Merge branch 'main' into dataframe

.github/workflows/docs-and-testcov.yml

@@ -105,10 +105,21 @@ jobs:
           > last-commit-date.json
 
       - name: Download last available benchmark report
+        env:
+          GH_TOKEN: ${{ secrets.CUSTOM_GH_TOKEN }}
         run: |
-          artifact_url=$(gh api -H "Accept: application/vnd.github+json" \
+          artifact_url=$(
-            /repos/${{ github.repository }}/actions/artifacts \
+            curl -sSL \
-            | jq -r '.artifacts[] | select(.name | startswith("benchmark-reports")) | .archive_download_url' | head -n 1)
+              -H "Accept: application/vnd.github+json" \
+              -H "Authorization: Bearer ${GH_TOKEN}" \
+              "https://api.github.com/repos/${{ github.repository }}/actions/artifacts" \
+            | jq -r '
+                .artifacts[]
+                | select(.name | startswith("benchmark-reports"))
+                | .archive_download_url
+              ' \
+            | head -n 1
+          )
 
           if [ -z "$artifact_url" ]; then
             echo "No benchmark artifact found!"
@@ -117,7 +128,7 @@ jobs:
             exit 0
           fi
 
-          curl -L -H "Authorization: Bearer ${{ secrets.CUSTOM_GH_TOKEN }}" \
+          curl -L -H "Authorization: Bearer ${GH_TOKEN}" \
           "$artifact_url" -o benchmark-report.zip
 
           # Print all files in the current directory

Cargo.toml

@@ -15,6 +15,9 @@ crate-type = ["cdylib", "lib"]
 chrono = "^0.4.10"
 criterion = { version = "0.5", features = ["html_reports"], optional = true }
 
+[dev-dependencies]
+rand = "^0.9.1"
+
 [features]
 bench = ["dep:criterion"]
 

README.md

@@ -1,4 +1,5 @@
-# <img align="center" alt="Rustframe" src=".github/rustframe_logo.png" height="50" /> rustframe
+
+# <img align="center" alt="Rustframe" src=".github/rustframe_logo.png" height="50px" /> rustframe
 
 <!-- though the centre tag doesn't work as it would noramlly, it achieves the desired effect -->
 
@@ -229,3 +230,15 @@ println!(
 ### More examples
 
 See the [examples](./examples/) directory for some demonstrations of Rustframe's syntax and functionality.
+
+To run the examples, use:
+
+```bash
+cargo run --example <example_name>
+```
+
+E.g. to run the `game_of_life` example:
+
+```bash
+cargo run --example game_of_life
+```

benches/benchmarks.rs

@@ -109,6 +109,47 @@ fn matrix_operations_benchmark(c: &mut Criterion, sizes: &[usize]) {
                 let _result = &ma / 2.0;
             });
         });
+        c.bench_function(
+            &format!("matrix matrix_multiply ({}x{})", size, size),
+            |b| {
+                b.iter(|| {
+                    let _result = ma.matrix_mul(&ma);
+                });
+            },
+        );
+        c.bench_function(&format!("matrix sum_horizontal ({}x{})", size, size), |b| {
+            b.iter(|| {
+                let _result = ma.sum_horizontal();
+            });
+        });
+        c.bench_function(&format!("matrix sum_vertical ({}x{})", size, size), |b| {
+            b.iter(|| {
+                let _result = ma.sum_vertical();
+            });
+        });
+        c.bench_function(
+            &format!("matrix prod_horizontal ({}x{})", size, size),
+            |b| {
+                b.iter(|| {
+                    let _result = ma.prod_horizontal();
+                });
+            },
+        );
+        c.bench_function(&format!("matrix prod_vertical ({}x{})", size, size), |b| {
+            b.iter(|| {
+                let _result = ma.prod_vertical();
+            });
+        });
+        c.bench_function(&format!("matrix apply_axis ({}x{})", size, size), |b| {
+            b.iter(|| {
+                let _result = ma.apply_axis(0, |col| col.iter().sum::<f64>());
+            });
+        });
+        c.bench_function(&format!("matrix transpose ({}x{})", size, size), |b| {
+            b.iter(|| {
+                let _result = ma.transpose();
+            });
+        });
     }
 
     for &size in sizes {
@@ -187,6 +228,12 @@ fn benchmark_frame_operations(c: &mut Criterion, sizes: &[usize]) {
             });
         });
 
+        c.bench_function(&format!("frame matrix_multiply ({}x{})", size, size), |b| {
+            b.iter(|| {
+                let _result = fa.matrix_mul(&fb);
+            });
+        });
+
         c.bench_function(&format!("frame sum_horizontal ({}x{})", size, size), |b| {
             b.iter(|| {
                 let _result = fa.sum_horizontal();
@@ -207,6 +254,16 @@ fn benchmark_frame_operations(c: &mut Criterion, sizes: &[usize]) {
                 let _result = fa.prod_vertical();
             });
         });
+        c.bench_function(&format!("frame apply_axis ({}x{})", size, size), |b| {
+            b.iter(|| {
+                let _result = fa.apply_axis(0, |col| col.iter().sum::<f64>());
+            });
+        });
+        c.bench_function(&format!("frame transpose ({}x{})", size, size), |b| {
+            b.iter(|| {
+                let _result = fa.transpose();
+            });
+        });
     }
 }
 

