parse strings that have both lat and lon

[sckott]

the c++ code only does one or the other

so make c++ stuff to do the parsing, then u can feed that in

[sckott]

e.g,. N 04.25164, E 101.70695

[sckott]

from noam

c("N 04.1683, E 101.5823", "N 04.25164, E 101.70695", "N04.82344, E101.61320", 
"N05.03062, E101.75172", "N05.03062,E101.75172", "N4.9196, E101.345", 
"N4.9196, E101.346", "N4.9196, E101.347")

Function I (he) wrote to deal with these (I knew the hemisphere):

latlong_to_lat_long <- function(latlong) {
  caps <- stri_match_first_regex(latlong, "N\\h*([\\d\\.]+),\\h*E\\h*([\\d\\.]+)")
  lat <- as.double(caps[,2])
  long <- as.double(caps[,3])
  return(list(lat = lat, long = long))
}

[sckott]

a bit of experimenting on branch parse-string-lat-and-lon

[AlbanSagouis]

Hi @sckott,

I wrote a function that does that (here https://github.com/AlbanSagouis/iClean/blob/master/R/coordinate_conversions.R). It is not elegant, it is pure R code (no Rcpp), it depends on biogeo::dmsparse and it is highly redundant with parzer. But it works on the example you provided here and on other formats.

            c('52.473892, 13.40444',
            '52,473892; 13,40444', '52,473892 13,40444',
            '52°28’26”, 13°24’16”', '52°28’26”N, 13°24’16”E','N52°28’26”, E13°24’16”',
            '52°28’26’’, 13°24’16’’','52°28’26"’, 13°24’16"', "52°28'26'', 13°24'16''",
            '52 28 26, 13 24 16', '52 28 26.13 24 16', '52°28’26” 13°24’16”',
            'S52°28’26”, W13°24’16”', '52°28’26”S, 13°24’16”W', 'S52°28’26” E13°24’16”',
            '13.40444E, 52.473892N', '13°24’16”E, 52°28’26”N',
            '13.40444, 52.473892', '13°24’16”, 52°28’26”',

            # Examples from here https://www.codeproject.com/articles/15659/longitude-latitude-string-parser-and-formatter
            '45:26:46N, 65:56:55W',
            '45:26:46.302N, 65:56:55.903W',
            '45°26’21"N, 65°58’36"W',
            '45N26 21, 65W58 36',
            '45.446195N, 65.948862W',
            '45.446195, -65.948862',
            'N45° 26.7717’, W65° 56.93172’',

            # example from parzer test
            "45W54.2356, 45N54.2356",

            # example from parzer
            "N 04.1683, E 101.5823", "N 04.25164, E 101.70695", "N04.82344, E101.61320",
              "N05.03062, E101.75172", "N05.03062,E101.75172", "N4.9196, E101.345",
              "N4.9196, E101.346", "N4.9196, E101.347",
            # expected errors
            '52°28’260”, 13°64’16”', '92°28’26”, 190°24’16”'

I would be happy to contribute to your branch parse-string-lat-and-lon. Could that be useful?

[sckott]

thanks very much for dropping in here @AlbanSagouis !

Looks good, but this package has all the work done on the C++ side, with the R side only being a thin function interface over the C++ code. Do you think you could translate your R code to C++?

[AlbanSagouis]

Well, I'll try translating my code to Rcpp/C++. It is not my main project so please let me know if you need it ready for milestone 0.2.

Thanks for updating the branch!

[sckott]

thx. let me know if you have any questions