├── MagDec
    ├── css
    │   └── MagDec.css
    ├── templates
    │   └── MagDec.html
    └── WMM.html
├── LICENSE
├── README.md
└── MagDec.js


/MagDec/css/MagDec.css:
--------------------------------------------------------------------------------
 1 | 
 2 | .magDecWidget {
 3 |     white-space: nowrap;
 4 |     min-width: 310px;
 5 | }
 6 | 
 7 | .magDecWidget .valuesDiv {
 8 |     font-weight: normal;
 9 | }
10 | 
11 | .magDecWidget .attribute {
12 |     display: inline-block;
13 |     width: 130px;
14 |     height: 15px;
15 |     font-weight: bold;
16 | }
17 | 
18 | .magDecWidget .value {
19 |     font-weight: normal;
20 | }
21 | 
22 | .magDecWidget .warning {
23 |     color: red;
24 |     font-weight: bold;
25 | }
26 | .magDecWidget .smallText {
27 |     color: black;
28 |     font-weight: normal;
29 |     font-size: 7px;
30 | }
31 | 


--------------------------------------------------------------------------------
/LICENSE:
--------------------------------------------------------------------------------
 1 | The MIT License (MIT)
 2 | 
 3 | Copyright (c) 2016 
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining a copy
 6 | of this software and associated documentation files (the "Software"), to deal
 7 | in the Software without restriction, including without limitation the rights
 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 | 
12 | The above copyright notice and this permission notice shall be included in all
13 | copies or substantial portions of the Software.
14 | 
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 | SOFTWARE.
22 | 


--------------------------------------------------------------------------------
/MagDec/templates/MagDec.html:
--------------------------------------------------------------------------------
 1 | <div class="${theme}" role="presentation">
 2 |     
 3 |     <link rel="stylesheet" href="${css_path}"/>
 4 |     <div class="${css.valuesDiv}">
 5 |         <span class="${css.attribute}">Latitude: </span><span data-dojo-attach-point="MagDecLatitude" class="${css.value}"></span><br/>
 6 |         <span class="${css.attribute}">Longitude: </span><span data-dojo-attach-point="MagDecLongitude"></span><br/>
 7 |         <br/>
 8 |         <span class="${css.attribute}">Date: </span><span data-dojo-attach-point="MagDecDate"></span><br/>
 9 |         <br/>
10 |         <span class="${css.attribute}">Declination: </span><span data-dojo-attach-point="MagDecDeclination"></span><br/>
11 |         <span class="${css.attribute}">Horizontal Intensity: </span><span data-dojo-attach-point="MagDecHorizontalIntensity"></span><br/>
12 |         <span data-dojo-attach-point="Warning" class="${css.warning}"><br/><br/><br/></span><br/>
13 |         <span class="${css.smallText}">Datum: WGS84<br/>
14 |             Additional information on magnetic declination: <a href="http://geomag.nrcan.gc.ca/mag_fld/magdec-en.php" target="_blank">click here</a><br/>
15 |             Additional information on the World Magnetic Model 2015: <a href="https://www.ngdc.noaa.gov/geomag/WMM/" target="_blank">click here</a>
16 |         </span>
17 |     </div>
18 | </div>


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
  1 | # MagneticDeclination-Widget
  2 | 
  3 | ## Features
  4 | An ArcGIS for JavaScript API widget for calculating magnetic declination.
  5 | 
  6 | Model: World Magnetic Model 2015 (WMM-2015)  Current until December 2019.
  7 | Datum: WGS84
  8 | 
  9 | Press spacebar to pause/resume updating.
 10 | 
 11 | [View it live](http://joerogan.ca/maps/joegis/)
 12 | 
 13 | ## Helpful Links
 14 | * [Magnetic Declination](http://geomag.nrcan.gc.ca/mag_fld/magdec-en.php)
 15 | * [World Magnetic Model](https://www.ngdc.noaa.gov/geomag/WMM/)
 16 | 
 17 | ## Quickstart
 18 | ```javascript
 19 | on(mainMap, "load", function() {
 20 |     var magDec = new MagDec({
 21 |         map: mainMap
 22 |         }, "MagDecWindow");
 23 |     magDec.startup();
 24 | });
 25 | ```
 26 | 
 27 | ## Requirements
 28 | * Notepad or HTML editor
 29 | * A little background with JavaScript
 30 | * Experience with the [ArcGIS API for JavaScript](https://developers.arcgis.com/javascript/) would help.
 31 | 
 32 | ## Setup
 33 | Set your dojo config to load the module.
