fix: In trueWind.js derived values are now set to null in case that t…

…he input is null.

In trueWind.js derived values are now set to null in case that the input is null. Before a AWS of null resulted in a TWS of 0.

calcs/trueWind.js

@@ -10,23 +10,33 @@ module.exports = function (app) {
       'environment.wind.angleApparent'
     ],
     calculator: function (headTrue, speed, aws, awa) {
-      var apparentX = Math.cos(awa) * aws
-      var apparentY = Math.sin(awa) * aws
-      var angle = Math.atan2(apparentY, -speed + apparentX)
-      var speed = Math.sqrt(
-        Math.pow(apparentY, 2) + Math.pow(-speed + apparentX, 2)
-      )
+      var angle
+      var speed
+      var dir
 
-      if (aws < 1e-9) {
-        angle = awa
-      }
+      if (headTrue == null || speed == null || aws == null || awa == null) {
+        angle = null
+        speed = null
+        dir   = null
+      } else {
+        var apparentX = Math.cos(awa) * aws
+        var apparentY = Math.sin(awa) * aws
+        angle = Math.atan2(apparentY, -speed + apparentX)
+        speed = Math.sqrt(
+          Math.pow(apparentY, 2) + Math.pow(-speed + apparentX, 2)
+        )
+
+        if (aws < 1e-9) {
+          angle = awa
+        }
 
-      var dir = headTrue + angle
+        dir = headTrue + angle
 
-      if (dir > Math.PI * 2) {
-        dir = dir - Math.PI * 2
-      } else if (dir < 0) {
-        dir = dir + Math.PI * 2
+        if (dir > Math.PI * 2) {
+          dir = dir - Math.PI * 2
+        } else if (dir < 0) {
+          dir = dir + Math.PI * 2
+        }
       }
 
       return [