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This code will convert longitude and latitude in D'M'S format into a decimal format. It also contains the function to do the reverse.
The example below does contain a couple of strange lines of code. You will notice that we seperate the integer and floating point values from the decimal format using a set of string functions, instead of using the math round or floor functions. This fixes a 'feature' in some versions of PHP that causes it to behave in an unpredictable manner when handling math with floating points.
For example, if you include the code print(91.1 - 91); in PHP you may not get the result you expect. You will actually get
0.099999999999994, not 1 ! This tends to throw of the calculations in the example.
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<?php
function DMStoDEC($deg,$min,$sec)
{
// Converts DMS ( Degrees / minutes / seconds )
// to decimal format longitude / latitude
return $deg+((($min*60)+($sec))/3600);
}
function DECtoDMS($dec)
{
// Converts decimal longitude / latitude to DMS
// ( Degrees / minutes / seconds )
// This is the piece of code which may appear to
// be inefficient, but to avoid issues with floating
// point math we extract the integer part and the float
// part by using a string function.
$vars = explode(".",$dec);
$deg = $vars[0];
$tempma = "0.".$vars[1];
$tempma = $tempma * 3600;
$min = floor($tempma / 60);
$sec = $tempma - ($min*60);
return array("deg"=>$deg,"min"=>$min,"sec"=>$sec);
}
?>
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 misc_6.zip
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Conversion tables A-K