 34 | 
 35 | ```javascript
 36 | var package_path = window.location.pathname.substring(0, window.location.pathname.lastIndexOf('/'));
 37 | var dojoConfig = {
 38 |     // The locationPath logic below may look confusing but all its doing is
 39 |     // enabling us to load the api from a CDN and load local modules from the correct location.
 40 |     packages: [{
 41 |         name: "application",
 42 |         location: package_path + '/js'
 43 |     }]
 44 | };
 45 | ```
 46 | 
 47 | ## Require module
 48 | Include the module for the MagDec widget.
 49 | 
 50 | ```javascript
 51 | require(["application/MagDec", ... ], function(MagDec, ... ){ ... });
 52 | ```
 53 | 
 54 | ## Constructor
 55 | MagDec(options, srcNode);
 56 | 
 57 | ### Options (Object)
 58 | |property|required|type|value|description|
 59 | |---|---|---|---|---|
 60 | |map|x|Map|null|ArcGIS JS Map.|
 61 | |theme||string|magDecWidget|CSS Class for uniquely styling the widget.|
 62 | 
 63 | ## Methods
 64 | ### startup
 65 | startup(): Start the widget.  Map object must be loaded first.
 66 | 
 67 | ## Issues
 68 | Find a bug or want to request a new feature?  Please let us know by submitting an issue.
 69 | 
 70 | ## Contributing
 71 | Anyone and everyone is welcome to contribute.
 72 | 
 73 | ## Credits
 74 | Modified from code create by Christopher Weiss (cmweiss@gmail.com) Copyright 2012
 75 | Adapted from the geomagc software and World Magnetic Model of the NOAA
 76 | Satellite and Information Service, National Geophysical Data Center
 77 | [Source](http://www.ngdc.noaa.gov/geomag/WMM/DoDWMM.shtml)
 78 | 
 79 | ## Licensing
 80 | The MIT License (MIT)
 81 | 
 82 | Copyright (c) 2016 Joseph Rogan
 83 | 
 84 | Permission is hereby granted, free of charge, to any person obtaining a copy
 85 | of this software and associated documentation files (the "Software"), to deal
 86 | in the Software without restriction, including without limitation the rights
 87 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 88 | copies of the Software, and to permit persons to whom the Software is
 89 | furnished to do so, subject to the following conditions:
 90 | 
 91 | The above copyright notice and this permission notice shall be included in all
 92 | copies or substantial portions of the Software.
 93 | 
 94 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 95 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 96 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 97 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 98 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 99 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
100 | SOFTWARE.
101 | 
102 | 


--------------------------------------------------------------------------------
/MagDec/WMM.html:
--------------------------------------------------------------------------------
 1 |     2015.0            WMM-2015        12/15/2014
 2 |   1  0  -29438.5       0.0       10.7        0.0
 3 |   1  1   -1501.1    4796.2       17.9      -26.8
 4 |   2  0   -2445.3       0.0       -8.6        0.0
 5 |   2  1    3012.5   -2845.6       -3.3      -27.1
 6 |   2  2    1676.6    -642.0        2.4      -13.3
 7 |   3  0    1351.1       0.0        3.1        0.0
 8 |   3  1   -2352.3    -115.3       -6.2        8.4
 9 |   3  2    1225.6     245.0       -0.4       -0.4
10 |   3  3     581.9    -538.3      -10.4        2.3
11 |   4  0     907.2       0.0       -0.4        0.0
12 |   4  1     813.7     283.4        0.8       -0.6
13 |   4  2     120.3    -188.6       -9.2        5.3
14 |   4  3    -335.0     180.9        4.0        3.0
15 |   4  4      70.3    -329.5       -4.2       -5.3
16 |   5  0    -232.6       0.0       -0.2        0.0
17 |   5  1     360.1      47.4        0.1        0.4
18 |   5  2     192.4     196.9       -1.4        1.6
19 |   5  3    -141.0    -119.4        0.0       -1.1
20 |   5  4    -157.4      16.1        1.3        3.3
21 |   5  5       4.3     100.1        3.8        0.1
22 |   6  0      69.5       0.0       -0.5        0.0
23 |   6  1      67.4     -20.7       -0.2        0.0
24 |   6  2      72.8      33.2       -0.6       -2.2
25 |   6  3    -129.8      58.8        2.4       -0.7
26 |   6  4     -29.0     -66.5       -1.1        0.1
27 |   6  5      13.2       7.3        0.3        1.0
28 |   6  6     -70.9      62.5        1.5        1.3
29 |   7  0      81.6       0.0        0.2        0.0
30 |   7  1     -76.1     -54.1       -0.2        0.7
