Grasshopper

algorithmic modeling for Rhino

# Permutations vs Combinations

These two algorithms is a trial to create a system for permutations and combinations

it depends on a mathematical operation called factorial

I wish if David can add the operation to the expression editor

N! = 5! = 5 * 4 * 3 * 2 * 1

credit to this video series

It helps find how many variations you can generate per group from a pool of selectable items.

I had my own version also

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According to references

Permutation means arranging members of a set(a,b,c etc) into sequences (i.e. 3 keys each time), that means the order is important(ABC *= CBA).

But Combination means selection of unique possible sets in sequences(ABC = CBA), with order ignored.

this why it was possible to extract combinations from permutations without iterations, by only eliminating similar characters with matching characters.

That brings the question, whether it's possible to generate the combinations (56) without generating the whole possible (336) permutations, which already took around 8000 iterations

Update:

This option is super fast (unbelievably fast) just like Python speed, using Anemone (Fast Loop)

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by June Lee

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