examples/game_of_life.rs

@@ -1,7 +1,113 @@
-// src/gol.rs
-
 use rand::{self, Rng};
-use rustframe::matrix::{BoolMatrix, IntMatrix, Matrix};
+use rustframe::matrix::{BoolMatrix, BoolOps, IntMatrix, Matrix};
+use std::{thread, time};
+
+const BOARD_SIZE: usize = 50; // Size of the board (50x50)
+const TICK_DURATION_MS: u64 = 10; // Milliseconds per frame
+
+fn main() {
+    // Initialize the game board.
+    // This demonstrates `BoolMatrix::from_vec`.
+    let mut current_board =
+        BoolMatrix::from_vec(vec![false; BOARD_SIZE * BOARD_SIZE], BOARD_SIZE, BOARD_SIZE);
+
+    let primes = generate_primes((BOARD_SIZE * BOARD_SIZE) as i32);
+
+    add_simulated_activity(&mut current_board, BOARD_SIZE);
+
+    let mut generation_count: u32 = 0;
+    // `previous_board_state` will store a clone of the board.
+    // This demonstrates `Matrix::clone()` and later `PartialEq` for `Matrix`.
+    let mut previous_board_state: Option<BoolMatrix> = None;
+    let mut board_hashes = Vec::new();
+    // let mut print_board_bool = true;
+    let mut print_bool_int = 0;
+
+    loop {
+        // print!("{}[2J", 27 as char); // Clear screen and move cursor to top-left
+
+        // if print_board_bool {
+        if print_bool_int % 10 == 0 {
+            print!("{}[2J", 27 as char);
+            println!("Conway's Game of Life - Generation: {}", generation_count);
+
+            print_board(&current_board);
+            println!("Alive cells: {}", &current_board.count());
+
+            // print_board_bool = false;
+            print_bool_int = 0;
+        } else {
+            // print_board_bool = true;
+            print_bool_int += 1;
+        }
+        // `current_board.count()` demonstrates a method from `BoolOps`.
+        board_hashes.push(hash_board(&current_board, primes.clone()));
+        if detect_stable_state(&current_board, &previous_board_state) {
+            println!(
+                "\nStable state detected at generation {}.",
+                generation_count
+            );
+            add_simulated_activity(&mut current_board, BOARD_SIZE);
+        }
+        if detect_repeating_state(&mut board_hashes) {
+            println!(
+                "\nRepeating state detected at generation {}.",
+                generation_count
+            );
+            add_simulated_activity(&mut current_board, BOARD_SIZE);
+        }
+        if !&current_board.any() {
+            println!("\nExtinction at generation {}.", generation_count);
+            add_simulated_activity(&mut current_board, BOARD_SIZE);
+        }
+
+        // `current_board.clone()` demonstrates `Clone` for `Matrix`.
+        previous_board_state = Some(current_board.clone());
+
+        // This is the core call to your game logic.
+        let next_board = game_of_life_next_frame(&current_board);
+        current_board = next_board;
+
+        generation_count += 1;
+        thread::sleep(time::Duration::from_millis(TICK_DURATION_MS));
+
+        // if generation_count > 500 { // Optional limit
+        //     println!("\nReached generation limit.");
+        //     break;
+        // }
+    }
+}
+
+/// Prints the Game of Life board to the console.
+///
+/// - `board`: A reference to the `BoolMatrix` representing the current game state.
+/// This function demonstrates `board.rows()`, `board.cols()`, and `board[(r, c)]` (Index trait).
+fn print_board(board: &BoolMatrix) {
+    let mut print_str = String::new();
+    print_str.push_str("+");
+    for _ in 0..board.cols() {
+        print_str.push_str("--");
+    }
+    print_str.push_str("+\n");
+    for r in 0..board.rows() {
+        print_str.push_str("| ");
+        for c in 0..board.cols() {
+            if board[(r, c)] {
+                // Using Index trait for Matrix<bool>
+                print_str.push_str("██");
+            } else {
+                print_str.push_str("  ");
+            }
+        }
+        print_str.push_str(" |\n");
+    }
+    print_str.push_str("+");
+    for _ in 0..board.cols() {
+        print_str.push_str("--");
+    }
+    print_str.push_str("+\n\n");
+    print!("{}", print_str);
+}
 
 /// Helper function to create a shifted version of the game board.
 /// (Using the version provided by the user)

src/frame/base.rs

@@ -483,6 +483,12 @@ impl<T: Clone + PartialEq> Frame<T> {
         deleted_data
     }
 
+
+    /// Returns a new `Matrix` that is the transpose of the current frame's matrix.
+    pub fn transpose(&self) -> Matrix<T> {
+        self.matrix.transpose()
+    }
+
     /// Sorts columns alphabetically by name, preserving data associations.
     pub fn sort_columns(&mut self) {
         let n = self.column_names.len();

src/frame/ops.rs

@@ -20,6 +20,13 @@ impl SeriesOps for Frame<f64> {
     {
         self.matrix().apply_axis(axis, f)
     }
+    fn matrix_mul(&self, other: &Self) -> FloatMatrix {
+        self.matrix().matrix_mul(other.matrix())
+    }
+
+    fn dot(&self, other: &Self) -> FloatMatrix {
+        self.matrix().dot(other.matrix())
+    }
 
     delegate_to_matrix!(
         sum_vertical -> Vec<f64>,
@@ -128,6 +135,17 @@ mod tests {
         );
         assert_eq!(frame.is_nan(), frame.matrix().is_nan());
         assert_eq!(frame.apply_axis(Axis::Row, |x| x[0] + x[1]), vec![4.0, 6.0]);
+
+
+        assert_eq!(frame.matrix_mul(&frame), frame.matrix().matrix_mul(&frame.matrix()));
+        assert_eq!(frame.dot(&frame), frame.matrix().dot(&frame.matrix()));
+        
+        // test transpose - returns a matrix.
+        let frame_transposed_mat = frame.transpose();
+        let frame_mat_transposed = frame.matrix().transpose();
+        assert_eq!(frame_transposed_mat, frame_mat_transposed);
+        assert_eq!(frame.matrix(), &frame.matrix().transpose().transpose());
+
     }
     #[test]
 
@@ -152,4 +170,7 @@ mod tests {
             vec![false, false]
         );
     }
+
+
+
 }

src/matrix/mat.rs

@@ -168,7 +168,12 @@ impl<T: Clone> Matrix<T> {
     /// Deletes a column from the matrix. Panics on out-of-bounds.
     /// This is O(N) where N is the number of elements.
     pub fn delete_column(&mut self, col: usize) {
-        assert!(col < self.cols, "column index {} out of bounds for {} columns", col, self.cols);
+        assert!(
+            col < self.cols,
+            "column index {} out of bounds for {} columns",
+            col,
+            self.cols
+        );
         let start = col * self.rows;
         self.data.drain(start..start + self.rows); // Efficient removal
         self.cols -= 1;
@@ -203,6 +208,22 @@ impl<T: Clone> Matrix<T> {
         self.data = new_data;
         self.rows = new_rows;
     }
+
+    pub fn transpose(&self) -> Matrix<T> {
+        let (m, n) = (self.rows, self.cols);
+        let mut transposed_data = Vec::with_capacity(m * n);
+
+        // In the transposed matrix the old rows become the new columns.
+        for j in 0..m {
+            // new column index = old row index
+            for i in 0..n {
+                // new row index = old col index
+                transposed_data.push(self[(j, i)].clone()); // A(T)[i,j] = A[j,i]
+            }
+        }
+
+        Matrix::from_vec(transposed_data, n, m) // size is n × m
+    }
 }
 
 impl<T: Clone> Matrix<T> {
@@ -238,8 +259,19 @@ impl<T: Clone> Matrix<T> {
     /// Adds a row to the matrix at the specified index. Panics if index > rows or length mismatch.
     /// This is O(N) where N is the number of elements, as it rebuilds the data vec.
     pub fn add_row(&mut self, index: usize, row: Vec<T>) {
-        assert!(index <= self.rows, "add_row index {} out of bounds for {} rows", index, self.rows);
+        assert!(
-        assert_eq!(row.len(), self.cols, "row length mismatch: expected {} (cols), got {}", self.cols, row.len());
+            index <= self.rows,
+            "add_row index {} out of bounds for {} rows",
+            index,
+            self.rows
+        );
+        assert_eq!(
+            row.len(),
+            self.cols,
+            "row length mismatch: expected {} (cols), got {}",
+            self.cols,
+            row.len()
+        );
 
         if self.cols == 0 && self.rows == 0 {
             // Special case: adding first row to empty matrix
@@ -624,7 +656,6 @@ pub type BoolMatrix = Matrix<bool>;
 pub type IntMatrix = Matrix<i32>;
 pub type StringMatrix = Matrix<String>;
 