31 |   7  2      -6.8     -19.4       -0.4        0.5
32 |   7  3      51.9       5.6        1.3       -0.2
33 |   7  4      15.0      24.4        0.2       -0.1
34 |   7  5       9.3       3.3       -0.4       -0.7
35 |   7  6      -2.8     -27.5       -0.9        0.1
36 |   7  7       6.7      -2.3        0.3        0.1
37 |   8  0      24.0       0.0        0.0        0.0
38 |   8  1       8.6      10.2        0.1       -0.3
39 |   8  2     -16.9     -18.1       -0.5        0.3
40 |   8  3      -3.2      13.2        0.5        0.3
41 |   8  4     -20.6     -14.6       -0.2        0.6
42 |   8  5      13.3      16.2        0.4       -0.1
43 |   8  6      11.7       5.7        0.2       -0.2
44 |   8  7     -16.0      -9.1       -0.4        0.3
45 |   8  8      -2.0       2.2        0.3        0.0
46 |   9  0       5.4       0.0        0.0        0.0
47 |   9  1       8.8     -21.6       -0.1       -0.2
48 |   9  2       3.1      10.8       -0.1       -0.1
49 |   9  3      -3.1      11.7        0.4       -0.2
50 |   9  4       0.6      -6.8       -0.5        0.1
51 |   9  5     -13.3      -6.9       -0.2        0.1
52 |   9  6      -0.1       7.8        0.1        0.0
53 |   9  7       8.7       1.0        0.0       -0.2
54 |   9  8      -9.1      -3.9       -0.2        0.4
55 |   9  9     -10.5       8.5       -0.1        0.3
56 |  10  0      -1.9       0.0        0.0        0.0
57 |  10  1      -6.5       3.3        0.0        0.1
58 |  10  2       0.2      -0.3       -0.1       -0.1
59 |  10  3       0.6       4.6        0.3        0.0
60 |  10  4      -0.6       4.4       -0.1        0.0
61 |  10  5       1.7      -7.9       -0.1       -0.2
62 |  10  6      -0.7      -0.6       -0.1        0.1
63 |  10  7       2.1      -4.1        0.0       -0.1
64 |  10  8       2.3      -2.8       -0.2       -0.2
65 |  10  9      -1.8      -1.1       -0.1        0.1
66 |  10 10      -3.6      -8.7       -0.2       -0.1
67 |  11  0       3.1       0.0        0.0        0.0
68 |  11  1      -1.5      -0.1        0.0        0.0
69 |  11  2      -2.3       2.1       -0.1        0.1
70 |  11  3       2.1      -0.7        0.1        0.0
71 |  11  4      -0.9      -1.1        0.0        0.1
72 |  11  5       0.6       0.7        0.0        0.0
73 |  11  6      -0.7      -0.2        0.0        0.0
74 |  11  7       0.2      -2.1        0.0        0.1
75 |  11  8       1.7      -1.5        0.0        0.0
76 |  11  9      -0.2      -2.5        0.0       -0.1
77 |  11 10       0.4      -2.0       -0.1        0.0
78 |  11 11       3.5      -2.3       -0.1       -0.1
79 |  12  0      -2.0       0.0        0.1        0.0
80 |  12  1      -0.3      -1.0        0.0        0.0
81 |  12  2       0.4       0.5        0.0        0.0
82 |  12  3       1.3       1.8        0.1       -0.1
83 |  12  4      -0.9      -2.2       -0.1        0.0
84 |  12  5       0.9       0.3        0.0        0.0
85 |  12  6       0.1       0.7        0.1        0.0
86 |  12  7       0.5      -0.1        0.0        0.0
87 |  12  8      -0.4       0.3        0.0        0.0
88 |  12  9      -0.4       0.2        0.0        0.0
89 |  12 10       0.2      -0.9        0.0        0.0
90 |  12 11      -0.9      -0.2        0.0        0.0
91 |  12 12       0.0       0.7        0.0        0.0
92 | 999999999999999999999999999999999999999999999999
93 | 999999999999999999999999999999999999999999999999
94 | 


--------------------------------------------------------------------------------
/MagDec.js:
--------------------------------------------------------------------------------
  1 | /////////////////////////////////////////////////////////////////////////////////////
  2 | ///////////////////////////////--------MagDec.js-------//////////////////////////////
  3 | /////////////////////////////////////////////////////////////////////////////////////
  4 | // 
  5 | // Version: 1.2
  6 | // Author: Joseph Rogan (joseph.rogan@forces.gc.ca canadajebus@gmail.com)
  7 | // 
  8 | // Credits: Modified from code create by Christopher Weiss (cmweiss@gmail.com) Copyright 2012
  9 | // Adapted from the geomagc software and World Magnetic Model of the NOAA
 10 | // Satellite and Information Service, National Geophysical Data Center
 11 | // http://www.ngdc.noaa.gov/geomag/WMM/DoDWMM.shtml
 12 | // 
 13 | // This reusable widget allows the user to calculate magnetic declination at the point 
 14 | // of the mouse hover.
