R programming How to convert Tiff to IMG ERDAS format

Question

I have multiple images in Tiff format. I need to perform 2 operations on these images:

1.  First multiply them by 2 , 
2.  Next, convert them to IMG (ERDAS) format (with the same name as input file)

Like so:

my input:

MOD11A1_2009-04-01.LST_Day_1km.tiff

output:

MOD11A1_2009-04-01.LST_Day_1km.img

How can I do this in R?

Answer 1

This code should work:

library(raster)
input <- list.files(pattern='tif$')
output <- gsub("tif", "img", input)

for (i in seq(along=input)) {
   r <- raster(input[i])
   # using "2 byte unsigned integer" data type
   r <- calc(r, fun = function(x) x * 2, datatype='INT2U', filename = output[i])
}