I wish to plot some maps of Denmark using the new sf package and geom_sf() from ggplot2. I have a shapefile from a public map service, with a total of 4 files (DK.shp, DK.dbf, DK.shf and DK.prj). I have made the data available here in a zip-file (let me know if there is a better way to share files on Stack Overflow, I was not sure).
In R I try to load the file:
library(sf)
devtools::dev_mode(on = TRUE)
#devtools::install_github('tidyverse/ggplot2')
library(ggplot2)
d <- st_read('DK/DK.shp')
ggplot(d) +
geom_sf()
nc <- st_read(system.file("shape/nc.shp", package="sf"))
ggplot(nc) +
geom_sf()
geom_sf() plots the buildin nc.shp file just as expected, but DK.shp makes it return:
Error in x %*% Mat : non-conformable arguments In addition: There were 50 or more warnings (use warnings() to see the first 50)
The 50 warnings mentioned are all of the type:
1: In matrix(vec, ncol(m), nrow(m)) :
data length [2] is not a sub-multiple or multiple of the number of rows [3]
I am not sure whether this is a problem with the data-file I supply, or a bug in either sf or ggplot2. Any suggestions on how to resolve this?
Update Looking into the data returned by st_geometry() i found the following:
x <- st_geometry(d[1,])
unlist(x)
# [1] 695222.0 695157.0 694574.5 693521.3 693590.6 693091.5 694813.6 694669.2 694190.6
# [10] 693295.8 692494.8 692655.9 693205.8 693998.4 695060.1 696658.0 697494.1 697847.6
# [19] 699947.6 700876.2 700936.4 702302.0 702727.3 702762.6 703223.3 703771.5 704180.7
# [28] 704991.5 704650.9 706955.0 708027.2 710597.9 710211.5 710128.9 710127.7 709773.2
# [37] 709965.2 708919.0 710098.1 710272.9 710586.6 712156.8 710876.0 710567.9 710041.6
# [46] 709731.5 708333.8 707001.3 707546.4 707193.8 706598.1 706370.5 704816.7 705153.2
# [55] 704208.8 704209.4 702438.4 702290.3 702017.5 701601.2 700813.9 700244.4 698705.2
# [64] 697584.8 695462.3 695222.0 6195729.1 6196153.6 6197058.5 6197735.0 6198228.8 6198687.0
# [73] 6199968.8 6200923.1 6201422.3 6201743.9 6203045.2 6204716.4 6205660.8 6205964.5 6207435.3
# [82] 6207247.1 6207387.4 6207111.0 6208095.2 6208737.5 6209758.0 6209820.5 6209795.2 6209941.6
# [91] 6209663.9 6209741.5 6209669.6 6210534.0 6211238.2 6211301.4 6211441.3 6211409.8 6210281.9
# [100] 6209192.3 6208759.1 6207688.6 6206301.1 6205454.5 6204600.1 6204566.5 6203154.7 6201390.7
# [109] 6199999.8 6199645.5 6199286.7 6199607.3 6199116.3 6199058.5 6198042.2 6197785.1 6198202.3
# [118] 6198169.9 6197827.8 6196050.1 6194848.5 6194665.8 6194474.5 6193641.8 6193609.7 6193729.3
# [127] 6193661.6 6196020.7 6197222.2 6196682.2 6195683.5 6195729.1 -999.0 -999.0 -999.0
# [136] -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0
# [145] -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0
# [154] -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0
# [163] -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0
# [172] -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0
# [181] -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0
# [190] -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0 -999.0
nx <- st_geometry(nc[1,])
unlist(nx)
# [1] -81.47276 -81.54084 -81.56198 -81.63306 -81.74107 -81.69828 -81.70280 -81.67000 -81.34530
# [10] -81.34754 -81.32478 -81.31332 -81.26624 -81.26284 -81.24069 -81.23989 -81.26424 -81.32899
# [19] -81.36137 -81.36569 -81.35413 -81.36745 -81.40639 -81.41233 -81.43104 -81.45289 -81.47276
# [28] 36.23436 36.27251 36.27359 36.34069 36.39178 36.47178 36.51934 36.58965 36.57286
# [37] 36.53791 36.51368 36.48070 36.43721 36.40504 36.37942 36.36536 36.35241 36.36350
# [46] 36.35316 36.33905 36.29972 36.27870 36.28505 36.26729 36.26072 36.23959 36.23436
So the shapefile I am trying to read contains the values in a different format or something. Also, what is going on with all the -999 values? How to I deal with this?
I'll file this as an issue; your geometry contains Z coordinates, and right now geom_sf doesn't like that. Try
ggplot(st_zm(d)) + geom_sf()
to drop the Z coordinate from your polygon nodes. (Issue raised here)