 15 | // 
 16 | // on(mainMap, "load", function() {
 17 | //        //MagDec widget Example
 18 | //        var magDec = new MagDec({
 19 | //            map: mainMap
 20 | //            }, "MagDecWindow");
 21 | //        magDec.startup();
 22 | //    });
 23 | //
 24 | // Changes:
 25 | // Version 1.2
 26 | //  -Minor tweak to size and warning text format.
 27 | // Version 1.1
 28 | //  -Added .magDecWidget { white-space: nowrap; min-width: 300px; } to css file
 29 | /////////////////////////////////////////////////////////////////////////////////////
 30 | /////////////////////////////////////////////////////////////////////////////////////
 31 | 
 32 | define([
 33 |     "dijit/_WidgetBase",
 34 |     "dijit/_TemplatedMixin",
 35 |     "dijit/_WidgetsInTemplateMixin", 
 36 |     
 37 |     "dojo/_base/declare",
 38 |     "dojo/_base/lang", 
 39 |     "dojo/on",
 40 |     "require",
 41 |     
 42 |     "esri/geometry/webMercatorUtils", 
 43 |     
 44 |     "dojo/text!./MagDec/WMM.html",
 45 |     
 46 |     "dojo/text!./MagDec/templates/MagDec.html",
 47 |     
 48 |     "dojo/domReady!"
 49 | 
 50 | ], function(_WidgetBase, _TemplatedMixin, _WidgetsInTemplateMixin, 
 51 |     declare, lang, on, require, 
 52 |     webMercatorUtils, 
 53 |     cof, 
 54 |     dijitTemplate)
 55 | {
 56 |     
 57 |     return declare([_WidgetBase, _TemplatedMixin, _WidgetsInTemplateMixin], {
 58 |         
 59 |         // Set the template .html file
 60 |         templateString: dijitTemplate,
 61 |         
 62 |         // Path to the templates .css file
 63 |         css_path: require.toUrl("./MagDec/css/MagDec.css"),
 64 |         
 65 |         // Vars
 66 |         cof: cof, 
 67 |         wmm: null, 
 68 |         
 69 |         maxord: null, 
 70 |         tc: null, 
 71 |         tc: null, 
 72 |         sp: null, 
 73 |         cp: null, 
 74 |         pp: null, 
 75 |         p: null, 
 76 |         dp: null, 
 77 |         a: null, 
 78 |         b: null, 
 79 |         re: null, 
 80 |         a2: null, 
 81 |         b2: null, 
 82 |         c2: null, 
 83 |         a4: null, 
 84 |         b4: null, 
 85 |         c4: null, 
 86 |         c: null, 
 87 |         cd: null, 
 88 |         k: null, 
 89 |         fn: null, 
 90 |         fm: null, 
 91 |         
 92 |         
 93 |         
 94 |         
 95 |         // The defaults
 96 |         defaults: {
 97 |             map: null, 
 98 |             theme: "magDecWidget",
 99 |             autoUpdate: true
100 |         },
101 |         
102 |         
103 |         // Called when the widget is declared as new object
104 |         constructor: function(options) {
105 |             // Mix in the given options with the defaults
106 |             var properties = lang.mixin({}, this.defaults, options);
107 |             this.set(properties);
108 |             
109 |             this.css = {
110 |                 valuesDiv: "valuesDiv",
111 |                 attribute: "attribute", 
112 |                 value: "value", 
113 |                 smallText: "smallText", 
114 |                 warning: "warning"
115 |             };
116 |             
117 |             
118 |         },
119 |         
120 |         
121 |         // Called after the widget is created
122 |         postCreate: function() {
123 |             this.inherited(arguments);
124 |             
125 |         },
126 |         
127 |         
128 |         // Called when the widget.startup() is used to view the widget
129 |         startup: function() {
130 |             this.inherited(arguments);
131 |             
132 |             // Calculate the model and initial math
133 |             this.wmm = this._cof2Obj(this.cof)
134 |             this._geoMagFactory(this.wmm);
135 |             
136 |             
137 |             // Wire events for the mouse move
138 |             var _this = this;
139 |             on(this.map, "mouse-move", function (evt, $_this) {
140 |                 if (_this.autoUpdate) _this._mapMoveCalc(evt, _this);
141 |                 });
142 |             on(this.map, "mouse-drag", function (evt, $_this) {
143 |                 if (_this.autoUpdate) _this._mapMoveCalc(evt, _this);
144 |                 });
145 |             
146 |             // Wire event for pausing updates with the keyboard
147 |             on(this.map, "key-down", function (evt, $_this) {
148 |                 if (evt.keyCode == 32)
149 |                 {
150 |                     if (_this.autoUpdate) _this.autoUpdate = false;
151 |                     else _this.autoUpdate = true;
152 |                 }
153 |                 });