-
 // --- Unit Tests ---
 
 #[cfg(test)]
@@ -903,6 +934,40 @@ mod tests {
         assert_eq!(matrix[(1, 2)], 6); // Second row, third col
     }
 
+    #[test]
+    fn test_transpose() {
+        let matrix = static_test_matrix();
+        let transposed = matrix.transpose();
+        let round_triped = transposed.transpose();
+        assert_eq!(
+            round_triped, matrix,
+            "Transposing twice should return original matrix"
+        );
+        for r in 0..matrix.rows() {
+            for c in 0..matrix.cols() {
+                assert_eq!(matrix[(r, c)], transposed[(c, r)]);
+            }
+        }
+    }
+
+    #[test]
+    fn test_transpose_big() {
+        let data: Vec<i32> = (1..=20000).collect(); //
+        let matrix = Matrix::from_vec(data, 100, 200);
+        let transposed = matrix.transpose();
+        assert_eq!(transposed.rows(), 200);
+        assert_eq!(transposed.cols(), 100);
+        assert_eq!(transposed.data().len(), 20000);
+        assert_eq!(transposed[(0, 0)], 1);
+
+        let round_trip = transposed.transpose();
+
+        assert_eq!(
+            round_trip, matrix,
+            "Transposing back should return original matrix"
+        );
+    }
+
     #[test]
     #[should_panic(expected = "data length mismatch")]
     fn test_from_vec_wrong_length() {
@@ -999,20 +1064,20 @@ mod tests {
     #[test]
     #[should_panic(expected = "index out of bounds")]
     fn test_index_out_of_bounds_row_alt() {
-        let matrix = static_test_matrix(); // 3x3
+        let matrix = static_test_matrix();
         let _ = matrix[(3, 0)];
     }
 
     #[test]
     #[should_panic(expected = "index out of bounds")]
     fn test_index_out_of_bounds_col_alt() {
-        let matrix = static_test_matrix(); // 3x3
+        let matrix = static_test_matrix();
         let _ = matrix[(0, 3)];
     }
 
     #[test]
     fn test_index_mut_and_get_mut() {
-        let mut matrix = static_test_matrix(); // 3x3
+        let mut matrix = static_test_matrix();
 
         matrix[(0, 0)] = 10;
         matrix[(1, 1)] = 20;
@@ -1028,33 +1093,26 @@ mod tests {
         assert_eq!(matrix[(0, 1)], 15);
         assert_eq!(matrix[(2, 1)], 25);
 
-        // Check underlying data consistency (column-major)
-        // Should be:
-        // 10 15  7
-        //  2 20  8
-        //  3 25 30
         assert_eq!(matrix.data(), &[10, 2, 3, 15, 20, 25, 7, 8, 30]);
     }
 
     #[test]
     #[should_panic(expected = "index out of bounds")]
     fn test_index_mut_out_of_bounds_row() {
-        let mut matrix = static_test_matrix(); // 3x3
+        let mut matrix = static_test_matrix();
         matrix[(3, 0)] = 99;
     }
 
     #[test]
     #[should_panic(expected = "index out of bounds")]
     fn test_index_mut_out_of_bounds_col() {
-        let mut matrix = static_test_matrix(); // 3x3
+        let mut matrix = static_test_matrix();
         matrix[(0, 3)] = 99;
     }
 
     #[test]
     fn test_column() {
-        let matrix = static_test_matrix_2x4(); // 2x4
+        let matrix = static_test_matrix_2x4();
-        // 1 3 5 7
-        // 2 4 6 8
 
         assert_eq!(matrix.column(0), &[1, 2]);
         assert_eq!(matrix.column(1), &[3, 4]);
@@ -1065,15 +1123,13 @@ mod tests {
     #[test]
     #[should_panic(expected = "column index 4 out of bounds for 4 columns")]
     fn test_column_out_of_bounds() {
-        let matrix = static_test_matrix_2x4(); // 2x4
+        let matrix = static_test_matrix_2x4();
         matrix.column(4);
     }
 
     #[test]
     fn test_column_mut() {
-        let mut matrix = static_test_matrix_2x4(); // 2x4
+        let mut matrix = static_test_matrix_2x4();
-        // 1 3 5 7
-        // 2 4 6 8
 
         let col1_mut = matrix.column_mut(1);
         col1_mut[0] = 30;
@@ -1088,25 +1144,19 @@ mod tests {
         assert_eq!(matrix[(0, 3)], 70);
         assert_eq!(matrix[(1, 3)], 8); // Unchanged
 
-        // Check underlying data (column-major)
-        // Should be:
-        // 1 30 5 70
-        // 2 40 6  8
         assert_eq!(matrix.data(), &[1, 2, 30, 40, 5, 6, 70, 8]);
     }
 
     #[test]
     #[should_panic(expected = "column index 4 out of bounds for 4 columns")]
     fn test_column_mut_out_of_bounds() {
-        let mut matrix = static_test_matrix_2x4(); // 2x4
+        let mut matrix = static_test_matrix_2x4();
         matrix.column_mut(4);
     }
 
     #[test]
     fn test_iter_columns() {
-        let matrix = static_test_matrix_2x4(); // 2x4
+        let matrix = static_test_matrix_2x4();
-        // 1 3 5 7
-        // 2 4 6 8
 
         let cols: Vec<&[i32]> = matrix.iter_columns().collect();
         assert_eq!(cols.len(), 4);
@@ -1118,9 +1168,7 @@ mod tests {
 
