Math::NumSeq::DigitCount -- count of a given digit
use Math::NumSeq::DigitCount; my $seq = Math::NumSeq::DigitCount->new (radix => 10, digit => 9); my ($i, $value) = $seq->next;
The count of how many of a given digit is in $i when written out in a given radix. The default is to count how many 9s in decimal.
$i
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, ... starting i=0
For example i=19 has a single "9" so value=1.
The radix and digit options can select a different number base or different digit to count. For example to count the 0-bits in binary,
radix
digit
# radix=>2, digit=>0 0, 0, 1, 0, 2, 1, 1, 0, 3, 2, 2, 1, 2, 1, 1, 0, 4, 3, 3, 2, ... starting i=0
i=0 is treated as no digits at all, so it has value=0 for the count of 0-bits, and similarly in other bases counting 0 digits.
Option digit => -1 gives the highest digit in the radix, ie. radix-1. This is the default, so if radix is given the count is of its biggest digit.
digit => -1
See "FUNCTIONS" in Math::NumSeq for behaviour common to all sequence classes.
$seq = Math::NumSeq::DigitCount->new (radix => $r, digit => $d)
Create and return a new sequence object.
digit can be -1 to mean digit radix-1, the highest digit in the radix.
$value = $seq->ith($i)
Return how many of the given digit is in $i written in radix.
$bool = $seq->pred($value)
Return true if $value might occur as a digit count, which means simply $value>=0.
$value
$value>=0
Math::NumSeq, Math::NumSeq::DigitLength, Math::NumSeq::RadixWithoutDigit
http://user42.tuxfamily.org/math-numseq/index.html
Copyright 2010, 2011, 2012, 2013, 2014, 2016, 2017, 2019, 2020 Kevin Ryde
Math-NumSeq is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.
Math-NumSeq is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with Math-NumSeq. If not, see <http://www.gnu.org/licenses/>.
To install Math::NumSeq, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Math::NumSeq
CPAN shell
perl -MCPAN -e shell install Math::NumSeq
For more information on module installation, please visit the detailed CPAN module installation guide.