From 358ef7e19f9960abeb12b2dfe7120d429593fa24 Mon Sep 17 00:00:00 2001
From: Peli de Halleux <pelikhan@users.noreply.github.com>
Date: Mon, 8 Jan 2018 23:05:09 -0800
Subject: [PATCH] started on matrix library

---
 libs/matrix/README.md |   1 +
 libs/matrix/matrix.ts | 140 ++++++++++++++++++++++++++++++++++++++++++
 libs/matrix/pxt.json  |  15 +++++
 libs/matrix/test.ts   |   1 +
 pxtarget.json         |   3 +-
 5 files changed, 159 insertions(+), 1 deletion(-)
 create mode 100644 libs/matrix/README.md
 create mode 100644 libs/matrix/matrix.ts
 create mode 100644 libs/matrix/pxt.json
 create mode 100644 libs/matrix/test.ts

diff --git a/libs/matrix/README.md b/libs/matrix/README.md
new file mode 100644
index 00000000..f417dac9
--- /dev/null
+++ b/libs/matrix/README.md
@@ -0,0 +1 @@
+# Matrix
diff --git a/libs/matrix/matrix.ts b/libs/matrix/matrix.ts
new file mode 100644
index 00000000..64a578f6
--- /dev/null
+++ b/libs/matrix/matrix.ts
@@ -0,0 +1,140 @@
+namespace matrix {
+    function pre(check: boolean) {
+        if (!check)
+            control.reset();
+    }
+
+    /**
+     * A 2D matrix
+     */
+    export class Matrix {
+        private _rows: number;
+        private _cols: number;
+        private _values: number[];
+
+        constructor(rows: number, cols: number, values: number[] = []) {
+            pre(rows > 0);
+            pre(cols > 0);
+            this._rows = rows;
+            this._cols = cols;
+            this._values = values || [];
+            const n = this._rows * this._cols;
+            // fill gaps
+            while (this._values.length < n)
+                this._values.push(0);
+        }
+
+        /**
+         * Creates an identity matrix
+         * @param size 
+         */
+        static identity(size: number): Matrix {
+            const m = new Matrix(size, size);
+            for (let i = 0; i < size; ++i)
+                m._values[i * size] = 1;
+            return m;
+        }
+
+        /**
+         * Sets a value in the array
+         * @param row 
+         * @param col 
+         * @param val 
+         */
+        set(row: number, col: number, val: number) {
+            pre(row == row >> 0 && row >= 0 && row < this._rows && col == col >> 0 && col >= 0 && col < this._cols);
+            this._values[row * this._cols + col] = val;
+        }
+
+        /**
+         * Gets a value from the matrix
+         * @param row 
+         * @param col 
+         */
+        get(row: number, col: number): number {
+            pre(row == row >> 0 && row >= 0 && row < this._rows && col == col >> 0 && col >= 0 && col < this._cols);
+            return this._values[row * this._cols + col];
+        }
+
+        /**
+         * Gets the number of rows
+         */
+        get rows(): number {
+            return this._rows;
+        }
+
+        /**
+         * Gets the number of colums
+         */
+        get cols(): number {
+            return this._cols;
+        }
+
+        /**
+         * Gets the raw storage buffer
+         */
+        get values(): number[] {
+            return this._values;
+        }
+
+        /**
+         * Returns a new matrix as the sum of both matrices
+         * @param other 
+         */
+        add(other: Matrix): Matrix {
+            pre(this._rows != other._rows || this._cols != other._cols)
+            const n = this._rows * this._cols;
+            const r: number[] = [];
+            for (let i = 0; i < n; ++i) {
+                r[i] = this._values[i] + other._values[i];
+            }
+            return new Matrix(this._rows, this._cols, r);
+        }
+
+        /**
+         * Returns a new matrix with scaled values
+         * @param factor 
+         */
+        scale(factor: number): Matrix {
+            const n = this._rows * this._cols;
+            const r: number[] = [];
+            for (let i = 0; i < n; ++i) {
+                r[i] = this._values[i] * factor;
+            }
+            return new Matrix(this._rows, this._cols, r);
+        }
+
+        /**
+         * Multiplies the current matrix with the other matrix and returns a new matrix
+         * @param other 
+         */
+        multiply(other: Matrix): Matrix {
+            pre(this._cols == other._rows);
+            const r: number[] = [];
+            for (let i = 0; i < this._rows; ++i) {
+                for (let j = 0; j < other._cols; ++j) {
+                    let s = 0;
+                    for (let k = 0; k < this._cols; ++k) {
+                        s += this._values[i * this._cols + k] * other._values[k * other._cols + j];
+                    }
+                    r[i * other._cols + j];
+                }
+            }
+            return new Matrix(this._rows, other._cols, r);
+        }
+
+        /**
+         * Returns a transposed matrix
+         */
+        transpose(): Matrix {
+            const R = new Matrix(this._cols, this._rows);
+            const r: number[] = R._values;
+            for(let i = 0; i < this._rows; ++i) {
+                for(let j = 0; j < this._cols; ++j) {
+                    r[i + j * this._rows] = this._values[i * this._cols + j];
+                }
+            }
+            return R;
+        }
+    }
+}
\ No newline at end of file
diff --git a/libs/matrix/pxt.json b/libs/matrix/pxt.json
new file mode 100644
index 00000000..23ecdbb6
--- /dev/null
+++ b/libs/matrix/pxt.json
@@ -0,0 +1,15 @@
+{
+    "name": "matrix",
+    "description": "Matrix algebra",
+    "files": [
+        "README.md",
+        "matrix.ts"
+    ],
+    "testFiles": [
+        "test.ts"
+    ],
+    "public": true,
+    "dependencies": {
+            "core": "file:../core"
+    }
+}
\ No newline at end of file
diff --git a/libs/matrix/test.ts b/libs/matrix/test.ts
new file mode 100644
index 00000000..cd7d7e93
--- /dev/null
+++ b/libs/matrix/test.ts
@@ -0,0 +1 @@
+// add tests here
diff --git a/pxtarget.json b/pxtarget.json
index c2914edd..fd6b2b14 100644
--- a/pxtarget.json
+++ b/pxtarget.json
@@ -18,7 +18,8 @@
         "libs/chassis",
         "libs/ev3",
         "libs/tests",
-        "libs/behaviors"
+        "libs/behaviors",
+        "libs/matrix"
     ],
     "simulator": {
         "autoRun": true,