Consider fixing Ruby warnings

[bhb]

Thanks for the great gem!

When I use distribution 0.8.0 in my project, I have warnings enabled (to catch problems with own code). However, the distribution gem itself emits various "assigned but unused variable", "possibly useless use of * in void context" and "method redefined" warnings.

These warnings might indicate actual bugs, but more likely, they are just code cleanup items.

Repro:

ruby -w -e 'require "distribution"'

Result

/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/math_extension/incomplete_gamma.rb:206: warning: assigned but unused variable - ln_term_err
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/math_extension/incomplete_gamma.rb:289: warning: possibly useless use of * in void context
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/math_extension/incomplete_gamma.rb:289: warning: possibly useless use of * in void context
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/math_extension/incomplete_gamma.rb:404: warning: assigned but unused variable - g_da_err
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/math_extension/incomplete_beta.rb:11: warning: assigned but unused variable - sign
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/math_extension/incomplete_beta.rb:27: warning: assigned but unused variable - gsy_err
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old norm_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of norm_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old norm_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of norm_pdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old chisq_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of chisq_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old chisq_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of chisq_pdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old gamma_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of gamma_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old gamma_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of gamma_pdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old beta_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of beta_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old beta_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of beta_pdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old tdist_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of tdist_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old tdist_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of tdist_pdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old fdist_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of fdist_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old fdist_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of fdist_pdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old bnor_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of bnor_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old bnor_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of bnor_pdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old bino_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of bino_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old bino_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of bino_pdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old hypg_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of hypg_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old hypg_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of hypg_pdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old expo_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of expo_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old expo_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of expo_pdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old pois_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of pois_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old pois_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of pois_pdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old logis_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of logis_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old logis_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of logis_pdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old lognormal_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of lognormal_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old lognormal_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of lognormal_pdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old weibull_cdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of weibull_cdf was here
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/shorthand.rb:12: warning: method redefined; discarding old weibull_pdf
/Users/benbrinckerhoff/.rbenv/versions/3.2.2/lib/ruby/gems/3.2.0/gems/distribution-0.8.0/lib/distribution/distributable.rb:26: warning: previous definition of weibull_pdf was here