start of math operations

src/core/operations/Arithmetic.js

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+import Utils from "../Utils.js";
+
+/**
+ * Math operations on numbers.
+ *
+ * @author bwhitn [brian.m.whitney@outlook.com]
+ * @copyright Crown Copyright 2016
+ * @license Apache-2.0
+ *
+ * @namespace
+ */
+const Arithmetic = {
+
+    /**
+     * @constant
+     * @default
+     */
+    DELIM_OPTIONS: ["Space", "Comma", "Semi-colon", "Colon", "Line feed", "CRLF"],
+
+    /**
+     * @constant
+     * @default
+     */
+    OPERATIONS: ["Sum", "Sub", "Multiply", "Divide", "Mean", "Median", "Mode"],
+
+    /**
+     * A mapping of operation names to their function.
+     * @constant
+     */
+     opMap: {
+         "Sub":         _sub,
+         "Sum":         _sum,
+         "Multiply":    _multiply,
+         "Divide":      _divide,
+         "Mean":        _mean,
+         "Median":      _median,
+         "Mode":        _mode,
+     },
+
+    /**
+     *
+     *
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    runOp: function(input, args) {
+        const delim = Utils.charRep[args[0] || "Space"];
+        let splitNumbers = input.split(delim),
+            numbers = [],
+            num,
+            retVal;
+        for (i = 0; i < splitNumbers.length; i++) {
+            if splitNumbers[i].indexOf(".") {
+                num = parseFloat(splitNumbers[i].trim());
+            } else {
+                num = parseInt(splitNumbers[i].trim());
+            }
+            if (num !== "NaN") {
+                numbers.append(num);
+            }
+        }
+        num = Arithmetic.opMap[args[1] || "Sum"](numbers);
+        if (num !== null) {
+            return "The values " + args[1] + "equal: " + num;
+        }
+        throw "Error with Arithmetic Operation: " + args[1];
+    },
+
+
+    _sum: function(data) {
+        let total = 0;
+        for (i = 0; i < data.length; i++) {
+            total += data[i];
+        }
+        return total;
+    },
+
+    _sub: function(data) {
+        let total = 0;
+        if (data.length > 1) {
+            total = data[0];
+            for (i = 1; i < data.length; i++) {
+                total -= data[i];
+            }
+        } else {
+            total = null;
+        }
+        return total;
+    },
+
+    _multiply: function(data) {
+        let total = 0;
+        if (data.length > 1) {
+            total = data[0];
+            for (i = 1; i < data.length; i++) {
+                total *= data[i];
+            }
+        } else {
+            total = null;
+        }
+        return total;
+    },
+
+    _divide: function(data) {
+        let total = 0;
+        if (data.length > 1) {
+            total = data[0];
+            for (i = 1; i < data.length; i++) {
+                total /= data[i]
+            }
+        } else {
+            total = null;
+        }
+        return total;
+    },
+
+    _mean: function(data) {
+        let total = 0;
+        if (data.length > 1) {
+            total = Arithmetic._sum(data) / data.length;
+        } else {
+            total = null;
+        }
+        return total;
+    },
+
+};
+
+export default Arithmetic;