No POD found for histogram_agg.c. Time to read the source?
histogram_agg.c
To install Math::SimpleHisto::XS, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Math::SimpleHisto::XS
CPAN shell
perl -MCPAN -e shell install Math::SimpleHisto::XS
For more information on module installation, please visit the detailed CPAN module installation guide.