     #[test]
     fn test_iter_rows() {
-        let matrix = static_test_matrix_2x4(); // 2x4
+        let matrix = static_test_matrix_2x4();
-        // 1 3 5 7
-        // 2 4 6 8
 
         let rows: Vec<Vec<i32>> = matrix
             .iter_rows()
@@ -1134,10 +1182,7 @@ mod tests {
     // test data_mut
     #[test]
     fn test_data_mut() {
-        let mut matrix = static_test_matrix(); // 3x3
+        let mut matrix = static_test_matrix();
-        // 1 4 7
-        // 2 5 8
-        // 3 6 9
 
         let data_mut = matrix.data_mut();
         data_mut[0] = 10;
@@ -1149,10 +1194,7 @@ mod tests {
 
     #[test]
     fn test_matrix_row_get_and_iter() {
-        let matrix = static_test_matrix_2x4(); // 2x4
+        let matrix = static_test_matrix_2x4();
-        // 1 3 5 7
-        // 2 4 6 8
-
         let row0 = matrix.iter_rows().next().unwrap();
         assert_eq!(*row0.get(0), 1);
         assert_eq!(*row0.get(1), 3);
@@ -1169,17 +1211,9 @@ mod tests {
 
     #[test]
     fn test_swap_columns() {
-        let mut matrix = static_test_matrix(); // 3x3
+        let mut matrix = static_test_matrix();
-        // 1 4 7
-        // 2 5 8
-        // 3 6 9
 
-        matrix.swap_columns(0, 2); // Swap first and last
+        matrix.swap_columns(0, 2); // swap first and last
-
-        // Should be:
-        // 7 4 1
-        // 8 5 2
-        // 9 6 3
 
         assert_eq!(matrix.rows(), 3);
         assert_eq!(matrix.cols(), 3);
@@ -1193,7 +1227,7 @@ mod tests {
         assert_eq!(matrix[(1, 2)], 2);
         assert_eq!(matrix[(2, 2)], 3);
 
-        // Swap the same column (should do nothing)
+        // swap the same column (should do nothing)
         let original_data = matrix.data().to_vec();
         matrix.swap_columns(1, 1);
         assert_eq!(matrix.data(), &original_data); // Data should be identical
@@ -1205,22 +1239,15 @@ mod tests {
     #[test]
     #[should_panic(expected = "column index c2=3 out of bounds for 3 columns")]
     fn test_swap_columns_out_of_bounds() {
-        let mut matrix = static_test_matrix(); // 3x3
+        let mut matrix = static_test_matrix();
         matrix.swap_columns(0, 3);
     }
 
     #[test]
     fn test_delete_column() {
-        let mut matrix = static_test_matrix_2x4(); // 2x4
+        let mut matrix = static_test_matrix_2x4();
-        // 1 3 5 7
-        // 2 4 6 8
-
         matrix.delete_column(1); // Delete the second column (index 1)
 
-        // Should be:
-        // 1 5 7
-        // 2 6 8
-
         assert_eq!(matrix.rows(), 2);
         assert_eq!(matrix.cols(), 3);
         assert_eq!(matrix[(0, 0)], 1);
@@ -1230,23 +1257,17 @@ mod tests {
         assert_eq!(matrix[(0, 2)], 7);
         assert_eq!(matrix[(1, 2)], 8);
 
-        // Check underlying data (column-major)
+        // check underlying data
         assert_eq!(matrix.data(), &[1, 2, 5, 6, 7, 8]);
 
         // Delete the first column
         matrix.delete_column(0);
-        // Should be:
-        // 5 7
-        // 6 8
         assert_eq!(matrix.rows(), 2);
         assert_eq!(matrix.cols(), 2);
         assert_eq!(matrix.data(), &[5, 6, 7, 8]);
 
         // Delete the last column
         matrix.delete_column(1);
-        // Should be:
-        // 5
-        // 6
         assert_eq!(matrix.rows(), 2);
         assert_eq!(matrix.cols(), 1);
         assert_eq!(matrix.data(), &[5, 6]);
@@ -1262,22 +1283,15 @@ mod tests {
     #[test]
     #[should_panic(expected = "column index 4 out of bounds for 4 columns")]
     fn test_delete_column_out_of_bounds() {
-        let mut matrix = static_test_matrix_2x4(); // 2x4
+        let mut matrix = static_test_matrix_2x4();
         matrix.delete_column(4);
     }
 
     #[test]
     fn test_delete_row() {
-        let mut matrix = static_test_matrix(); // 3x3
+        let mut matrix = static_test_matrix();
-        // 1 4 7
-        // 2 5 8
-        // 3 6 9
 
-        matrix.delete_row(1); // Delete the second row (index 1)
+        matrix.delete_row(1); // Delete the second row
-
-        // Should be:
-        // 1 4 7
-        // 3 6 9
 
         assert_eq!(matrix.rows(), 2);
         assert_eq!(matrix.cols(), 3);
@@ -1288,9 +1302,7 @@ mod tests {
         assert_eq!(matrix[(0, 2)], 7);
         assert_eq!(matrix[(1, 2)], 9);
 
-        // Check underlying data (column-major)
+        // check underlying data (column-major)
-        // Original: [1, 2, 3, 4, 5, 6, 7, 8, 9]
-        // Delete row 1: [1, 3, 4, 6, 7, 9]
         assert_eq!(matrix.data(), &[1, 3, 4, 6, 7, 9]);
 
         // Delete the first row
@@ -1312,22 +1324,15 @@ mod tests {
     #[test]
     #[should_panic(expected = "row index 3 out of bounds for 3 rows")]
     fn test_delete_row_out_of_bounds() {
-        let mut matrix = static_test_matrix(); // 3x3
+        let mut matrix = static_test_matrix();
         matrix.delete_row(3);
     }
 
     #[test]
     fn test_add_column() {
-        let mut matrix = static_test_matrix_2x4(); // 2x4
+        let mut matrix = static_test_matrix_2x4();
-        // 1 3 5 7
-        // 2 4 6 8
-
         let new_col = vec![9, 10];
-        matrix.add_column(2, new_col); // Add at index 2
+        matrix.add_column(2, new_col);
-
-        // Should be:
-        // 1 3 9 5 7
-        // 2 4 10 6 8
 
         assert_eq!(matrix.rows(), 2);
         assert_eq!(matrix.cols(), 5);
@@ -1342,17 +1347,12 @@ mod tests {
         assert_eq!(matrix[(0, 4)], 7); // Shifted
         assert_eq!(matrix[(1, 4)], 8);
 
-        // Check underlying data (column-major)
+        // Check underlying data
-        // Original: [1, 2, 3, 4, 5, 6, 7, 8]
-        // Add [9, 10] at index 2: [1, 2, 3, 4, 9, 10, 5, 6, 7, 8]
         assert_eq!(matrix.data(), &[1, 2, 3, 4, 9, 10, 5, 6, 7, 8]);
 
