I used the nsidcICE function located here: <https://github.com/cran/raster/blob/master/R/nsidcICE.R> and the following code to open a sea ice raster file. However, I would like to overlap vector points and "zoom in" on the raster to the Canadian Arctic (lat: 72 to 75, long: -90 to -80). I am new to R and GIS.

```
library(raster)
library(graticule)
library(rgdal)

tfile <- system.file("extdata",  "nt_20140728_f17_v1.1_n.bin", package = "graticule")
ice<-.rasterFromNSIDCFile("nt_20140728_f17_v1.1_n.bin")

meridians <- seq(-180, 160, by = 20)
parallels <- c(-80, -73.77, -68, -55, -45)
mlim <- c(-180, 180)
plim <- c(-88, -50)
grat <- graticule(lons = meridians, lats = parallels, xlim = mlim, ylim =     plim, proj = projection(ice))
labs <- graticule_labels(meridians, parallels, xline = -45, yline = -60, proj = projection(ice))
plot(ice, axes = FALSE)
plot(grat, add = TRUE, lty = 3)
text(labs, lab = parse(text= labs$lab), col= c("firebrick", "darkblue")[labs$islon + 1], cex = 0.85)
title(sprintf("Sea ice concentration %s", gsub(".bin", "", basename(ice))), cex.main = 0.8) 
title(sub = projection(ice), cex.sub = 0.6)

```