search

cyang-kth / fmm

Fast map matching, an open source framework in C++
https://fmm-wiki.github.io/
Apache License 2.0
892 stars 215 forks source link

the output issue #144

Closed M-Efforts closed 3 years ago

M-Efforts commented 3 years ago

Hello, I would like to ask why the SPdist of the two GPS points I output is very small, with an order of 10-4? How can I turn it into a meter scale? For example, if I put in two coordinates (34.231594, 108.927851) and (34.231584, 108.92837), I get the “spdist ” is 0.000519009, is this result right?

cyang-kth commented 3 years ago

The unit is in degree (same as your GPS coordinates) and you need to convert to meter by multiplied with 1.1x10^5 for approximation.

https://github.com/cyang-kth/fmm/issues/143#issuecomment-729001757

https://github.com/cyang-kth/fmm/issues/143#issuecomment-729005624

M-Efforts commented 3 years ago

Ok, I just saw that, I need to multiply by 111,000, thank you very much