         // Add a column at the beginning
         let new_col_start = vec![11, 12];
         matrix.add_column(0, new_col_start);
-        // Should be:
-        // 11 1 3 9 5 7
-        // 12 2 4 10 6 8
         assert_eq!(matrix.rows(), 2);
         assert_eq!(matrix.cols(), 6);
         assert_eq!(matrix[(0, 0)], 11);
@@ -1362,9 +1362,6 @@ mod tests {
         // Add a column at the end
         let new_col_end = vec![13, 14];
         matrix.add_column(6, new_col_end);
-        // Should be:
-        // 11 1 3 9 5 7 13
-        // 12 2 4 10 6 8 14
         assert_eq!(matrix.rows(), 2);
         assert_eq!(matrix.cols(), 7);
         assert_eq!(matrix[(0, 6)], 13);
@@ -1378,7 +1375,7 @@ mod tests {
     #[test]
     #[should_panic(expected = "add_column index 5 out of bounds for 4 columns")]
     fn test_add_column_out_of_bounds() {
-        let mut matrix = static_test_matrix_2x4(); // 2x4
+        let mut matrix = static_test_matrix_2x4();
         let new_col = vec![9, 10];
         matrix.add_column(5, new_col); // Index 5 is out of bounds for 4 columns
     }
@@ -1386,24 +1383,16 @@ mod tests {
     #[test]
     #[should_panic(expected = "column length mismatch")]
     fn test_add_column_length_mismatch() {
-        let mut matrix = static_test_matrix_2x4(); // 2x4 (2 rows)
+        let mut matrix = static_test_matrix_2x4();
         let new_col = vec![9, 10, 11]; // Wrong length
         matrix.add_column(0, new_col);
     }
 
     #[test]
     fn test_add_row() {
-        let mut matrix = static_test_matrix_2x4(); // 2x4
+        let mut matrix = static_test_matrix_2x4();
-        // 1 3 5 7
-        // 2 4 6 8
-
         let new_row = vec![9, 10, 11, 12];
-        matrix.add_row(1, new_row); // Add at index 1
+        matrix.add_row(1, new_row);
-
-        // Should be:
-        // 1  3  5  7
-        // 9 10 11 12
-        // 2  4  6  8
 
         assert_eq!(matrix.rows(), 3);
         assert_eq!(matrix.cols(), 4);
@@ -1422,23 +1411,11 @@ mod tests {
         assert_eq!(matrix[(2, 3)], 8);
 
         // Check underlying data (column-major)
-        // Original: [1, 2, 3, 4, 5, 6, 7, 8] (rows 0, 1)
-        // Add [9, 10, 11, 12] at index 1 (new row will be index 1, original row 1 becomes index 2)
-        // Col 0: [1, 9, 2]
-        // Col 1: [3, 10, 4]
-        // Col 2: [5, 11, 6]
-        // Col 3: [7, 12, 8]
-        // Data: [1, 9, 2, 3, 10, 4, 5, 11, 6, 7, 12, 8]
         assert_eq!(matrix.data(), &[1, 9, 2, 3, 10, 4, 5, 11, 6, 7, 12, 8]);
 
         // Add a row at the beginning
         let new_row_start = vec![13, 14, 15, 16];
         matrix.add_row(0, new_row_start);
-        // Should be:
-        // 13 14 15 16
-        // 1  3  5  7
-        // 9 10 11 12
-        // 2  4  6  8
         assert_eq!(matrix.rows(), 4);
         assert_eq!(matrix.cols(), 4);
         assert_eq!(matrix[(0, 0)], 13);
@@ -1452,12 +1429,6 @@ mod tests {
         // Add a row at the end
         let new_row_end = vec![17, 18, 19, 20];
         matrix.add_row(4, new_row_end);
-        // Should be:
-        // 13 14 15 16
-        // 1  3  5  7
-        // 9 10 11 12
-        // 2  4  6  8
-        // 17 18 19 20
         assert_eq!(matrix.rows(), 5);
         assert_eq!(matrix.cols(), 4);
         assert_eq!(matrix[(4, 0)], 17);
@@ -1467,7 +1438,7 @@ mod tests {
     #[test]
     #[should_panic(expected = "add_row index 3 out of bounds for 2 rows")]
     fn test_add_row_out_of_bounds() {
-        let mut matrix = static_test_matrix_2x4(); // 2x4
+        let mut matrix = static_test_matrix_2x4();
         let new_row = vec![9, 10, 11, 12];
         matrix.add_row(3, new_row); // Index 3 is out of bounds for 2 rows
     }
@@ -1475,26 +1446,22 @@ mod tests {
     #[test]
     #[should_panic(expected = "row length mismatch")]
     fn test_add_row_length_mismatch() {
-        let mut matrix = static_test_matrix_2x4(); // 2x4 (4 cols)
+        let mut matrix = static_test_matrix_2x4();
         let new_row = vec![9, 10, 11]; // Wrong length
         matrix.add_row(0, new_row);
     }
 
     #[test]
     fn test_elementwise_add() {
-        let matrix1 = static_test_matrix(); // 3x3
+        let matrix1 = static_test_matrix();
-        let matrix2 = Matrix::from_vec(vec![9, 8, 7, 6, 5, 4, 3, 2, 1], 3, 3); // 3x3
+        let matrix2 = Matrix::from_vec(vec![9, 8, 7, 6, 5, 4, 3, 2, 1], 3, 3);
 
         let result = &matrix1 + &matrix2;
 
         assert_eq!(result.rows(), 3);
         assert_eq!(result.cols(), 3);
 
-        // Expected:
+        // Expect all 10s
-        // 1+9  4+6  7+3  => 10 10 10
-        // 2+8  5+5  8+2  => 10 10 10
-        // 3+7  6+4  9+1  => 10 10 10
-        // Column-major data: [10, 10, 10, 10, 10, 10, 10, 10, 10]
         assert_eq!(result.data(), &[10, 10, 10, 10, 10, 10, 10, 10, 10]);
         assert_eq!(result[(0, 0)], 10);
         assert_eq!(result[(1, 1)], 10);
@@ -1503,19 +1470,14 @@ mod tests {
 
     #[test]
     fn test_elementwise_sub() {
-        let matrix1 = static_test_matrix(); // 3x3
+        let matrix1 = static_test_matrix();
-        let matrix2 = Matrix::from_vec(vec![1, 1, 1, 2, 2, 2, 3, 3, 3], 3, 3); // 3x3
+        let matrix2 = Matrix::from_vec(vec![1, 1, 1, 2, 2, 2, 3, 3, 3], 3, 3);
 
         let result = &matrix1 - &matrix2;
 
         assert_eq!(result.rows(), 3);
         assert_eq!(result.cols(), 3);
 
