OSCAT Forum
oscat.lib => oscat.lib fuer TwinCAT/CoDeSys => Thema gestartet von: vladimirsitnikov am 22. Juli 2016, 12:04:27
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Here's what _ARRAY_SHUFFLE uses:
stop := UINT_TO_INT(SHR(size,2)-1);
FOR i := 0 TO stop DO
pos := RDM2(i+pos,0,stop);
(* swap elements *)
temp := pt^[i];
pt^[i] := pt^[pos];
pt^[pos] := temp;
END_FOR;
Technically speaking, for Fisher–Yates shuffle (see https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle) a loop of length "size" is required, not "size/2-1".
Does it make sense to correct the shuffle so it implemets Fisher-Yates properly?