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Re: how to make a matrix with all combinations of digits efficiently
From: |
Juan Pablo Carbajal |
Subject: |
Re: how to make a matrix with all combinations of digits efficiently |
Date: |
Fri, 29 Dec 2017 19:13:47 +0100 |
> in fact I need decomp(10,10)
The issue with memory or index size are rather unavoidable. Do you
really need all this?
What is your intended use of counter? I am pretty sure you do not neet
to allocate nor have simultaneously such an enormous amount of
numbers.
Note that my solution works even for a single number "i", that means
you could call the function to decompose a given number everytime you
need a results, i.e.
function digits = dec2digit (num, base = 10)
nc = ceil (log (num) / log (base));
digits = mod( floor (num ./ base.^[(nc-1):-1:0]), base);
endfunction
example
dec2digit (537)
ans =
5 3 7
another one
d = dec2digit (707, 16);
n = length (d);
d * 16.^[(n-1):-1:0].'
ans = 707
another one
num = randi (10e10);
dec2digit (num) # this one should be one of the ones you need.
If you are calling this from a loop, then you do not have memory
problems. You cna also use batches of numbers that follow a memory
restriction, i.e. work with batches of 1MB, then 1e6/8/10 is more or
less the number of rows of the matrix for that batch.
- how to make a matrix with all combinations of digits efficiently, Jean Dubois, 2017/12/28
- Re: how to make a matrix with all combinations of digits efficiently, Juan Pablo Carbajal, 2017/12/28
- Re: how to make a matrix with all combinations of digits efficiently, Jean Dubois, 2017/12/29
- Re: how to make a matrix with all combinations of digits efficiently, Francesco PotortÃ¬, 2017/12/29
- Re: how to make a matrix with all combinations of digits efficiently, Jean Dubois, 2017/12/29
- Re: how to make a matrix with all combinations of digits efficiently, Francesco PotortÃ¬, 2017/12/29
- Re: how to make a matrix with all combinations of digits efficiently,
Juan Pablo Carbajal <=
- Re: how to make a matrix with all combinations of digits efficiently, Jean Dubois, 2017/12/30
- Re: how to make a matrix with all combinations of digits efficiently, Jean Dubois, 2017/12/30
- Re: how to make a matrix with all combinations of digits efficiently, Juan Pablo Carbajal, 2017/12/30
- Re: how to make a matrix with all combinations of digits efficiently, Juan Pablo Carbajal, 2017/12/30