I need to implement the log gamma function just as numpy does: https://github.com/numpy/numpy/blob/158159d43a988ff418df5aee3c8b3ecfcb1d0986/numpy/random/src/legacy/legacy-distributions.c#L292 but for big integers/big decimals, just like Java's BigInteger/BigDecimal.
What would be the best rust crate for such thing? I found https://github.com/rust-num/num but this looks like it's just for traits.
I also found https://github.com/akubera/bigdecimal-rs which does BigDecimal but then I cannot convert to BigInteger when needed because this only supports BigDecimal
1 Like
H2CO3
August 23, 2021, 1:39pm
2
A BigDecimal can trivially represent a big integer. But there's also the num_bigint crate which only works with integers.
yes, but what should I use for BigDecimal?
H2CO3
August 23, 2021, 2:01pm
4
You linked to the bigdecimal crate yourself; that should be fine.
even if performance is critical?
I don't see other options. Do you know something better to do very fast math on Rust for big decimals?
ZiCog
August 23, 2021, 8:33pm
6
What gmp-mpfr-sys about https://crates.io/crates/gmp-mpfr-sys ?
Presumably performance is assured as it is a binding the the very fast GNU arbitrary-precision libraries.
1 Like
system
November 21, 2021, 8:33pm
7
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