Get logarithm of base 10

tamaguchi has asked for the wisdom of the Perl Monks concerning the following question:

Hello all As I know it natural logarithm of a number "$number" is written in perl as: log($numer) but how is it possible to get the logarithm with base 10 or other logartms such as with base 2 etc. Thank you for any help.

2006-02-28 Retitled by jdporter, as per Monastery guidelines
Original title: 'Logarithms'

Comment on Get logarithm of base 10

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Re: Get logarithm of base 10 by dempa (Friar) on Feb 28, 2006 at 12:51 UTC
From "perldoc -f log": To get the log of another base, use basic algebra: The base-N log of a number is equal to the natural log of that number divided by the natural log of N. For example: `sub log10 { my $n = shift; return log($n)/log(10); }` [download] -- dempa	[reply] [d/l]
Re: Get logarithm of base 10 by northwind (Hermit) on Feb 28, 2006 at 13:00 UTC
Or if you wanted base N (where N could be 2, π, 10, 16, etc.)... `sub log_N { my $num = shift; my $base = shift; return log($num)/log($base); }` [download]	[reply] [d/l]
Re: Get logarithm to base 10 by ChemBoy (Priest) on Feb 28, 2006 at 19:25 UTC
As an alternative to the techniques already mentioned, you could always `use POSIX 'log10';` (assuming that's not too easy ;-). If God had meant us to fly, he would never have given us the railroads. --Michael Flanders	[reply] [d/l]