Latitude and Longitude Location Conversion and farthest point locator Javascript

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<Script Language = "JavaScript"> function calc(Location) { //Retrieve the DD/DMS option for (var i=0;i<Location.inputType.length;i++) { if (Location.inputType[i].checked) { var inputed = Location.inputType[i].value; } } if (inputed == "DD") { //Retrieve Lat and Lon information var lat = Location.Latitude.value; var lon = Location.Longitude.value; if (lat==null) var lat=0; if (lon==null) var lon=0; //Check if any error occurred if (isNaN(Location.Latitude.value) || isNaN(Location.Longitude.value)) { alert("Latitude and Longitude must be numeric"); } else if (lat < -90 || lat > 90 || lon < -180 || lon > 180) { alert("ERROR"); } else { //Retrieve the latitude direction for Degrees Decimal for (var i=0;i<Location.LatDirect.length;i++) { if (Location.LatDirect[i].checked) { var LatDirect = Location.LatDirect[i].value; } } //If the user does not click direct button, //then a positive latitude value regards North, negative latitude value regards South if (LatDirect==null) { if (lat<0) { LatDirect = "S"; Location.LatDirect[1].click(); } else { LatDirect ="N"; Location.LatDirect[0].click(); } } //Retrieve the longitude direction for Deg/Min/Sec for (var i=0;i<Location.LonDirect.length;i++) { if (Location.LonDirect[i].checked) { var LonDirect = Location.LonDirect[i].value; } } //If the user does not click direct button, //then a positive latitude value regards East, negative latitude value regards West if (LonDirect==null) { if (lon<0) { LonDirect = "W"; Location.LonDirect[1].click(); } else { LonDirect ="E"; Location.LonDirect[0].click(); } } //Change to absolute value lat = Math.abs(lat); lon = Math.abs(lon); Location.Latitude.value=lat; Location.Longitude.value=lon; setAllEnabled(Location); //Convert to Degree Minutes Seconds Representation LatDeg = Math.floor(lat); LatMin = Math.floor((lat-LatDeg)*60); LatSec = (Math.round((((lat - LatDeg) - (LatMin/60)) * 60 * 60) * 100) / 100 ) ; LonDeg = Math.floor(lon); LonMin = Math.floor((lon-LonDeg)*60); LonSec = (Math.round((((lon - LonDeg) - (LonMin / 60 )) * 60 * 60) * 100 ) / 100); //Copy result to the board Location.LatDeg.value=LatDeg; Location.LatMin.value=LatMin; Location.LatSec.value=LatSec; Location.LonDeg.value=LonDeg; Location.LonMin.value=LonMin; Location.LonSec.value=LonSec; if (LatDirect == "N") { Location.LatDMSDirect[0].click(); } else { Location.LatDMSDirect[1].click(); } if (LonDirect == "E") { Location.LonDMSDirect[0].click(); } else { Location.LonDMSDirect[1].click(); } clickedOption(Location); //Find the farthest Point Location farthestPoint(lat,lon,LatDeg,LonDeg,LatMin,LonMin,LatSec,LonSec,LatDirect,LonDirect); } } else if (inputed == "DMS") { //Retrieve Lat and Lon information var LatDeg = Location.LatDeg.value; var LatMin = Location.LatMin.value; var LatSec = Location.LatSec.value; var LonDeg = Location.LonDeg.value; var LonMin = Location.LonMin.value; var LonSec = Location.LonSec.value; // Assume the value to be zero if the user does not enter value if (LatDeg==null) LatDeg=0; if (LatMin==null) { LatMin=0; } if (LatSec==null) { LatSec=0; } if (LonDeg==null) LonDeg=0; if (LonMin==null) { LonMin=0 } if (LonSec==null){ LonSec=0; } //Check