-        // Expected:
-        // 1-1  4-2  7-3  => 0 2 4
-        // 2-1  5-2  8-3  => 1 3 5
-        // 3-1  6-2  9-3  => 2 4 6
-        // Column-major data: [0, 1, 2, 2, 3, 4, 4, 5, 6]
         assert_eq!(result.data(), &[0, 1, 2, 2, 3, 4, 4, 5, 6]);
         assert_eq!(result[(0, 0)], 0);
         assert_eq!(result[(1, 1)], 3);
@@ -1524,19 +1486,15 @@ mod tests {
 
     #[test]
     fn test_elementwise_mul() {
-        let matrix1 = static_test_matrix(); // 3x3
+        let matrix1 = static_test_matrix();
-        let matrix2 = Matrix::from_vec(vec![1, 2, 3, 1, 2, 3, 1, 2, 3], 3, 3); // 3x3
+        let matrix2 = Matrix::from_vec(vec![1, 2, 3, 1, 2, 3, 1, 2, 3], 3, 3);
 
         let result = &matrix1 * &matrix2;
 
         assert_eq!(result.rows(), 3);
         assert_eq!(result.cols(), 3);
 
-        // Expected:
+        // Expected
-        // 1*1  4*1  7*1  => 1 4 7
-        // 2*2  5*2  8*2  => 4 10 16
-        // 3*3  6*3  9*3  => 9 18 27
-        // Column-major data: [1, 4, 9, 4, 10, 18, 7, 16, 27]
         assert_eq!(result.data(), &[1, 4, 9, 4, 10, 18, 7, 16, 27]);
         assert_eq!(result[(0, 0)], 1);
         assert_eq!(result[(1, 1)], 10);
@@ -1545,19 +1503,14 @@ mod tests {
 
     #[test]
     fn test_elementwise_div() {
-        let matrix1 = static_test_matrix(); // 3x3
+        let matrix1 = static_test_matrix();
-        let matrix2 = Matrix::from_vec(vec![1, 1, 1, 2, 2, 2, 7, 8, 9], 3, 3); // 3x3
+        let matrix2 = Matrix::from_vec(vec![1, 1, 1, 2, 2, 2, 7, 8, 9], 3, 3);
 
         let result = &matrix1 / &matrix2; // Integer division
 
         assert_eq!(result.rows(), 3);
         assert_eq!(result.cols(), 3);
 
-        // Expected:
-        // 1/1  4/2  7/7  => 1 2 1
-        // 2/1  5/2  8/8  => 2 2 1  (integer division)
-        // 3/1  6/2  9/9  => 3 3 1
-        // Column-major data: [1, 2, 3, 2, 2, 3, 1, 1, 1]
         assert_eq!(result.data(), &[1, 2, 3, 2, 2, 3, 1, 1, 1]);
         assert_eq!(result[(0, 0)], 1);
         assert_eq!(result[(1, 1)], 2);
@@ -1567,34 +1520,26 @@ mod tests {
     #[test]
     #[should_panic(expected = "Row count mismatch: left has 3 rows, right has 2 rows")]
     fn test_elementwise_op_row_mismatch() {
-        let matrix1 = static_test_matrix(); // 3x3
+        let matrix1 = static_test_matrix();
-        let matrix2 = static_test_matrix_2x4(); // 2x4
+        let matrix2 = static_test_matrix_2x4();
         let _ = &matrix1 + &matrix2; // Should panic
     }
 
     #[test]
     #[should_panic(expected = "Row count mismatch: left has 3 rows, right has 2 ro")]
     fn test_elementwise_op_col_mismatch() {
-        let matrix1 = static_test_matrix(); // 3x3
+        let matrix1 = static_test_matrix();
-        let matrix2 = static_test_matrix_2x4(); // 2x4
+        let matrix2 = static_test_matrix_2x4();
         let _ = &matrix1 * &matrix2; // Should panic
     }
 
     #[test]
     fn test_bitwise_and() {
-        let data1 = vec![true, false, true, false, true, false]; // 2x3
+        let data1 = vec![true, false, true, false, true, false];
-        let data2 = vec![true, true, false, false, true, true]; // 2x3
+        let data2 = vec![true, true, false, false, true, true];
         let matrix1 = BoolMatrix::from_vec(data1, 2, 3);
         let matrix2 = BoolMatrix::from_vec(data2, 2, 3);
 
-        // Expected column-major results:
-        // T & T = T
-        // F & T = F
-        // T & F = F
-        // F & F = F
-        // T & T = T
-        // F & T = F
-        // Data: [T, F, F, F, T, F]
         let expected_data = vec![true, false, false, false, true, false];
         let expected_matrix = BoolMatrix::from_vec(expected_data, 2, 3);
 
@@ -1604,19 +1549,11 @@ mod tests {
 
     #[test]
     fn test_bitwise_or() {
-        let data1 = vec![true, false, true, false, true, false]; // 2x3
+        let data1 = vec![true, false, true, false, true, false];
-        let data2 = vec![true, true, false, false, true, true]; // 2x3
+        let data2 = vec![true, true, false, false, true, true];
         let matrix1 = BoolMatrix::from_vec(data1, 2, 3);
         let matrix2 = BoolMatrix::from_vec(data2, 2, 3);
 
-        // Expected column-major results:
-        // T | T = T
-        // F | T = T
-        // T | F = T
-        // F | F = F
-        // T | T = T
-        // F | T = T
-        // Data: [T, T, T, F, T, T]
         let expected_data = vec![true, true, true, false, true, true];
         let expected_matrix = BoolMatrix::from_vec(expected_data, 2, 3);
 
@@ -1626,19 +1563,11 @@ mod tests {
 
     #[test]
     fn test_bitwise_xor() {
-        let data1 = vec![true, false, true, false, true, false]; // 2x3
+        let data1 = vec![true, false, true, false, true, false];
-        let data2 = vec![true, true, false, false, true, true]; // 2x3
+        let data2 = vec![true, true, false, false, true, true];
         let matrix1 = BoolMatrix::from_vec(data1, 2, 3);
         let matrix2 = BoolMatrix::from_vec(data2, 2, 3);
 
-        // Expected column-major results:
-        // T ^ T = F
-        // F ^ T = T
-        // T ^ F = T
-        // F ^ F = F
-        // T ^ T = F
-        // F ^ T = T
-        // Data: [F, T, T, F, F, T]
         let expected_data = vec![false, true, true, false, false, true];
         let expected_matrix = BoolMatrix::from_vec(expected_data, 2, 3);
 
