Merge pull request #65 from ava57r/main-utils

add module utils

src/lib.rs

@@ -93,6 +93,7 @@ pub mod index;
 pub mod metric;
 pub mod selector;
 pub mod vector_transform;
+pub mod utils;
 
 #[cfg(feature = "gpu")]
 pub mod gpu;

src/utils.rs

@@ -0,0 +1,23 @@
+/// L2-renormalize a set of vector. Nothing done if the vector is 0-normed
+pub fn fvec_renorm_l2(d: usize, nx: usize, fvec: &mut [f32]) {
+    unsafe { faiss_sys::faiss_fvec_renorm_L2(d, nx, fvec.as_mut_ptr()) }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use super::*;
+
+    const D: u32 = 8;
+
+    #[test]
+    fn check_fvec_renorm_l2_01() {
+        let mut some_data = vec![
+            7.5_f32, -7.5, 7.5, -7.5, 7.5, 7.5, 7.5, 7.5, -1., 1., 1., 1., 1., 1., 1., -1., 0., 0.,
+            0., 1., 1., 0., 0., -1., 100., 100., 100., 100., -100., 100., 100., 100., 120., 100.,
+            100., 105., -100., 100., 100., 105.,
+        ];
+
+        fvec_renorm_l2(D as usize, 5, &mut some_data);
+    }
+}