MATLAB Answers

Zaza
0

how can i compute the length of an integer?

Asked by Zaza
on 4 Jan 2013
if i have
int = 12345;
length_int = 5;
???

  1 Comment

Jan
on 4 Jan 2013
What is the "length" of -1 and 0?

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3 Answers

Answer by Azzi Abdelmalek
on 4 Jan 2013
Edited by Azzi Abdelmalek
on 4 Jan 2013
 Accepted Answer

int=-123456789
max(ceil(log10(abs(int))),1)

  0 Comments

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Answer by Sean de Wolski
on 4 Jan 2013
Edited by Sean de Wolski
on 4 Jan 2013

Edit
nnz(num2str(int) - '-')

  4 Comments

Show 1 older comment
Friedrich, neither work actually, consider -12345.
Good point Sean. But then
numel(num2str(abs(int)))
should do ;)
arghh, you win!

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Answer by Davide Ferraro on 4 Jan 2013

Casting the variable into a string may be risky because you may get to "unexpected" cases such as:
int = 12345678901234567890123
numel(num2str(int))
ans =
12
You may consider a numeric approach using LOG10: floor(log10(int))+1 all numbers between 10 and 100 will have a LOG10 between 1 and 2 so you can use FLOOR to get the lower value (1 in this case) and then you need to add the value 1 cause you are trying to compute the number of digits and not the power of ten.

  1 Comment

G A
on 4 Jan 2013
why, it works:
>> int = 12345678901234567890123
numel(num2str(int))
int =
1.2346e+22
ans =
23

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