Why Combinatorics package doesn't warn of overflow?

This is dangerous, as the following code doesn’t emit any warning, just give very different results (I assume due to overflowing ???)

using Combinatorics

# 4 players get exactly one ace each:
sol1 = 4 * 3 *2 * multinomial(12,12,12,12)/multinomial(13,13,13,13) # 0 .838
sol2 = 4 * 3 *2 * (multinomial(12,12,12,12)/multinomial(13,13,13,13)) # -9.47
sol3 = 4 * 3 *2 * (multinomial(BigInt(12),12,12,12)/multinomial(BigInt(13),13,13,13)) # 0.105
sol4 = 4 * 3 *2 * multinomial(BigInt(12),12,12,12)/multinomial(BigInt(13),13,13,13) # 0.105
sol5 = 4 * 3 *2 * (multinomial(BigInt(12),BigInt(12),BigInt(12),BigInt(12))/multinomial(BigInt(13),BigInt(13),BigInt(13),BigInt(13))) # 0.105

yep, not making it “big” by default, you can file an issue maybe

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yep… interesting, I thought the overflow error was a “safety net” of the language, while it is instead a check specifically implemented in the binomial function… so, if the individual binomial computation in multinomial doesn’t overflow, neither does multinomial, e.g.

multinomial(150, 150, 150, 150) --> error overflow
multinomial(15, 15, 15, 15) --> no error reported

right; Julia by default does not check overflow, for performance reason, similar to C/C++. But pkgs like Combinatorics I’d imagine have good reason to either make big by default(see for example derangement function), or check overflow.

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