From 9a743bba41cba857f943db1111cc552c7a730ca4 Mon Sep 17 00:00:00 2001
From: Arjun Patrawala <ajpat1234@gmail.com>
Date: Sun, 1 Jul 2018 23:56:16 -0700
Subject: [PATCH 1/2] minor edits + a beautiful print method

-refactored errors to JavaScript convention
-created a beautiful print method (try it in Google Chrome)
-cut down if statements and for statements where brackets weren't needed
---
 lib/matrix.js | 82 ++++++++++++++++++++++++++-------------------------
 1 file changed, 42 insertions(+), 40 deletions(-)

diff --git a/lib/matrix.js b/lib/matrix.js
index b232d36..98bec41 100644
--- a/lib/matrix.js
+++ b/lib/matrix.js
@@ -10,11 +10,9 @@ class Matrix {
 
   copy() {
     let m = new Matrix(this.rows, this.cols);
-    for (let i = 0; i < this.rows; i++) {
-      for (let j = 0; j < this.cols; j++) {
+    for (let i = 0; i < this.rows; i++)
+      for (let j = 0; j < this.cols; j++)
         m.data[i][j] = this.data[i][j];
-      }
-    }
     return m;
   }
 
@@ -23,10 +21,8 @@ class Matrix {
   }
 
   static subtract(a, b) {
-    if (a.rows !== b.rows || a.cols !== b.cols) {
-      console.log('Columns and Rows of A must match Columns and Rows of B.');
-      return;
-    }
+    if (a.rows !== b.rows || a.cols !== b.cols)
+      throw new TypeError('Matrix dimensions do not match');
 
     // Return a new Matrix a-b
     return new Matrix(a.rows, a.cols)
@@ -35,11 +31,9 @@ class Matrix {
 
   toArray() {
     let arr = [];
-    for (let i = 0; i < this.rows; i++) {
-      for (let j = 0; j < this.cols; j++) {
+    for (let i = 0; i < this.rows; i++)
+      for (let j = 0; j < this.cols; j++)
         arr.push(this.data[i][j]);
-      }
-    }
     return arr;
   }
 
@@ -49,14 +43,13 @@ class Matrix {
 
   add(n) {
     if (n instanceof Matrix) {
-      if (this.rows !== n.rows || this.cols !== n.cols) {
-        console.log('Columns and Rows of A must match Columns and Rows of B.');
-        return;
-      }
+      if (this.rows !== n.rows || this.cols !== n.cols)
+        throw new TypeError('Matrix dimensions do not match');
+      
       return this.map((e, i, j) => e + n.data[i][j]);
-    } else {
+    } else
       return this.map(e => e + n);
-    }
+    
   }
 
   static transpose(matrix) {
@@ -66,45 +59,36 @@ class Matrix {
 
   static multiply(a, b) {
     // Matrix product
-    if (a.cols !== b.rows) {
-      console.log('Columns of A must match rows of B.');
-      return;
-    }
+    if (a.cols !== b.rows)
+      throw new TypeError('Matrix `a` columns do not match matrix `b` rows');
 
     return new Matrix(a.rows, b.cols)
       .map((e, i, j) => {
         // Dot product of values in col
         let sum = 0;
-        for (let k = 0; k < a.cols; k++) {
-          sum += a.data[i][k] * b.data[k][j];
-        }
+        for (let k = 0; k < a.cols; k++) sum += a.data[i][k] * b.data[k][j];
         return sum;
       });
   }
 
   multiply(n) {
     if (n instanceof Matrix) {
-      if (this.rows !== n.rows || this.cols !== n.cols) {
-        console.log('Columns and Rows of A must match Columns and Rows of B.');
-        return;
-      }
+      if (this.rows !== n.rows || this.cols !== n.cols)
+        throw new TypeError('Matrix dimensions must match');
 
       // hadamard product
       return this.map((e, i, j) => e * n.data[i][j]);
-    } else {
-      // Scalar product
+    } else // Scalar product
       return this.map(e => e * n);
-    }
   }
 
   map(func) {
     // Apply a function to every element of matrix
-    for (let i = 0; i < this.rows; i++) {
+    for (let i = 0; i < this.rows; i++)
       for (let j = 0; j < this.cols; j++) {
         let val = this.data[i][j];
         this.data[i][j] = func(val, i, j);
       }
-    }
     return this;
   }
 
@@ -114,8 +98,27 @@ class Matrix {
       .map((e, i, j) => func(matrix.data[i][j], i, j));
   }
 
-  print() {
-    console.table(this.data);
+   print(decimalPoints) {
+    if (!decimalPoints)
+      decimalPoints = 3;
+    
+    let text = '';
+    for (let i = 0; i < this.rows; i++) {
+      for (let j = 0; j < this.cols; j++) {
+        if (j !== 0) text += ' ';
+        if (this.data[i][j] > 0) text += ' ';
+        
+        text += this.data[i][j].toFixed(decimalPoints);
+        
+        if (j !== this.cols - 1) text += ' ';
+      }
+      text += '\n';
+    }
+    if (typeof window.chrome === 'object')
+      console.log('%c' + text, 'font-size: 12px; border-left: 1px solid black; border-right: 1px solid black; padding: 4px 8px; color: #333333; margin: 5px;');
+    else
+      console.log(text);
+    
     return this;
   }
 
@@ -124,15 +127,14 @@ class Matrix {
   }
 
   static deserialize(data) {
-    if (typeof data == 'string') {
+    if (typeof data === 'string')
       data = JSON.parse(data);
-    }
+      
     let matrix = new Matrix(data.rows, data.cols);
     matrix.data = data.data;
     return matrix;
   }
 }
 
-if (typeof module !== 'undefined') {
+if (typeof module !== 'undefined')
   module.exports = Matrix;
-}

From cc81e9bc469498a54e39ebe73eedd216a5191054 Mon Sep 17 00:00:00 2001
From: Arjun Patrawala <ajpat1234@gmail.com>
Date: Sat, 7 Jul 2018 21:28:26 -0700
Subject: [PATCH 2/2] update to es6

---
 lib/matrix.js | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/lib/matrix.js b/lib/matrix.js
index 98bec41..28790d1 100644
--- a/lib/matrix.js
+++ b/lib/matrix.js
@@ -98,9 +98,7 @@ class Matrix {
       .map((e, i, j) => func(matrix.data[i][j], i, j));
   }
 
-   print(decimalPoints) {
-    if (!decimalPoints)
-      decimalPoints = 3;
+   print(decimalPoints = 3) {
     
     let text = '';
     for (let i = 0; i < this.rows; i++) {