154 |             
155 |             
156 |         },
157 |         
158 |         
159 |         
160 |         // Calculates geo mag on a map move event
161 |         _mapMoveCalc: function(evt, _this) {
162 |             
163 |             // Get the map coordinates in lat/lon
164 |             var mp = webMercatorUtils.webMercatorToGeographic(evt.mapPoint);
165 |             
166 |             // Get the inputs
167 |             var latitude = mp.y.toFixed(5);
168 |             var longitude = mp.x.toFixed(5);
169 |             var altitude = 0;
170 |             var time = new Date();
171 |             
172 |             // Calculate geo mag
173 |             var myGeoMag = _this.geoMag(latitude, longitude, altitude, time)
174 |             
175 |             // Calculate DMS values of the input lat lon
176 |             var lat = this.DD2DMS(mp.y);
177 |             var lon = this.DD2DMS(mp.x);
178 |             var dec = this.DD2DMS(myGeoMag.dec);
179 |             
180 |             // Update the html
181 |             _this.MagDecLatitude.innerHTML = latitude + " (" + lat.d + "&deg;" + lat.m + "'" + lat.s + "\" " + lat.hemiLat + ")";
182 |             _this.MagDecLongitude.innerHTML = longitude + " (" + lon.d + "&deg;" + lon.m + "'" + lon.s + "\" " + lon.hemiLon + ")";
183 |             
184 |             var months = ["January","February","March","April","May","June","July","August","September","October","November","December"];
185 |             _this.MagDecDate.innerHTML = time.getDate() + " " + months[time.getMonth()] + " " + time.getFullYear();
186 |             
187 |             _this.MagDecDeclination.innerHTML = Math.round(100*myGeoMag.dec)/100 + " (" + dec.d + "&deg;" + dec.m + "' " + dec.hemiLon + ")";
188 |             _this.MagDecHorizontalIntensity.innerHTML = Math.round(myGeoMag.bh) + " nT";
189 |             
190 |             // Warning message if required
191 |             if (myGeoMag.bh < 5000 & myGeoMag.bh > 1000)
192 |             {
193 |                 this.Warning.innerHTML = "Warning: The horizontal field strength at this<br/>location is only " + Math.round(myGeoMag.bh) + " nT (Compass readings<br/>have large uncertainties in areas where H is<br/>smaller than 5000 nT)"
194 |             }
195 |             else if (myGeoMag.bh < 1000)
196 |             {
197 |                 this.Warning.innerHTML = "Warning: The horizontal field strength at this<br/>location is only " + Math.round(myGeoMag.bh) + " nT (Compass readings<br/>have VERY LARGE uncertainties in areas where<br/>H is smaller than 1000 nT)"
198 |             }
199 |             else
200 |             {
201 |                 this.Warning.innerHTML = "<br/><span class='smallText'>Press <b>spacebar</b> to pause/resume updating.</span><br/><br/>";
202 |             }
203 |             
204 |             
205 |         },
206 |         
207 |         
208 |         // Calculates and returns DMS values from a Decimal Degree value
209 |         DD2DMS: function(value) {
210 |             
211 |             var Abs = Math.abs(value)
212 |             var D = Math.floor(Abs);
213 |             var M = Math.floor( ( Abs - D ) * 60 );
214 |             var S = Math.floor( ( Abs - D - (M/60)) * 60 * 60 );
215 |             var H1 = "North";
216 |             if (value<0) H1 = "South";
217 |             var H2 = "East";
218 |             if (value<0) H2 = "West";
219 |             
220 |             return {d: D, m: M, s: S, hemiLat: H1, hemiLon: H2}
221 |         }, 
222 |         
223 |         
224 |         // Calculates initial math on the model
225 |         _geoMagFactory: function(wmm) {
226 | 
227 |             var i, model, epoch = wmm.epoch,
228 |                 z = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
229 |             this.maxord = 12;
230 |                 
231 |             this.tc = [z.slice(), z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
232 |                 z.slice(), z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
233 |                 z.slice()];
234 |             this.sp = z.slice();
235 |             this.cp = z.slice();
236 |             this.pp = z.slice();
237 |             this.p = [z.slice(), z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
238 |                 z.slice(), z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
239 |                 z.slice()];
240 |             this.dp = [z.slice(), z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
241 |                 z.slice(), z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
242 |                 z.slice()];
243 |                 