@@ -1648,17 +1577,9 @@ mod tests {
 
     #[test]
     fn test_bitwise_not() {
-        let data = vec![true, false, true, false, true, false]; // 2x3
+        let data = vec![true, false, true, false, true, false];
         let matrix = BoolMatrix::from_vec(data, 2, 3);
 
-        // Expected column-major results:
-        // !T = F
-        // !F = T
-        // !T = F
-        // !F = T
-        // !T = F
-        // !F = T
-        // Data: [F, T, F, T, F, T]
         let expected_data = vec![false, true, false, true, false, true];
         let expected_matrix = BoolMatrix::from_vec(expected_data, 2, 3);
 
@@ -1669,8 +1590,8 @@ mod tests {
     #[test]
     #[should_panic(expected = "Column count mismatch: left has 2 columns, right has 3 columns")]
     fn test_bitwise_op_row_mismatch() {
-        let data1 = vec![true, false, true, false]; // 2x2
+        let data1 = vec![true, false, true, false];
-        let data2 = vec![true, true, false, false, true, true]; // 2x3
+        let data2 = vec![true, true, false, false, true, true];
         let matrix1 = BoolMatrix::from_vec(data1, 2, 2);
         let matrix2 = BoolMatrix::from_vec(data2, 2, 3);
         let _ = &matrix1 & &matrix2; // Should panic
@@ -1679,8 +1600,8 @@ mod tests {
     #[test]
     #[should_panic(expected = "Column count mismatch: left has 2 columns, right has 3 columns")]
     fn test_bitwise_op_col_mismatch() {
-        let data1 = vec![true, false, true, false]; // 2x2
+        let data1 = vec![true, false, true, false];
-        let data2 = vec![true, true, false, false, true, true]; // 2x3
+        let data2 = vec![true, true, false, false, true, true];
         let matrix1 = BoolMatrix::from_vec(data1, 2, 2);
         let matrix2 = BoolMatrix::from_vec(data2, 2, 3);
         let _ = &matrix1 | &matrix2; // Should panic
@@ -1695,7 +1616,7 @@ mod tests {
             "c".to_string(),
             "d".to_string(),
         ];
-        let matrix = StringMatrix::from_vec(data.clone(), 2, 2); // 2x2
+        let matrix = StringMatrix::from_vec(data.clone(), 2, 2);
 
         assert_eq!(matrix[(0, 0)], "a".to_string());
         assert_eq!(matrix[(1, 0)], "b".to_string());
@@ -1707,12 +1628,10 @@ mod tests {
         matrix[(0, 0)] = "hello".to_string();
         assert_eq!(matrix[(0, 0)], "hello".to_string());
 
-        // Test add_column (requires Clone)
+        // Test add_column
         let new_col = vec!["e".to_string(), "f".to_string()];
-        matrix.add_column(1, new_col); // Add at index 1
+        matrix.add_column(1, new_col);
-        // Should be:
+
-        // hello c d
-        // b e f
         assert_eq!(matrix.rows(), 2);
         assert_eq!(matrix.cols(), 3);
         assert_eq!(matrix[(0, 0)], "hello".to_string());
@@ -1724,11 +1643,8 @@ mod tests {
 
         // Test add_row (requires Clone)
         let new_row = vec!["g".to_string(), "h".to_string(), "i".to_string()];
-        matrix.add_row(0, new_row); // Add at index 0
+        matrix.add_row(0, new_row);
-        // Should be:
+
-        // g h i
-        // hello e c
-        // b f d
         assert_eq!(matrix.rows(), 3);
         assert_eq!(matrix.cols(), 3);
         assert_eq!(matrix[(0, 0)], "g".to_string());
@@ -1740,8 +1656,8 @@ mod tests {
 
     #[test]
     fn test_float_matrix_ops() {
-        let data1 = vec![1.0, 2.0, 3.0, 4.0]; // 2x2
+        let data1 = vec![1.0, 2.0, 3.0, 4.0];
-        let data2 = vec![0.5, 1.5, 2.5, 3.5]; // 2x2
+        let data2 = vec![0.5, 1.5, 2.5, 3.5];
         let matrix1 = FloatMatrix::from_vec(data1, 2, 2);
         let matrix2 = FloatMatrix::from_vec(data2, 2, 2);
 
@@ -1750,17 +1666,13 @@ mod tests {
         let prod = &matrix1 * &matrix2;
         let div = &matrix1 / &matrix2;
 
-        // Check sums (col-major): [1.5, 3.5, 5.5, 7.5]
         assert_eq!(sum.data(), &[1.5, 3.5, 5.5, 7.5]);
 
-        // Check diffs (col-major): [0.5, 0.5, 0.5, 0.5]
         assert_eq!(diff.data(), &[0.5, 0.5, 0.5, 0.5]);
 
-        // Check prods (col-major): [0.5, 3.0, 7.5, 14.0]
         assert_eq!(prod.data(), &[0.5, 3.0, 7.5, 14.0]);
 
         // Check divs (col-major): [2.0, 1.333..., 1.2, 1.14...]
-        // Using element access for more specific checks on floating point results
         assert_eq!(div.rows(), 2);
         assert_eq!(div.cols(), 2);
         assert!((div[(0, 0)] - 1.0 / 0.5).abs() < 1e-9); // 2.0
@@ -1785,20 +1697,18 @@ mod tests {
         // Perform the swap directly on the matrix
         matrix.swap_columns(0, 2); // Swap column 0 and column 2
 
-        // --- Assertions ---
+        // Verify the dimensions are unchanged
-
-        // 1. Verify the dimensions are unchanged
         assert_eq!(matrix.rows(), 3, "Matrix rows should remain unchanged");
         assert_eq!(matrix.cols(), 3, "Matrix cols should remain unchanged");
 
-        // 2. Verify the column that was NOT swapped is unchanged
+        // Verify the column that was NOT swapped is unchanged
         assert_eq!(
             matrix.column(1),
             initial_col1_data.as_slice(), // Comparing slice to slice
             "Column 1 data should be unchanged"
         );
 
-        // 3. Verify the data swap occurred correctly using the COLUMN ACCESSOR
+        // Verify the data swap occurred correctly using the COLUMN ACCESSOR
         // The data originally at index 0 should now be at index 2
         assert_eq!(
             matrix.column(2),
@@ -1812,16 +1722,14 @@ mod tests {
             "Column 0 should now contain the original data from column 2"
         );
 
-        // 4. (Optional but useful) Verify the underlying raw data vector
+        // Verify the underlying raw data vector
-        // Original data: [1, 2, 3, 4, 5, 6, 7, 8, 9]
-        // Expected data after swapping col 0 and col 2: [7, 8, 9, 4, 5, 6, 1, 2, 3]
         assert_eq!(
             matrix.data(),
             &[7, 8, 9, 4, 5, 6, 1, 2, 3],
             "Underlying data vector is incorrect after swap"
         );
 