if any error occurred if (isNaN(Location.LatDeg.value) || isNaN(Location.LonDeg.value) || isNaN(Location.LatMin.value) || isNaN(Location.LonMin.value) || isNaN(Location.LatSec.value) || isNaN(Location.LonSec.value)) { alert("Latitude and Longitude must be numeric"); } else if (LatDeg != Math.round(LatDeg) || LonDeg != Math.round(LonDeg) || LatMin != Math.round(LatMin) || LonMin != Math.round(LonMin)) { alert("ERROR"); } else if (LatDeg < -90 || LatDeg > 90 || LonDeg < -180 || LonDeg > 180 || LatMin < -60 || LatMin > 60 || LonMin < -60 || LonMin > 60 || LatSec < -60 || LatSec > 60 || LonSec < -60 || LonSec > 60) { alert("ERROR"); } else { //If no error, then go on //Retrieve the latitude direction for Degrees Decimal for (var i=0;i<Location.LatDMSDirect.length;i++) { if (Location.LatDMSDirect[i].checked) { var LatDMSDirect = Location.LatDMSDirect[i].value; } } //If the user does not click direct button, //then a postive latitude value regards North, negative latitude value regards South if (LatDMSDirect==null) { if (LatDeg<0 || Location.LatDeg.value=="-0") { LatDMSDirect = "S"; Location.LatDMSDirect[1].click(); } else { LatDMSDirect ="N"; Location.LatDMSDirect[0].click(); } } //Retrieve the longitude direction for Deg/Min/Sec for (var i=0;i<Location.LonDMSDirect.length;i++) { if (Location.LonDMSDirect[i].checked) { var LonDMSDirect = Location.LonDMSDirect[i].value; } } //If the user does not click direct button, //then a positive latitude value regards East, negative latitude value regards West if (LonDMSDirect==null) { if (LonDeg<0 || Location.LonDeg.value=="-0") { LonDMSDirect = "W"; Location.LonDMSDirect[1].click(); } else { LonDMSDirect ="E"; Location.LonDMSDirect[0].click(); } } //Change to absolute value LatDeg = Math.abs(LatDeg); LonDeg = Math.abs(LonDeg); LatMin = Math.abs(LatMin); LonMin = Math.abs(LonMin); LatSec = Math.abs(LatSec); LonSec = Math.abs(LonSec); setAllEnabled(Location); // Convert to Decimal Degrees Representation var lat = LatDeg + (LatMin/60) + (LatSec / 60 / 60); var lon = LonDeg + (LonMin/60) + (LonSec / 60 / 60); if ( lat <= 90 && lon <= 180 && lat >=0 && lon >= 0 ) { //Copy the absolute value to the board Location.LatDeg.value=LatDeg; Location.LonDeg.value=LonDeg; Location.LatMin.value=LatMin; Location.LonMin.value=LonMin; Location.LatSec.value=LatSec; Location.LonSec.value=LonSec; // Rounding off lat = (Math.round(lat*1000000)/1000000); lon = (Math.round(lon*1000000)/1000000); //Copy result to the board Location.Latitude.value=lat; Location.Longitude.value=lon; if (LatDMSDirect == "N") { Location.LatDirect[0].click(); } else { Location.LatDirect[1].click(); } if (LonDMSDirect == "E") { Location.LonDirect[0].click(); } else { Location.LonDirect[1].click(); } clickedOption(Location); farthestPoint(lat,lon,LatDeg,LonDeg,LatMin,LonMin,LatSec,LonSec,LatDMSDirect,LonDMSDirect); } else alert("ERROR!!"); } } } function clickedOption(Location) { //Retrieve The DD/DMS Option for (var i=0;i<Location.inputType.length;i++) { if (Location.inputType[i].checked) { var inputed = Location.inputType[i].value; } } changeOption(Location,inputed); } function resetForm(Location) { changeOption(Location,"DD"); } function changeOption(Location,inputed) { if (inputed=="DD") { with (Location) { LatDeg.disabled=true; LonDeg.disabled=true; LatMin.disabled=true; LonMin.disabled=true; LatSec.disabled=true; LonSec.disabled=true; Latitude.disabled=false; Longitude.disabled=false; LatDirect[0].disabled=false; LonDirect[0].disabled=false; LatDirect[1].disabled=false; LonDirect[1].disabled=false; LatDMSDirect[0].disabled=true; LonDMSDirect[0].disabled=true; LatDMSDirect[1].disabled=true; LonDMSDirect[1].disabled=true; } } else if (inputed =="DMS") { with (Location){ Latitude.disabled=true; Longitude.disabled=true; LatDeg.disabled=false; LonDeg.disabled=false; LatMin.disabled=false; LonMin.disabled=false; LatSec.disabled=false; LonSec.disabled=false; LatDMSDirect[0].disabled=false; LonDMSDirect[0].disabled=false; LatDMSDirect[1].disabled=false; LonDMSDirect[1].disabled=false; LatDirect[0].disabled=true; LonDirect[0].disabled=true; LatDirect[1].disabled=true; LonDirect[1].disabled=true; } } } function setAllEnabled(Location) { with (Location) { Latitude.disabled=false; Longitude.disabled=false; LatDeg.disabled=false; LonDeg.disabled=false; LatMin.disabled=false; LonMin.disabled=false; LatSec.disabled=false; LonSec.disabled=false; LatDMSDirect[0].disabled=false; LonDMSDirect[0].disabled=false; LatDMSDirect[1].disabled=false; LonDMSDirect[1].disabled=false; LatDirect[0].disabled=false; LonDirect[0].disabled=false; LatDirect[1].disabled=false; LonDirect[1].disabled=false; } } function farthestPoint(lat,lon,LatDeg,LonDeg,LatMin,LonMin,LatSec,LonSec,LatDirect,LonDirect) { var farLat,farLon,farLat2,farLon2,farLatDeg,farLonDeg; var farLatMin,farLonMin,farLatSec,farLonSec,farLatDirect,farLonDirect; var dist; if (LatDirect == "N") { farLatDirect = "S"; } else { farLatDirect = "N"; } if (LonDirect == "E") { farLonDirect = "W"; } else { farLonDirect = "E"; } farLat = lat; farLatDeg = LatDeg; farLatMin = LatMin; farLatSec = LatSec; farLon = 180 - Math.abs(lon); //Method 1 farLonDeg = Math.floor(farLon); farLonMin = Math.floor((farLon-farLonDeg)*60); farLonSec = (Math.round((((farLon - farLonDeg) - (farLonMin / 60 )) * 60 * 60) * 100 ) / 100); //Method 2 /* farLonSec = 60 - LonSec; if (farLonSec == 60) { farLonSec=0; } if (farLonSec >0) { farLonMin = 60 - LonMin - 1; } else { farLonMin = 60 - LonMin ; } if (farLonMin ==60) { farLonMin =0; } if (farLonMin >0) { farLonDeg = 180 - Math.abs(farLonDeg) - 1; } else { farLonDeg = 180 - Math.abs(farLonDeg); } */ farLon = Math.round(farLon*1000000)/1000000; farLonSec = Math.round(farLonSec*100)/100; elev = 200; farElev = 200; var dist = distance(lat,LatDirect,lon,LonDirect,elev,farLat,farLatDirect,farLon,farLonDirect,farElev); var alertMsg=""; alertMsg+=("The location you entered is : " + "\n\n" + "Latitude: " + lat + " " + LatDirect + "\n" + "Degrees: " + LatDeg + " Minutes: " + LatMin + " Seconds: " + LatSec + " " + LatDirect + "\n\n" + "Longitude: " + lon + " " + LonDirect + "\n" + "Degrees: " + LonDeg + " Minutes: " + LonMin + " Seconds: " + LonSec + " " + LonDirect + "\n\n" + "---------------------------------------------------------------" + "\n"); alertMsg+=("The farthest location from the point you entered is : " + "\n\n" + "Latitude: " + farLat + " " + farLatDirect + "\n" + "Degrees: " + farLatDeg + " Minutes: " + farLatMin + " Seconds: " + farLatSec + " " + farLatDirect + "\n\n" + "Longitude: " + farLon + " " + farLonDirect + "\n" + "Degrees: " + farLonDeg + " Minutes: " + farLonMin + " Seconds: " + farLonSec + " " + farLonDirect + "\n\n"); alertMsg+=("---------------------------------------------------------------" + "\n"); alertMsg+=("Distance: " + dist + " km "); alert(alertMsg); } function distance(lat,LatDirect,lon,LonDirect,elev,lat2,ptDirect,lon2,ptLonDirect,ptElev) { var radLat,radLon,radLat2,radLon2; if (ptDirect == "S") lat2 = lat2*-1; if (ptLonDirect == "W") lon2 = lon2*-1; if (LatDirect == "S") lat = lat*-1; if (LonDirect == "W") lon = lon*-1; var radian = 180/Math.PI; radLat=lat/radian; radLon=lon/radian; radLat2=lat2/radian; radLon2=lon2/radian; var dist = calcDistance(radLat,radLon,elev,radLat2,radLon2,ptElev); dist = Math.round(dist*100)/100; return dist; } // calculate the distance between two coordinates function calcDistance(lat1,long1,elev,lat2,long2,ptElev) { var earthEquatorialRadius = 6378.14; // in kilometers var earthFlattened = 1/298.257; var exCentricityEarth = 0.08181922; var radian = 180/Math.PI; meanPosLat = (lat1+lat2)/2; meanNegLat = (lat1-lat2)/2; lambda = (long1-long2)/2; with(Math) { si = pow(sin(meanNegLat)*cos(lambda),2)+pow(cos(meanPosLat)*sin(lambda),2); co = pow(cos(meanNegLat)*cos(lambda),2)+pow(sin(meanPosLat)*sin(lambda),2); delta = atan(sqrt(si/co)); ra = sqrt(si*co)/delta; di = 2*delta*earthEquatorialRadius; ha =(3*ra-1)/2/co; hb =(3*ra+1)/2/si; distances = di*(1+earthFlattened*ha*pow(sin(meanPosLat)*cos(meanNegLat),2)-earthFlattened*hb*pow(cos(meanPosLat)*sin(meanNegLat),2)); } //Taking elevation into consideration var totalElev, elevDist totalElevDist = Math.abs(elev - ptElev); //Convert back to km totalElevDist = totalElevDist / 1000; elevDist = Math.sqrt((distances * distances) + (totalElevDist * totalElevDist)); return elevDist; } </Script> <FORM NAME = "Locations"> <B><INPUT TYPE=RADIO NAME="inputType" VALUE="DD" checked onclick="clickedOption(this.form)"> Degrees Decimal</B> <BR>Latitude: <INPUT NAME ="Latitude" TYPE=TEXT size=5> North <INPUT TYPE=RADIO NAME="LatDirect" VALUE="N"> South <INPUT TYPE=RADIO NAME="LatDirect" VALUE="S" > <BR>Longitude: <INPUT NAME ="Longitude" TYPE=TEXT size=5> East <INPUT TYPE=RADIO NAME="LonDirect" VALUE="E"> West <INPUT TYPE=RADIO NAME="LonDirect" VALUE="W"> <P> <B><BR><INPUT TYPE=RADIO NAME="inputType" VALUE="DMS" onclick="clickedOption(this.form)"> Degrees, Minutes, Seconds</B> <BR><B>Latitude</B> <BR>Degrees: <INPUT NAME ="LatDeg" TYPE=TEXT size=5 Disabled> Minutes: <INPUT NAME ="LatMin" TYPE=TEXT size=5 Disabled> Seconds: <INPUT NAME ="LatSec" TYPE=TEXT size=5 Disabled> <BR> North <INPUT TYPE=RADIO NAME="LatDMSDirect" VALUE="N" Disabled> South <INPUT TYPE=RADIO NAME="LatDMSDirect" VALUE="S" Disabled> <BR><B>Longitude</B> <BR>Degrees: <INPUT NAME ="LonDeg" TYPE=TEXT size=5 Disabled> Minutes: <INPUT NAME ="LonMin" TYPE=TEXT size=5 Disabled> Seconds: <INPUT NAME ="LonSec" TYPE=TEXT size=5 Disabled> <BR>East <INPUT TYPE=RADIO NAME="LonDMSDirect" VALUE="E" Disabled> West <INPUT TYPE=RADIO NAME="LonDMSDirect" VALUE="W" Disabled> <BR><INPUT Value = "Calculate" TYPE = "button" onclick="calc(this.form)" > <INPUT NAME = "Reset" TYPE = "reset" Value="Clear" onclick="resetForm(this.form)"> <BR> </BODY> </HTML>

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