Thank you for sharing! It's great to have more wavelet libraries. I don't often use those, but when I do the choice is scarce. It's great to have another option!
Can a wavelet be used with SIMD 128bit operations? Or are they used with 4x4 Matrix operators? Are wavelets good for that kind of math?
> Can a wavelet be used with SIMD 128bit operations?<p>Popcount works great in this context, but that only gives you linear speedups. Doing rank/select in O(1) instead of O(N) is a bigger win, and you get that by precomputing superblocks.<p>> Or are they used with 4x4 Matrix operators? Are wavelets good for that kind of math?<p>Nope, different kind of matrix. Just refers to a nicer packing of a wavelet tree with space wasted by bookkeeping pointers between tree nodes.
Does this contain unsafe? Even the Linux kernel's Rust code have memory safety bugs. <a href="https://news.ycombinator.com/item?id=46309536">https://news.ycombinator.com/item?id=46309536</a>
> git clone <a href="https://github.com/math-hiyoko/wavelet-matrix.git" rel="nofollow">https://github.com/math-hiyoko/wavelet-matrix.git</a> && find wavelet-matrix -type f -name '*.rs' -exec grep 'unsafe' {} +<p>No.
No, the library itself does not use unsafe Rust at all.
The Python bindings are built using PyO3, which internally uses unsafe (as required to interface with the CPython C API), but that is fully encapsulated within PyO3. The core data structure and algorithms remain purely safe Rust.
What's a good reference to learn about Wavelet Matrices?
Looks good to me. Have you considered adding a really practical realworld example? As someone who loves looking at examples I like your small examples in the readme, but it still leaves me wondering a bit what I <i>actually</i> would use this library for.<p>Many people don't know what you would use wavelets for or where they really shine. I for example know wavelets are used in image compression algorithms but that's about it. I am curious where else this could be applied.
[flagged]