doc: begin experiments section

doc/.latexmkrc

@@ -0,0 +1,29 @@
+@default_files = ('report.Rnw');
+$latex = 'latex  %O  --shell-escape %S';
+$pdflatex = 'pdflatex --shell-escape %S -synctex=1 %O %S';
+$pdf_mode = 1;
+$clean_ext = 'lol nav snm loa bbl* glo ist tex aux bbl blg log out toc Rnw.tex %R-concordance.tex %R.tex';
+$bibtex_use = 2;
+
+# only enable when compiling .Rnw or .Rtex file
+if(grep(/\.(rnw|rtex)$/i, @ARGV)) {
+    $latex = 'internal knitrlatex ' . $latex;
+    $pdflatex = 'internal knitrlatex ' . $pdflatex;
+    my $knitr_compiled = {};
+    sub knitrlatex {
+        for (@_) {
+            next unless -e $_;
+            my $input = $_;
+            next unless $_ =~ s/\.(rnw|rtex)$/.tex/i;
+            my $tex = $_;
+            my $checksum = (fdb_get($input))[-1];
+            if (!$knitr_compiled{$input} || $knitr_compiled{$input} ne $checksum) {
+                my $ret = system("Rscript -e \"knitr::knit('$input')\"");
+                if($ret) { return $ret; }
+                rdb_ensure_file($rule, $tex);
+                $knitr_compiled{$input} = $checksum;
+            }
+        }
+        return system(@_);
+    }
+}