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Yuri Astrakhan nyurik

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nyurik / link.md
Last active October 25, 2023 14:07
SCSC2023
@nyurik
nyurik / gist:101bee2358c2e08bbe8503c120cbaca2
Created June 10, 2023 18:13
MapLibre https://docs.google.com/presentation/d/1iQFFMCuIPLYdUiEgeFsO8fKTQB6ArSM8GrxLKXxY-RQ/edit?usp=sharing
https://docs.google.com/presentation/d/1iQFFMCuIPLYdUiEgeFsO8fKTQB6ArSM8GrxLKXxY-RQ/edit?usp=sharing
@nyurik
nyurik / gist:3f44ad42b062da14243df8159e058b1b
Last active June 9, 2023 16:14
The future of MVT presentation https://docs.google.com/presentation/d/1Rl3k_bu7e3YZ-p8mGoQ-rqeJIUUlr6JfDSTCg3cWAog
https://docs.google.com/presentation/d/1Rl3k_bu7e3YZ-p8mGoQ-rqeJIUUlr6JfDSTCg3cWAog
@nyurik
nyurik / format.rs
Last active June 1, 2023 01:21
Rust format! double referencing performance impact
// Place this page as /benches/format.rs in a rust project created with `cargo new fmttest --lib`
// Add to Cargo.toml:
//
// [dev-dependencies]
// criterion = { version = "0.4", features = ["html_reports"] }
//
// [[bench]]
// name = "format"
// harness = false
@nyurik
nyurik / benches_iters.rs
Last active May 9, 2023 02:37
Add “iterate with separators” iterator function
// Benchmarks for the Rust iterator extension discussion at
// https://internals.rust-lang.org/t/add-iterate-with-separators-iterator-function/18781/13
// Place this page as /benches/iters.rs in a rust project created with `cargo new itertest --lib`
// Add to Cargo.toml:
//
// [dependencies]
// itertools = "0.10"
//
@nyurik
nyurik / bench.rs
Created April 5, 2023 19:30
Benchmark to evaluate linear vs dup-indexer performance
use criterion::{black_box, criterion_group, criterion_main, Criterion};
use dup_indexer::DupIndexer;
fn benchmark_strings(c: &mut Criterion) {
let mut group = c.benchmark_group("Strings");
group.bench_function("String", |b| {
b.iter(|| {
let mut di = DupIndexer::new();
for _ in 0..100 {
@nyurik
nyurik / query.sql
Created January 16, 2023 05:58
Statistics of MVT tile GIS errors when encoding/decoding with ST_AsMVTGeom
SELECT x,
y,
ST_Y(p_mid) mid_lat,
ST_Y(p_min) min_lat,
ST_Y(p_max) max_lat,
ST_Y(d_mid) mid_lat_decoded,
ST_Y(d_min) min_lat_decoded,
ST_Y(d_max) max_lat_decoded,
abs(ST_Y(p_mid) - ST_Y(d_mid)) mid_lat_error,
abs(ST_Y(p_min) - ST_Y(d_min)) min_lat_error,
@nyurik
nyurik / optimized-mbtiles.sql
Created June 10, 2022 19:25
Some ideas on optimizing mbtiles file storage size with a single 32-bit index instead of z/x/y
create table map
(
tile_index INTEGER,
tmp_zoom INTEGER GENERATED ALWAYS AS ((tile_index & 0xFC000000) >> 26) VIRTUAL,
tile_column INTEGER GENERATED ALWAYS AS (CASE
WHEN tmp_zoom <= 13 THEN (tile_index & 0x3FFE000) >> 13
ELSE (tile_index & 0x3FFF8000) >> 15 END) VIRTUAL,
tile_row INTEGER GENERATED ALWAYS AS (CASE
WHEN tmp_zoom <= 13 THEN tile_index & 0x1FFF
ELSE tile_index & 0x7FFF END) VIRTUAL,
@nyurik
nyurik / types.rs
Last active February 21, 2022 22:56
Multidimensional Geo-types with separate Metadata
use num_traits::{Float, Num, NumCast};
use std::fmt::Debug;
trait CoordinateType: Default + Num + Copy + NumCast + PartialOrd + Debug {}
impl<T: Default + Num + Copy + NumCast + PartialOrd + Debug> CoordinateType for T {}
trait CoordNum: CoordinateType {}
impl<T: CoordinateType + Debug> CoordNum for T {}
trait CoordFloat: CoordNum + Float {}
@nyurik
nyurik / types.rs
Last active February 21, 2022 16:21
Multidimensional Geo-types
use num_traits::{Float, Num, NumCast};
use std::fmt::Debug;
trait CoordinateType: Default + Num + Copy + NumCast + PartialOrd + Debug {}
impl<T: Default + Num + Copy + NumCast + PartialOrd + Debug> CoordinateType for T {}
trait CoordNum: CoordinateType {}
impl<T: CoordinateType + Debug> CoordNum for T {}
trait CoordFloat: CoordNum + Float {}