244 |             this.a = 6378.137;
245 |             this.b = 6356.7523142;
246 |             this.re = 6371.2;
247 |             this.a2 = this.a * this.a;
248 |             this.b2 = this.b * this.b;
249 |             this.c2 = this.a2 - this.b2;
250 |             this.a4 = this.a2 * this.a2;
251 |             this.b4 = this.b2 * this.b2;
252 |             this.c4 = this.a4 - this.b4;
253 |             
254 |             this.c = [z.slice(), z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
255 |                     z.slice(), z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
256 |                     z.slice()];
257 |             this.cd = [z.slice(), z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
258 |                     z.slice(), z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
259 |                     z.slice()];
260 |                     
261 |             var n, m;
262 |             var snorm = [z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
263 |                     z.slice(), z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
264 |                     z.slice(), z.slice()];
265 |             var j;
266 |             this.k = [z.slice(), z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
267 |                     z.slice(), z.slice(), z.slice(), z.slice(), z.slice(), z.slice(),
268 |                     z.slice()];
269 |                     
270 |             var flnmj;
271 |                 
272 |             this.fn = [0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13];
273 |             this.fm = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];
274 |             
275 |             var D2;
276 | 
277 |             this.tc[0][0] = 0;
278 |             this.sp[0] = 0.0;
279 |             this.cp[0] = 1.0;
280 |             this.pp[0] = 1.0;
281 |             this.p[0][0] = 1;
282 |             
283 |             model = wmm.wmm;
284 |             for (i in model) {
285 |                 if (model.hasOwnProperty(i)) {
286 |                     if (model[i].m <= model[i].n) {
287 |                         this.c[model[i].m][model[i].n] = model[i].gnm;
288 |                         this.cd[model[i].m][model[i].n] = model[i].dgnm;
289 |                         if (model[i].m !== 0) {
290 |                             this.c[model[i].n][model[i].m - 1] = model[i].hnm;
291 |                             this.cd[model[i].n][model[i].m - 1] = model[i].dhnm;
292 |                         }
293 |                     }
294 |                 }
295 |             }
296 |             wmm = null;
297 |             model = null;
298 | 
299 |             /* CONVERT SCHMIDT NORMALIZED GAUSS COEFFICIENTS TO UNNORMALIZED */
300 |             snorm[0][0] = 1;
301 | 
302 |             for (n = 1; n <= this.maxord; n++) {
303 |                 snorm[0][n] = snorm[0][n - 1] * (2 * n - 1) / n;
304 |                 j = 2;
305 | 
306 |                 for (m = 0, D2 = (n - m + 1); D2 > 0; D2--, m++) {
307 |                     this.k[m][n] = (((n - 1) * (n - 1)) - (m * m)) /
308 |                         ((2 * n - 1) * (2 * n - 3));
309 |                     if (m > 0) {
310 |                         flnmj = ((n - m + 1) * j) / (n + m);
311 |                         snorm[m][n] = snorm[m - 1][n] * Math.sqrt(flnmj);
312 |                         j = 1;
313 |                         this.c[n][m - 1] = snorm[m][n] * this.c[n][m - 1];
314 |                         this.cd[n][m - 1] = snorm[m][n] * this.cd[n][m - 1];
315 |                     }
316 |                     this.c[m][n] = snorm[m][n] * this.c[m][n];
317 |                     this.cd[m][n] = snorm[m][n] * this.cd[m][n];
318 |                 }
319 |             }
320 |             this.k[1][1] = 0.0;
321 |         }, 
322 |         
323 |         
324 |         // Calculates geo mag properties
325 |         geoMag: function(glat, glon, h, date) {
326 |             
327 |             var alt = (h / 3280.8399) || 0, // convert h (in feet) to kilometers or set default of 0
328 |                 time = this._decimalDate(date),
329 |                 dt = time - this.wmm.epoch,
330 |                 rlat = this._deg2rad(glat),
331 |                 rlon = this._deg2rad(glon),
332 |                 srlon = Math.sin(rlon),
333 |                 srlat = Math.sin(rlat),
334 |                 crlon = Math.cos(rlon),
335 |                 crlat = Math.cos(rlat),
336 |                 srlat2 = srlat * srlat,
337 |                 crlat2 = crlat * crlat,
338 |                 q,
339 |                 q1,
340 |                 q2,
341 |                 ct,
342 |                 st,
