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LatLon.distHaversine = function(lat1, lon1, lat2, lon2) {
var R = 6371; // earth's mean radius in km
var dLat = (lat2-lat1).toRad();
var dLon = (lon2-lon1).toRad();
lat1 = lat1.toRad(), lat2 = lat2.toRad();
var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
Math.cos(lat1) * Math.cos(lat2) *
Math.sin(dLon/2) * Math.sin(dLon/2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
var d = R * c;
return d;
}
Number.prototype.toRad = function() { // convert degrees to radians
return this * Math.PI / 180;
}
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转化为:
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function countlength(lat1, lon1, lat2, lon2)
dim R
dim dLat
dim dLon
R = 6371
dLat = (lat2-lat1)*3.14159265/180
dLon = (lon2-lon1)*3.14159265/180
lat1 = lat1*3.14159265/180
lat2 = lat2*3.14159265/180
a = sin(dLat/2) * sin(dLat/2) + cos(lat1) * cos(lat2) * sin(dLon/2) * sin(dLon/2)
c = 2 * tan(sqr(a)/sqr(1-a)) '是不是这个地方有问题?如何修改?
d = R * c
countlength=d
end function
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