rgee example #2.1

rgee_example_02.R

library(cptcity)
library(raster)
library(stars)
library(rgee)
library(sf)

ee_Initialize(drive = TRUE)

roi <- st_read(system.file("shape/nc.shp", package="sf")) %>% 
  st_bbox() %>% 
  st_as_sfc() %>% 
  sf_as_ee()

ee_search_dataset() %>%
  ee_search_title("mod13") %>%
  ee_search_title("1km") %>%
  ee_search_display()                 

modis_ndvi <- ee$ImageCollection("MODIS/006/MOD13A2")

getQABits <- function(image, qa) {
  # Convert decimal (character) to decimal (little endian)
  qa <- sum(2^(which(rev(unlist(strsplit(as.character(qa), "")) == 1))-1))
  # Return a single band image of the extracted QA bits, giving the qa value.
  image$bitwiseAnd(qa)$lt(1)
}

mod13A2_clean <- function(img) {
  # Extract the NDVI band
  ndvi_values <- img$select("NDVI")
  
  # Extract the quality band
  ndvi_qa <- img$select("SummaryQA")
  
  # Select only pixels with high confidence
  quality_mask <- getQABits(ndvi_qa, "11")
  
  # Mask pixels with value zero.
  ndvi_values$updateMask(quality_mask)
}

ndvi_composite <- modis_ndvi$
  filter(ee$Filter$date('2001-01-01', '2019-12-31'))$
  filter(ee$Filter$calendarRange(1, field = "month"))$
  map(mod13A2_clean)$
  median()

scale <- 0.0001
Map$setCenter(lon = -79,lat = 35,zoom = 5)
Map$addLayer(
  eeObject = ndvi_composite, 
  visParams = list(
    min = 0.2 / scale, 
    max = 0.7 / scale,
    palette = cpt("grass_ndvi", 10)
  )
) + Map$addLayer(roi)


mod_ndvi <- ee_as_raster(
  image = ndvi_composite,
  region = roi,
  dsn = "ndvi_data.tif",
  scale = 1000,
  via = 'drive'
)

Images

• https://user-images.githubusercontent.com/16768318/84625282-9376da00-aea8-11ea-9543-56412bb532aa.png
• https://user-images.githubusercontent.com/16768318/84594061-4138a900-ae15-11ea-815b-e6f123139a1f.png
• https://user-images.githubusercontent.com/16768318/84626248-6297a480-aeaa-11ea-9a8c-279ab504b0c7.png
• https://user-images.githubusercontent.com/16768318/84626755-506a3600-aeab-11ea-8289-02a7081eca25.gif

HI Cesar,
I am running the last part of the script and getting this error:
Error in py_get_attr_impl(x, name, silent) :
AttributeError: 'Geometry' object has no attribute 'geometry'

any idea on how it can be solved?

Hi! @Joy-Giovanni,

Thanks for taking the time to point out this error. I made some small changes ... let me know if it still doesn't work!

Thank you so much it is working perfectly!
Giovanni.

Cesar, I would like to make project based on rgee;
I would appreciate If I can get your email so I can tell you more about it and see if you can share some guidance on how I can proceed.
Best,
Giovanni