From 517c58bfef1a6e6511025c458ad0ba6b37ec066a Mon Sep 17 00:00:00 2001
From: Palash Tyagi <23239946+Magnus167@users.noreply.github.com>
Date: Thu, 17 Apr 2025 11:58:53 +0100
Subject: [PATCH] add unit tests for Matrix<T> and f64-specific helpers

---
 tests/mat_tests.rs | 124 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 124 insertions(+)
 create mode 100644 tests/mat_tests.rs

diff --git a/tests/mat_tests.rs b/tests/mat_tests.rs
new file mode 100644
index 0000000..7ac9c6b
--- /dev/null
+++ b/tests/mat_tests.rs
@@ -0,0 +1,124 @@
+// Unit tests for Matrix<T> and its f64‑specific helpers.
+
+#[cfg(test)]
+mod tests {
+    use rustframe::frame::mat::{Axis, Matrix};
+    use std::f64::NAN;
+
+    const EPS: f64 = 1e-12;
+
+    fn assert_vec_f64_eq(a: &[f64], b: &[f64]) {
+        assert_eq!(a.len(), b.len(), "length mismatch");
+        for (i, (x, y)) in a.iter().zip(b.iter()).enumerate() {
+            assert!((*x - *y).abs() < EPS, "index {i} differs: {x} vs {y}");
+        }
+    }
+
+    // Constructors
+
+    #[test]
+    fn from_cols_basic() {
+        let m = Matrix::from_cols(vec![vec![1, 2], vec![3, 4]]);
+        assert_eq!(m.rows(), 2);
+        assert_eq!(m.cols(), 2);
+        assert_eq!(m[(0, 0)], 1);
+        assert_eq!(m[(1, 0)], 2);
+        assert_eq!(m[(0, 1)], 3);
+        assert_eq!(m[(1, 1)], 4);
+    }
+
+    #[test]
+    #[should_panic(expected = "need at least one column")]
+    fn from_cols_zero_columns_panics() {
+        let _ = Matrix::<i32>::from_cols(vec![]);
+    }
+
+    #[test]
+    #[should_panic(expected = "col 1")]
+    fn from_cols_mismatched_lengths_panics() {
+        let _ = Matrix::from_cols(vec![vec![1, 2], vec![3]]);
+    }
+
+    #[test]
+    fn from_vec_basic() {
+        // column‑major order: (r,c) = value
+        // (0,0)=1 (1,0)=2 (0,1)=3 (1,1)=4 (0,2)=5 (1,2)=6
+        let data = vec![1, 2, 3, 4, 5, 6];
+        let m = Matrix::from_vec(data, 2, 3);
+        assert_eq!(m[(0, 2)], 5);
+        assert_eq!(m[(1, 2)], 6);
+    }
+
+    // Indexing & mutation
+
+    #[test]
+    fn index_mut_works() {
+        let mut m = Matrix::from_cols(vec![vec![1, 2]]);
+        *m.get_mut(0, 0) = 10;
+        assert_eq!(m[(0, 0)], 10);
+    }
+
+    #[test]
+    #[should_panic(expected = "index out of bounds")]
+    fn index_out_of_bounds_panics() {
+        let m = Matrix::from_cols(vec![vec![1]]);
+        let _ = m[(1, 0)];
+    }
+
+    // Column swapping
+
+    #[test]
+    fn swap_columns_basic() {
+        let mut m = Matrix::from_cols(vec![vec![1, 2], vec![3, 4]]);
+        m.swap_columns(0, 1);
+        let expected = Matrix::from_cols(vec![vec![3, 4], vec![1, 2]]);
+        assert_eq!(m, expected);
+    }
+
+    // ── Element‑wise ops ─
+
+    #[test]
+    fn elementwise_add_sub_mul_div() {
+        let a = Matrix::from_cols(vec![vec![1, 2], vec![3, 4]]);
+        let b = Matrix::from_cols(vec![vec![10, 20], vec![30, 40]]);
+
+        assert_eq!(&a + &b, Matrix::from_cols(vec![vec![11, 22], vec![33, 44]]));
+        assert_eq!(&b - &a, Matrix::from_cols(vec![vec![9, 18], vec![27, 36]]));
+        assert_eq!(
+            &a * &b,
+            Matrix::from_cols(vec![vec![10, 40], vec![90, 160]])
+        );
+        assert_eq!(&b / &a, Matrix::from_cols(vec![vec![10, 10], vec![10, 10]]));
+    }
+
+    // f64‑specific helpers
+
+    #[test]
+    fn reductions_with_nan() {
+        let m = Matrix::from_cols(vec![vec![1.0, NAN, 3.0], vec![4.0, 5.0, NAN]]);
+        // Matrix: 3 rows × 2 columns
+        assert_vec_f64_eq(&m.sum_vertical(), &[4.0, 9.0]);
+        assert_vec_f64_eq(&m.sum_horizontal(), &[5.0, 5.0, 3.0]);
+        assert_vec_f64_eq(&m.prod_vertical(), &[3.0, 20.0]);
+        assert_vec_f64_eq(&m.prod_horizontal(), &[4.0, 5.0, 3.0]);
+
+        assert_eq!(m.count_nan_vertical(), vec![1, 1]);
+        assert_eq!(m.count_nan_horizontal(), vec![0, 1, 1]);
+    }
+
+    #[test]
+    fn apply_axis_dispatch() {
+        let m = Matrix::from_cols(vec![vec![1.0, 2.0], vec![3.0, 4.0]]);
+        let col_sums = m.apply_axis(Axis::Col, |col| col.iter().sum::<f64>());
+        let row_sums = m.apply_axis(Axis::Row, |row| row.iter().sum::<f64>());
+        assert_vec_f64_eq(&col_sums, &[3.0, 7.0]);
+        assert_vec_f64_eq(&row_sums, &[4.0, 6.0]);
+    }
+
+    #[test]
+    fn is_nan_mask() {
+        let m = Matrix::from_cols(vec![vec![1.0, NAN]]);
+        let expected = Matrix::from_cols(vec![vec![false, true]]);
+        assert_eq!(m.is_nan(), expected);
+    }
+}