using strictmath::cbrt

Author: loyispa

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "sketches-rust"
-version = "0.2.1"
+version = "0.2.2"
 authors = ["loyispa <litiegen456250@gmail.com>"]
 license = "Apache-2.0"
 edition = "2021"
@@ -10,4 +10,5 @@ homepage = "https://github.com/loyispa/sketches-rust"
 description = "Rust implementation of DDSketch."
 exclude = [".gitignore"]
 
-[dependencies]
+[dependencies]
+rust-strictmath = "0.1.1"

src/index_mapping/mod.rs

@@ -1,5 +1,6 @@
 use crate::sketch::{Flag, FlagType};
 use crate::{serde, Error};
+use rust_strictmath::cbrt;
 
 use crate::output::Output;
 
@@ -159,7 +160,7 @@ impl IndexMapping {
                         * CUBICALLY_INTERPOLATED_MAPPING_A
                         * CUBICALLY_INTERPOLATED_MAPPING_A
                         * (index - index.floor());
-                let p: f64 = ((d1 - (d1 * d1 - 4.0 * d0 * d0 * d0).sqrt()) / 2.0).cbrt();
+                let p: f64 = cbrt((d1 - (d1 * d1 - 4.0 * d0 * d0 * d0).sqrt()) / 2.0);
                 let significand_plus_one: f64 = -(CUBICALLY_INTERPOLATED_MAPPING_B + p + d0 / p)
                     / (3.0 * CUBICALLY_INTERPOLATED_MAPPING_A)
                     + 1.0;