Initial data commit

Task/Percolation-Mean-run-density/Factor/percolation-mean-run-density.factor

@@ -0,0 +1,32 @@
+USING: formatting fry io kernel math math.ranges math.statistics
+random sequences ;
+IN: rosetta-code.mean-run-density
+
+: rising? ( ? ? -- ? ) [ f = ] [ t = ] bi* and ;
+
+: count-run ( n ? ? -- m ? )
+    2dup rising? [ [ 1 + ] 2dip ] when nip ;
+
+: runs ( n p -- n )
+    [ 0 f ] 2dip '[ random-unit _ < count-run ] times drop ;
+
+: rn ( n p -- x ) over [ runs ] dip /f ;
+
+: sim ( n p -- avg )
+    [ 1000 ] 2dip [ rn ] 2curry replicate mean ;
+
+: theory ( p -- x ) 1 over - * ;
+
+: result ( n p -- )
+    [ swap ] [ sim ] [ nip theory ] 2tri 2dup - abs
+    "%.1f  %-5d  %.4f  %.4f  %.4f\n" printf ;
+
+: test ( p -- )
+    { 100 1,000 10,000 } [ swap result ] with each nl ;
+
+: header ( -- )
+    "1000 tests each:\np    n      K       p(1-p)  diff" print ;
+
+: main ( -- ) header .1 .9 .2 <range> [ test ] each ;
+
+MAIN: main