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rraster

Producing a moving time sequence in raster

I have a raster that looks like this:

library(raster)

# Create data
set.seed(123)
r <- raster(ncols=10, nrows=10)
r[] <- sample(10:360, ncell(r),replace = T)
crs(r) <- "+proj=lcc +lat_1=48 +lat_2=33 +lon_0=-100 +ellps=WGS84"
projection(r)
plot(r)

enter image description here

For each grid, the raster contains a day of the year as values. I am looking for a method that generates a map (animation maybe) which goes from day 1 to day 365 and when the map reaches the day which matches with the day of a grid, the grid should turn green.

I am sorry but I cannot produce what I have tried since I have no clue whether such thing is possible in R.

Thank you

EDIT

One way I could think of is run a loop like this:

for(i in 2:365){

    breakpoints <- c(1,i,365)
    colors <- c("green4","white")
    plot(r, breaks = breakpoints,col=colors)
}

Save the ouptut of each loop as .png and then develop a .gif image of it

Solution

  • Using a loop, you can reclassify your raster into a binary raster (0 if lower or equal to the day, 1 if higher). Then, you can use the animation package to create the gif. 

    library(animation)
ani.options(interval=.05)

saveGIF({
  for (i in 1:365){
    m <- c(1, i, 0,  i, 365, 1)
    rclmat <- matrix(m, ncol=3, byrow=TRUE)
    rc <- reclassify(r, rclmat)

    plot(rc, col=c("green3", "white"), legend=FALSE, main = paste("Day", i))
  }
})

    Demo (200 days)

    enter image description here