Converting decimal degrees (longitude & latitude) to UTM WGS84 in R? (Southern hemisphere)

Question

I'm trying to convert some longitude and latitude coordinates to UTM WGS84 projection. I'm using rgdal, although I can accommodate to other package (in R). I read the data and converted it to a SpatialPoints object:

coordinates(res) <- ~Lat_dec + Lon_dec
proj4string(res) <- CRS('+proj=longlat +datum=WGS84')

my points:

res
SpatialPoints:
   Lon_dec   Lat_dec
35 -78.60972 -9.073333
36 -78.61806 -9.078611
37 -78.60889 -9.093611
38 -78.59167 -9.088889
39 -78.57917 -9.100833
40 -78.56833 -9.112778
41 -78.59278 -9.113333
42 -78.61139 -9.119167
43 -78.57778 -9.122778
44 -78.56889 -9.135833
45 -78.59278 -9.137222
46 -78.60222 -9.160278
47 -78.57472 -9.152778
48 -78.59583 -9.152778
Coordinate Reference System (CRS) arguments: +proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0 

---

The following error is no longer produced since swapping the coordinates to negative values (south america) Now, when I try to transform the points using spTransform(res, CRS('+proj=utm +zone=17 ellps=WGS84')) I get an error and a warning:

non finite transformation detected:
  Lat_dec   Lon_dec                     
  9.073333 78.609722       Inf       Inf 
Error in spTransform(res, CRS("+proj=utm +zone=17 ellps=WGS84")) : 
failure in points 1
 In addition: Warning message:
 In spTransform(res, CRS("+proj=utm +zone=17 ellps=WGS84")) :
   14 projected point(s) not finite

When I try to convert using project(coordinates(res), '+proj=utm +zone=17 ellps=WGS84') I get the projection:

   [,1] [,2]
 [1,]  Inf  Inf
 [2,]  Inf  Inf
 [3,]  Inf  Inf
 [4,]  Inf  Inf
 [5,]  Inf  Inf
 [6,]  Inf  Inf
 [7,]  Inf  Inf
 [8,]  Inf  Inf
 [9,]  Inf  Inf
[10,]  Inf  Inf
[11,]  Inf  Inf
[12,]  Inf  Inf
[13,]  Inf  Inf
[14,]  Inf  Inf
Warning message:
In project(coordinates(res), "+proj=utm +zone=17 ellps=WGS84") :
  14 projected point(s) not finite

---

Changed according to the suggestions below and now this is produced

> project(coordinates(res), '+proj=utm +zone=17 ellps=WGS84')
          [,1]     [,2]
 [1,] 762744.8 -1003824
 [2,] 761824.4 -1004402
 [3,] 762821.6 -1006069
 [4,] 764719.2 -1005559
 [5,] 766085.1 -1006890
 [6,] 767267.6 -1008219
 [7,] 764579.0 -1008263
 [8,] 762528.0 -1008895
 [9,] 766221.6 -1009319
[10,] 767189.3 -1010770
[11,] 764561.3 -1010906
[12,] 763505.8 -1013450
[13,] 766535.2 -1012641
[14,] 764213.9 -1012625

Which are undeniably wrong. The latitude should be positive and near 899####.

Answer 1

Add a +south parameter to the utm PROJ.4 string. That will automatically add a false northing value of 10000000 meters.

"+proj=utm +zone=17 +south=T ellps=WGS84"

Note: I can't find the "=T" in the PROJ.4 documentation on the "+south" parameter, but two people agree that it works when using R.

Answer 2

Latitude is Y. Try coordinates(res) <- ~ Long_dec + Lat_dec

Answer 3

If you're in zone 17 (panama?), those longitudes should be negative.