343 |                 r2,
344 |                 r,
345 |                 d,
346 |                 ca,
347 |                 sa,
348 |                 aor,
349 |                 ar,
350 |                 br = 0.0,
351 |                 bt = 0.0,
352 |                 bp = 0.0,
353 |                 bpp = 0.0,
354 |                 par,
355 |                 temp1,
356 |                 temp2,
357 |                 parp,
358 |                 D4,
359 |                 bx,
360 |                 by,
361 |                 bz,
362 |                 bh,
363 |                 ti,
364 |                 dec,
365 |                 dip,
366 |                 gv;
367 |             this.sp[1] = srlon;
368 |             this.cp[1] = crlon;
369 |             
370 |             /* CONVERT FROM GEODETIC COORDS. TO SPHERICAL COORDS. */
371 |             q = Math.sqrt(this.a2 - this.c2 * srlat2);
372 |             q1 = alt * q;
373 |             q2 = ((q1 + this.a2) / (q1 + this.b2)) * ((q1 + this.a2) / (q1 + this.b2));
374 |             ct = srlat / Math.sqrt(q2 * crlat2 + srlat2);
375 |             st = Math.sqrt(1.0 - (ct * ct));
376 |             r2 = (alt * alt) + 2.0 * q1 + (this.a4 - this.c4 * srlat2) / (q * q);
377 |             r = Math.sqrt(r2);
378 |             d = Math.sqrt(this.a2 * crlat2 + this.b2 * srlat2);
379 |             ca = (alt + d) / r;
380 |             sa = this.c2 * crlat * srlat / (r * d);
381 |             
382 |             for (m = 2; m <= this.maxord; m++) {
383 |                 this.sp[m] = this.sp[1] * this.cp[m - 1] + this.cp[1] * this.sp[m - 1];
384 |                 this.cp[m] = this.cp[1] * this.cp[m - 1] - this.sp[1] * this.sp[m - 1];
385 |             }
386 |             
387 |             aor = this.re / r;
388 |             ar = aor * aor;
389 |             
390 |             for (n = 1; n <= this.maxord; n++) {
391 |                 ar = ar * aor;
392 |                 for (m = 0, D4 = (n + m + 1); D4 > 0; D4--, m++) {
393 |             
394 |             /*
395 |                     COMPUTE UNNORMALIZED ASSOCIATED LEGENDRE POLYNOMIALS
396 |                     AND DERIVATIVES VIA RECURSION RELATIONS
397 |             */
398 |                     if (n === m) {
399 |                         this.p[m][n] = st * this.p[m - 1][n - 1];
400 |                         this.dp[m][n] = st * this.dp[m - 1][n - 1] + ct *
401 |                             this.p[m - 1][n - 1];
402 |                     } else if (n === 1 && m === 0) {
403 |                         this.p[m][n] = ct * this.p[m][n - 1];
404 |                         this.dp[m][n] = ct * this.dp[m][n - 1] - st * this.p[m][n - 1];
405 |                     } else if (n > 1 && n !== m) {
406 |                         if (m > n - 2) { this.p[m][n - 2] = 0; }
407 |                         if (m > n - 2) { this.dp[m][n - 2] = 0.0; }
408 |                         this.p[m][n] = ct * this.p[m][n - 1] - this.k[m][n] * this.p[m][n - 2];
409 |                         this.dp[m][n] = ct * this.dp[m][n - 1] - st * this.p[m][n - 1] -
410 |                             this.k[m][n] * this.dp[m][n - 2];
411 |                     }
412 |             
413 |             /*
414 |                     TIME ADJUST THE GAUSS COEFFICIENTS
415 |             */
416 |             
417 |                     this.tc[m][n] = this.c[m][n] + dt * this.cd[m][n];
418 |                     if (m !== 0) {
419 |                         this.tc[n][m - 1] = this.c[n][m - 1] + dt * this.cd[n][m - 1];
420 |                     }
421 |             
422 |             /*
423 |                     ACCUMULATE TERMS OF THE SPHERICAL HARMONIC EXPANSIONS
424 |             */
425 |                     par = ar * this.p[m][n];
426 |                     if (m === 0) {
427 |                         temp1 = this.tc[m][n] * this.cp[m];
428 |                         temp2 = this.tc[m][n] * this.sp[m];
429 |                     } else {
430 |                         temp1 = this.tc[m][n] * this.cp[m] + this.tc[n][m - 1] * this.sp[m];
431 |                         temp2 = this.tc[m][n] * this.sp[m] - this.tc[n][m - 1] * this.cp[m];
432 |                     }
433 |                     bt = bt - ar * temp1 * this.dp[m][n];
434 |                     bp += (this.fm[m] * temp2 * par);
435 |                     br += (this.fn[n] * temp1 * par);
436 |             /*
437 |                         SPECIAL CASE:  NORTH/SOUTH GEOGRAPHIC POLES
438 |             */
439 |                     if (st === 0.0 && m === 1) {
440 |                         if (n === 1) {
441 |                             pp[n] = pp[n - 1];
