10 11 12 13 14 15] => vy=[ 1 0 1 1 1 2]

%my code is

vy=[]

for i=1:length(vx)

str='';

j=1;

while length(str)<vx(i)

str=strcat(str,num2str(j));

j=j+1;

end

vy=[vy str2num(str(vx(i)))];

end

%the code is success with litte vx,but with lagre vx it over max loop of matlab,so how could i fix

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Jonas 2021-5-16

编辑：Jonas 2021-5-16

在 MATLAB Online 中打开

maybe it helps if you have a look into the width of numbers: the numbers from 0:9 have size ceil(log10(number))=1, after that the numbers from 10:99 have width ceil(log10(numbers))=2 and so on. this way you could have a look only on the numbers in the decade you are interested in.

by the way, how big gets your n? you can easily use smth like

sprintf('%i',1:10000)

and then extract the numbers you are interested in?

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