Statistics examples

<!--- PLEASE DO NOT EDIT DIRECTLY. EDIT THE .md.in FILE PLEASE. ---> <div> <span class="quicklinks"> Quick links: &nbsp; <a class="quicklink" href="../reference-main-flag-list/index.html">Flags</a> &nbsp; <a class="quicklink" href="../reference-verbs/index.html">Verbs</a> &nbsp; <a class="quicklink" href="../reference-dsl-builtin-functions/index.html">Functions</a> &nbsp; <a class="quicklink" href="../glossary/index.html">Glossary</a> &nbsp; <a class="quicklink" href="../release-docs/index.html">Release docs</a> </span> </div> # Statistics examples

Computing interquartile ranges

For one or more specified field names, simply compute p25 and p75, then write the IQR as the difference of p75 and p25:

<pre class="pre-highlight-in-pair"> <b>mlr --oxtab stats1 -f x -a p25,p75 \</b> <b> then put '$x_iqr = $x_p75 - $x_p25' \</b> <b> data/medium</b> </pre> <pre class="pre-non-highlight-in-pair"> x_p25 0.24667037823231752 x_p75 0.7481860062358446 x_iqr 0.5015156280035271 </pre>

For wildcarded field names, first compute p25 and p75, then loop over field names with p25 in them:

<pre class="pre-highlight-in-pair"> <b>mlr --oxtab stats1 --fr '[i-z]' -a p25,p75 \</b> <b> then put 'for (k,v in $*) {</b> <b> if (k =~ "(.*)_p25") {</b> <b> $["\1_iqr"] = $["\1_p75"] - $["\1_p25"]</b> <b> }</b> <b> }' \</b> <b> data/medium</b> </pre> <pre class="pre-non-highlight-in-pair"> i_p25 2501 i_p75 7501 x_p25 0.24667037823231752 x_p75 0.7481860062358446 y_p25 0.25213670524015686 y_p75 0.7640028449996572 i_iqr 5000 x_iqr 0.5015156280035271 y_iqr 0.5118661397595003 </pre>

Computing weighted means

This might be more elegantly implemented as an option within the stats1 verb. Meanwhile, it's expressible within the DSL:

<pre class="pre-highlight-in-pair"> <b>mlr --from data/medium put -q '</b> <b> # Using the y field for weighting in this example</b> <b> weight = $y;</b> <b></b> <b> # Using the a field for weighted aggregation in this example</b> <b> @sumwx[$a] += weight * $i;</b> <b> @sumw[$a] += weight;</b> <b></b> <b> @sumx[$a] += $i;</b> <b> @sumn[$a] += 1;</b> <b></b> <b> end {</b> <b> map wmean = {};</b> <b> map mean = {};</b> <b> for (a in @sumwx) {</b> <b> wmean[a] = @sumwx[a] / @sumw[a]</b> <b> }</b> <b> for (a in @sumx) {</b> <b> mean[a] = @sumx[a] / @sumn[a]</b> <b> }</b> <b> #emit wmean, "a";</b> <b> #emit mean, "a";</b> <b> emit (wmean, mean), "a";</b> <b> }'</b> </pre> <pre class="pre-non-highlight-in-pair"> a=pan,wmean=4979.563722208067,mean=5028.259010091302 a=eks,wmean=4890.3815931472145,mean=4956.2900763358775 a=wye,wmean=4946.987746229947,mean=4920.001017293998 a=zee,wmean=5164.719684856538,mean=5123.092330239375 a=hat,wmean=4925.533162478552,mean=4967.743946419371 </pre>