Add rustlib package

rustlib/src/lib.rs

@@ -0,0 +1,26 @@
+use js_sys::Array;
+use serde_wasm_bindgen::from_value;
+use fanova::{FanovaOptions, RandomForestOptions};
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen]
+pub fn wasm_fanova_calculate(features: Array, targets: Array) -> Vec<f64> {
+    // TODO(c-bata): Fix error handling
+    let features_vec: Vec<Vec<f64>> = features
+        .iter()
+        .map(|x| from_value::<Vec<f64>>(x).unwrap())
+        .collect();
+    let targets_vec: Vec<f64> = targets.iter().map(|x| x.as_f64().unwrap()).collect();
+
+    let mut fanova = FanovaOptions::new()
+        .random_forest(RandomForestOptions::new().seed(0))
+        .fit(
+            features_vec.iter().map(|x| x.as_slice()).collect(),
+            &targets_vec,
+        )
+        .unwrap();
+    let importances = (0..features_vec.len())
+        .map(|i| fanova.quantify_importance(&[i]).mean)
+        .collect::<Vec<_>>();
+    return importances;
+}