I'm working through Robert's answer to this question on how to plot irregular raster data: https://gis.stackexchange.com/questions/79062/how-to-make-raster-from-irregular-point-data-without-interpolation/389910?noredirect=1#comment638566_389910 no2tc <- ncvar_get(nc, "DETAILED_RESULTS/nitrogendioxide_total_column") lat <- ncvar_get(nc, "PRODUCT/latitude") lon <- ncvar_get(nc, "PRODUCT/longitude") no2vec <- as.vector(no2tc) latvec <- as.vector(lat) lonvec <- as.vector(lon) df <- data.frame(lonvec,latvec) colnames(df) <- c('X', 'Y') e <- extent(df) My data very similar in format to the fake data created in his question and I got the following error: Error in extent(df[, 2:3]) : c("x", "y") %in% names(x) are not all TRUE Here is a sample of my data Z X Y 1 NA -84.17967 -118.36866 2 NA -84.22738 -117.62881 3 NA -84.27346 -116.88749 4 NA -84.31795 -116.14489 5 NA -84.36089 -115.40117 6 NA -84.40232 -114.65651 7 NA -84.44226 -113.91109 8 NA -84.48075 -113.16512 9 NA -84.51782 -112.41875 > df[,2:3] X Y 1 -84.17967 -118.36865997 2 -84.22738 -117.62880707 3 -84.27346 -116.88748932 4 -84.31795 -116.14488983 5 -84.36089 -115.40116882 The data has some NA values but obviously, I would want to ignore these. Can someone tell me why I might be getting this error?