442 |                         } else {
443 |                             pp[n] = ct * pp[n - 1] - k[m][n] * pp[n - 2];
444 |                         }
445 |                         parp = ar * pp[n];
446 |                         bpp += (this.fm[m] * temp2 * parp);
447 |                     }
448 |                 }
449 |             }
450 |             
451 |             bp = (st === 0.0 ? bpp : bp / st);
452 |             /*
453 |                 ROTATE MAGNETIC VECTOR COMPONENTS FROM SPHERICAL TO
454 |                 GEODETIC COORDINATES
455 |             */
456 |             bx = -bt * ca - br * sa;
457 |             by = bp;
458 |             bz = bt * sa - br * ca;
459 |             
460 |             /*
461 |                 COMPUTE DECLINATION (DEC), INCLINATION (DIP) AND
462 |                 TOTAL INTENSITY (TI)
463 |             */
464 |             bh = Math.sqrt((bx * bx) + (by * by));
465 |             ti = Math.sqrt((bh * bh) + (bz * bz));
466 |             dec = this._rad2deg(Math.atan2(by, bx));
467 |             dip = this._rad2deg(Math.atan2(bz, bh));
468 |             
469 |             /*
470 |                 COMPUTE MAGNETIC GRID VARIATION IF THE CURRENT
471 |                 GEODETIC POSITION IS IN THE ARCTIC OR ANTARCTIC
472 |                 (I.E. GLAT > +55 DEGREES OR GLAT < -55 DEGREES)
473 |                 OTHERWISE, SET MAGNETIC GRID VARIATION TO -999.0
474 |             */
475 |             
476 |             if (Math.abs(glat) >= 55.0) {
477 |                 if (glat > 0.0 && glon >= 0.0) {
478 |                     gv = dec - glon;
479 |                 } else if (glat > 0.0 && glon < 0.0) {
480 |                     gv = dec + Math.abs(glon);
481 |                 } else if (glat < 0.0 && glon >= 0.0) {
482 |                     gv = dec + glon;
483 |                 } else if (glat < 0.0 && glon < 0.0) {
484 |                     gv = dec - Math.abs(glon);
485 |                 }
486 |                 if (gv > 180.0) {
487 |                     gv -= 360.0;
488 |                 } else if (gv < -180.0) { gv += 360.0; }
489 |             }
490 |             
491 |             return {dec: dec, dip: dip, ti: ti, bh: bh, bx: bx, by: by, bz: bz, lat: glat, lon: glon, gv: gv, epoch: this.wmm.epoch};
492 |         },
493 |         
494 |         
495 |         // Converts a date to decimal years
496 |         _decimalDate: function(date) {
497 |             date = date || new Date();
498 |             var year = date.getFullYear(),
499 |                 daysInYear = 365 +
500 |                     (((year % 400 === 0) || (year % 4 === 0 && (year % 100 > 0))) ? 1 : 0),
501 |                 msInYear = daysInYear * 24 * 60 * 60 * 1000;
502 | 
503 |             return date.getFullYear() + (date.valueOf() - (new Date(year, 0)).valueOf()) / msInYear;
504 |         },
505 |         // Radian to degrees
506 |         _rad2deg: function(rad) {
507 |             return rad * (180 / Math.PI);
508 |         }, 
509 |         // Degrees to radians
510 |         _deg2rad: function(deg) {
511 |             return deg * (Math.PI / 180);
512 |         }, 
513 |         
514 |         
515 |         // Converts the WMM.COF text to a JSON object usable by geoMagFactory()
516 |         _cof2Obj: function(cof) {
517 |             'use strict';
518 |             var modelLines = cof.split('\n'),
519 |                 wmm = [],
520 |                 i, vals, epoch, model, modelDate;
521 |             for (i in modelLines) {
522 |                 if (modelLines.hasOwnProperty(i)) {
523 |                     vals = modelLines[i].replace(/^\s+|\s+$/g, "").split(/\s+/);
524 |                     if (vals.length === 3) {
525 |                         epoch = parseFloat(vals[0]);
526 |                         model = vals[1];
527 |                         modelDate = vals[2];
528 |                     } else if (vals.length === 6) {
529 |                         wmm.push({
530 |                             n: parseInt(vals[0], 10),
531 |                             m: parseInt(vals[1], 10),
532 |                             gnm: parseFloat(vals[2]),
533 |                             hnm: parseFloat(vals[3]),
534 |                             dgnm: parseFloat(vals[4]),
535 |                             dhnm: parseFloat(vals[5])
536 |                         });
537 |                     }
538 |                 }
539 |             }
540 |             
541 |             return {epoch: epoch, model: model, modelDate: modelDate, wmm: wmm};
542 |         }
543 |         
544 |         
545 |     });
546 | 
547 | });


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