Extracting points in sf object by attributes in R

Question

I created an sf object from a point shapefile and would like to create a new object by choosing points with certain attributes only. In that case, only those points which have "Survey Start" in the column Subcategor. Shifting thinking from sp/rgdal is hard. Apologies this example is not reproducible, but I hope it is simple enough to answer.

data_pts <- st_read("Point.shp")

# I tried two approaches. More traditional, and something tidyvers-ey
field_id_pts <- data_pts[data_pts$Subcategor == "Survey Start",]
field_id_pts <- data_pts %>% select(Subcategor == "Survey Start")

None of them work. Thanks in advance for help.

Your first option seems fine to me, on the second one try `filter`, `select` just select the column. — dieghernan, Mar 06 '20 at 20:50
If the first one didn't work, make sure you have `library(sf)` loaded before trying it. — SymbolixAU, Mar 06 '20 at 23:23
The first option definitely does not work. I did have `sf` library on (otherwise I could not use the function `st_read`) — MIH, Mar 09 '20 at 13:50

score 1 · Accepted Answer · answered Mar 06 '20 at 16:59

1

You could use subset to easily select the points based on the "Subcategor" variable.

field_id_pts <- subset(data_pts, data_pts$Subcategor == "Survey Start")

answered Mar 06 '20 at 16:59

Jonathan V. Solórzano

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Perfect, as simple as that - great! Thank you – MIH Mar 06 '20 at 17:01

Extracting points in sf object by attributes in R

1 Answers1