added GridGetX and GridGetY

Maths/GridGet.js

@@ -0,0 +1,56 @@
+/*
+    author: TangibleDream
+    license: GPL-3.0 or later
+
+    These methods will find x or y given the element and columns for a 2 dimensional array.
+
+    If your array is a perfect square, you can find columns by getting the square
+    root of the length of the array.
+
+    Let's say for instance you had an array of 10 by 10 or 100, elements and you wanted to
+    find the shortest distance between element 3, and element 49. In this case coding out
+    a function to return the distance without finding x and y for both elements I found to
+    be painful. If you first find x and y, where 3 becomes 4,1 and 49 becomes 10,5, you can
+    find distance by first subtracting x from x and y from y this returns 6,4 or -6,-4.
+    Next apply absolute value to assure the results are positive,
+    last choose the maximum value of the set, or 6.
+
+    +--+--+--+--+--+--+--+--+--+--+
+    |  |  |  | 3|  |  |  |  |  |  |
+    +--+--+--+--+--+--+--+--+--+--+
+    |  |  |  |  |  |  |  |  |  |  |
+    +--+--+--+--+--+--+--+--+--+--+
+    |  |  |  |  |  |  |  |  |  |  |
+    +--+--+--+--+--+--+--+--+--+--+
+    |  |  |  |  |  |  |  |  |  |49|
+    +--+--+--+--+--+--+--+--+--+--+
+    |  |  |  |  |  |  |  |  |  |  |
+
+    +--+--+--+--+--+--+--+--+--+--+
+    |  |  |  | 3|  |  |  |  |  |  |
+    +--+--+--+--+--+--+--+--+--+--+
+    |  |  |  |  | 1|  |  |  |  |  |
+    +--+--+--+--+--+--+--+--+--+--+
+    |  |  |  |  |  | 2|  |  |  |  |
+    +--+--+--+--+--+--+--+--+--+--+
+    |  |  |  |  |  |  | 3| 4| 5|6!|
+    +--+--+--+--+--+--+--+--+--+--+
+    |  |  |  |  |  |  |  |  |  |  |
+
+*/
+
+const gridGetX = (columns, index) => {
+  while ((index + 1) > columns) {
+    index = index - columns
+  }
+  return (index + 1)
+}
+
+const gridGetY = (columns, index) => {
+  return (Math.floor(index / columns)) + 1
+}
+
+console.log(`If a square array has 400 elements,  then the value of x for the 27th element is ${gridGetX(Math.sqrt(400), 27)}`)
+console.log(`If an array has 7 columns and 3 rows,  then the value of x for the 11th element is ${gridGetX(7, 11)}`)
+console.log(`If a square array has 400 elements,  then the value of y for the 27th element is ${gridGetY(Math.sqrt(400), 27)}`)
+console.log(`If an array has 7 columns and 3 rows,  then the value of y for the 11th element is ${gridGetY(7, 11)}`)