Perl | log() Function
log() function in Perl returns the natural logarithm of value passed to it. Returns $_ if called without passing a value. log() function can be used to find the log of any base by using the formula:
Syntax: log(value)
Parameter:
value: Number of which log is to be calculatedReturns:
Floating point number in scalar context
Example 1:
#!/usr/bin/perl -w # Calculating log of base 10 # using log function print "log10(2): " , log10(2), "\n" ; print "log10(7): " , log10(7), "\n" ; print "log10(9): " , log10(9), "\n" ; # Function for log10 calculator sub log10 { my $n = shift ; # using pre-defined log function return log ( $n ) / log (10); } |
Output:
log10(2): 0.301029995663981 log10(7): 0.845098040014257 log10(9): 0.954242509439325
Example 2:
#!/usr/bin/perl -w # Calculating log of different # base using log function print "log3(2): " , log3(2), "\n" ; print "log5(7): " , log5(7), "\n" ; print "log2(9): " , log2(9), "\n" ; # Function for log3 calculator sub log3 { my $n = shift ; # using pre-defined log function return log ( $n ) / log (3); } # Function for log5 calculator sub log5 { my $n = shift ; # using pre-defined log function return log ( $n ) / log (5); } # Function for log2 calculator sub log2 { my $n = shift ; # using pre-defined log function return log ( $n ) / log (2); } |
Output:
log3(2): 0.630929753571457 log5(7): 1.20906195512217 log2(9): 3.16992500144231