将十进制分数转换为十进制度数

How can convert degrees decimal minutes to decimal degrees
on NMEA 0183 standard GPS trackers send position as degrees decimal minutes and need to convert.

Inputs :

5546.263 /*(mean = 55° 46.263'N)*/
3739.712 /*(mean = 37° 39.712'E)*/

Outputs :

55.771050
37.661867

Some inputs have a zero at first , like as above (3739.712 came from GPS device like 03739.712)

I try to it my self but have problem on first step :)
first problem is how degrees decimal minutes can convert to decimal degrees

I don't know PHP, but if you can split the (string?) "5546.263" into 55 and 46.263 (degrees and decimal minutes), you can convert to decimal degrees with 55 + (46.263 / 60).

In other words, it is degrees + (minutes / 60).