'sa' argument in 'MPG' doesn't work as expected

[achubaty]

from the example in MPG():

library(igraph)
library(raster)

tiny <- raster(system.file("extdata/tiny.asc", package = "grainscape"))
tinyCost <- reclassify(tiny, rcl = cbind(c(1, 2, 3, 4), c(1, 5, 10, 12)))
tinyPatchMPG <- MPG(cost = tinyCost, patch = (tinyCost == 1))
plot(tinyPatchMPG, col = c("grey", "black"), legend = FALSE)

## Produce a patch-based MPG with a study area consisting of half of the map
tinySa <- tinyCost
tinySa[] <- 1
tinySa[1:5000] <- 0
tinySaMPG <- MPG(cost = tinyCost, patch = (tinyCost == 1), sa = tinySa)
plot(tinySaMPG)

Without looking more closely, this may simply be an issue with how the mpgPlot is being created, rather than an issue with the mpg itself.

[ecologics]

I think we should remove the sa argument. Andrew Fall's code allowed the user to specify an SA because cropping maps was not as straightforward 15 years ago as it is now. Sam's code didn't include this, I presume. So I say remove the argument and let users pre-crop if they think it is necessary.

[achubaty]

works for me. it's an easy removal, and trivial for the user to pre-crop.