-        // 5. Test swapping with self (should be a no-op)
+        // Test swapping with self (should be a no-op)
         let state_before_self_swap = matrix.clone();
         matrix.swap_columns(1, 1);
         assert_eq!(
@@ -1829,7 +1737,7 @@ mod tests {
             "Swapping a column with itself should not change the matrix"
         );
 
-        // 6. Test swapping adjacent columns
+        // Test swapping adjacent columns
         let mut matrix2 = create_test_matrix_i32();
         let initial_col0_data_m2 = matrix2.column(0).to_vec();
         let initial_col1_data_m2 = matrix2.column(1).to_vec();

src/matrix/seriesops.rs

@@ -12,6 +12,9 @@ pub trait SeriesOps {
     where
         F: FnMut(&[f64]) -> U;
 
+    fn matrix_mul(&self, other: &Self) -> FloatMatrix;
+    fn dot(&self, other: &Self) -> FloatMatrix;
+
     fn sum_vertical(&self) -> Vec<f64>;
     fn sum_horizontal(&self) -> Vec<f64>;
 
@@ -139,11 +142,37 @@ impl SeriesOps for FloatMatrix {
         let data = self.data().iter().map(|v| v.is_nan()).collect();
         BoolMatrix::from_vec(data, self.rows(), self.cols())
     }
-}
 
+    fn matrix_mul(&self, other: &Self) -> FloatMatrix {
+        let (m, n) = (self.rows(), self.cols());
+        let (n2, p) = (other.rows(), other.cols());
+        assert_eq!(
+            n, n2,
+            "Cannot multiply: left is {}x{}, right is {}x{}",
+            m, n, n2, p
+        );
+
+        // Column-major addressing: element (row i, col j) lives at j * m + i
+        let mut data = vec![0.0; m * p];
+        for i in 0..m {
+            for j in 0..p {
+                let mut sum = 0.0;
+                for k in 0..n {
+                    sum += self[(i, k)] * other[(k, j)];
+                }
+                data[j * m + i] = sum; // <-- fixed index
+            }
+        }
+        FloatMatrix::from_vec(data, m, p)
+    }
+    fn dot(&self, other: &Self) -> FloatMatrix {
+        self.matrix_mul(other)
+    }
+}
 
 #[cfg(test)]
 mod tests {
+
     use super::*;
 
     // Helper function to create a FloatMatrix for SeriesOps testing
@@ -156,6 +185,22 @@ mod tests {
         FloatMatrix::from_vec(data, 3, 3)
     }
 
+    fn create_float_test_matrix_4x4() -> FloatMatrix {
+        // 4x4 matrix (column-major) with some NaNs
+        // 1.0  5.0  9.0  13.0
+        // 2.0  NaN  10.0 NaN
+        // 3.0  6.0  NaN  14.0
+        // NaN  7.0  11.0 NaN
+        // first make array with 16 elements
+        FloatMatrix::from_vec(
+            (0..16)
+                .map(|i| if i % 5 == 0 { f64::NAN } else { i as f64 })
+                .collect(),
+            4,
+            4,
+        )
+    }
+
     // --- Tests for SeriesOps (FloatMatrix) ---
 
     #[test]
@@ -256,6 +301,48 @@ mod tests {
         assert_eq!(matrix.is_nan(), expected_matrix);
     }
 
+    #[test]
+    fn test_series_ops_matrix_mul() {
+        let a = FloatMatrix::from_vec(vec![1.0, 2.0, 3.0, 4.0], 2, 2); // 2x2 matrix
+        let b = FloatMatrix::from_vec(vec![5.0, 6.0, 7.0, 8.0], 2, 2); // 2x2 matrix
+                                                                       // result should be: 23, 34, 31, 46
+        let expected = FloatMatrix::from_vec(vec![23.0, 34.0, 31.0, 46.0], 2, 2);
+        assert_eq!(a.matrix_mul(&b), expected);
+
+        assert_eq!(a.dot(&b), a.matrix_mul(&b)); // dot should be the same as matrix_mul for FloatMatrix
+    }
+    #[test]
+    fn test_series_ops_matrix_mul_with_nans() {
+        let a = create_float_test_matrix(); // 3x3 matrix with some NaNs
+        let b = create_float_test_matrix(); // 3x3 matrix with some NaNs
+
+        let mut result_vec = Vec::new();
+        result_vec.push(30.0);
+        for _ in 1..9 {
+            result_vec.push(f64::NAN);
+        }
+        let expected = FloatMatrix::from_vec(result_vec, 3, 3);
+
+        let result = a.matrix_mul(&b);
+
+        assert_eq!(result.is_nan(), expected.is_nan());
+        assert_eq!(
+            result.count_nan_horizontal(),
+            expected.count_nan_horizontal()
+        );
+        assert_eq!(result.count_nan_vertical(), expected.count_nan_vertical());
+        assert_eq!(result[(0, 0)], expected[(0, 0)]);
+    }
+
+    #[test]
+    #[should_panic(expected = "Cannot multiply: left is 3x3, right is 4x4")]
+    fn test_series_ops_matrix_mul_errors() {
+        let a = create_float_test_matrix();
+        let b = create_float_test_matrix_4x4();
+
+        a.dot(&b); // This should panic due to dimension mismatch
+    }
+
     // --- Edge Cases for SeriesOps ---
 
     #[test]
@@ -286,7 +373,7 @@ mod tests {
     #[test]
     fn test_series_ops_1xn_matrix() {
         let matrix = FloatMatrix::from_vec(vec![1.0, f64::NAN, 3.0, 4.0], 1, 4); // 1 row, 4 cols
-        // Data: [1.0, NaN, 3.0, 4.0]
+                                                                                 // Data: [1.0, NaN, 3.0, 4.0]
 
         // Vertical (sums/prods/counts per column - each col is just one element)
         assert_eq!(matrix.sum_vertical(), vec![1.0, 0.0, 3.0, 4.0]); // NaN sum is 0
@@ -316,7 +403,7 @@ mod tests {
     #[test]
     fn test_series_ops_nx1_matrix() {
         let matrix = FloatMatrix::from_vec(vec![1.0, 2.0, f64::NAN, 4.0], 4, 1); // 4 rows, 1 col
-        // Data: [1.0, 2.0, NaN, 4.0]
+                                                                                 // Data: [1.0, 2.0, NaN, 4.0]
 
         // Vertical (sums/prods/counts for the single column)
         // Col 0: 1.0 + 2.0 + NaN + 4.0 = 7.0