Downscale Function created for for hourly data in nc

CHANGELOG.md

@@ -45,6 +45,7 @@ For more information about this file see also [Keep a Changelog](http://keepacha
 - Added new feature of preparing initial conditions for MODIS LAI, AGB, ISCN SOC, and soil moisture across NA anchor sites.
 - Added GEDI AGB preparation workflow.
 - Added new feature of downloading datasets from the NASA DAAC ORNL database.
+- Extended downscale function and created 'downscale_hrly' so that it handles more frequent data
 - Added 'aggregate' as a new feature for downscaled data
 
 ### Fixed

modules/assim.sequential/NAMESPACE

@@ -18,6 +18,7 @@ export(Prep_OBS_SDA)
 export(Remote_Sync_launcher)
 export(SDA_OBS_Assembler)
 export(SDA_control)
+export(SDA_downscale_hrly)
 export(SDA_remote_launcher)
 export(SDA_timeseries_plot)
 export(adj.ens)
@@ -60,6 +61,7 @@ export(tobit_model_censored)
 export(y_star_create)
 import(furrr)
 import(lubridate)
+import(ncdf4)
 import(nimble)
 importFrom(dplyr,"%>%")
 importFrom(lubridate,"%m+%")

modules/assim.sequential/R/downscale_function_hrly.R

@@ -0,0 +1,103 @@
+#' SDA　Downscale Function for Hourly Data
+#' 
+#' This function uses the randomForest model to downscale forecast data (hourly) to unmodeled locations using covariates and site locations
+#' 
+#' @author Harunobu Ishii
+#' @param nc_file  In quotes, file path for .nc containing ensemble data.
+#' @param coords In quotes, file path for .csv file containing the site coordinates, columns named "lon" and "lat".
+#' @param yyyy In string, format is yyyy(year of interest)
+#' @param covariates SpatRaster stack, used as predictors in randomForest. Layers within stack should be named. Recommended that this stack be generated using 'covariates' instructions in assim.sequential/inst folder
+#' @return It returns the `downscale_output` list containing lists for the training and testing data sets, models, and predicted maps for each ensemble member.
+#' @export
+
+SDA_downscale_hrly <- function(nc_file, coords, yyyy, covariates){
+
+  # Read the input data and site coordinates
+  nc_data <- ncdf4::nc_open(nc_file)
+  on.exit(ncdf4::nc_close(nc_data))
+  input_data <- ncvar_get(nc_data, "NEE")
+  covariate_names <- names(covariates)
+
+
+  # Extract time and units
+  time <- nc_data$dim$time$vals
+  time_units <- nc_data$dim$time$units
+  time_origin_str <- substr(time_units, 12, 31)
+
+  # Check if timezone is specified in the time units string
+  if (grepl("UTC|GMT", time_units)) {
+    time_origin <- lubridate::ymd_hm(time_origin_str, tz = "UTC")
+  } else if (grepl("EST", time_units)) {
+    time_origin <- lubridate::ymd_hm(time_origin_str, tz = "EST")
+  } else {
+    time_origin <- lubridate::ymd_hm(time_origin_str, tz = "UTC")  # Default to UTC if not specified
+  }
+
+  # Timereadable
+  if (grepl("hours", time_units)) {
+    time_readable <- time_origin + dhours(time)
+  } else if (grepl("seconds", time_units)) {
+    time_readable <- time_origin + dseconds(time)
+  } else {
+    stop("Unsupported time units")
+  }
+
+  # Extract predictors from covariates raster using site coordinates
+  site_coordinates <- terra::vect(readr::read_csv(coords), geom=c("lon", "lat"), crs="EPSG:4326")
+  predictors <- as.data.frame(terra::extract(covariates, site_coordinates,ID = FALSE)) 
+
+  downscale_output<- list()
+
+  # Train & Test split
+  sample <- sample(1:nrow(predictors), size = round(0.75*nrow(predictors)))
+
+  # Predict for each time stamp of the year selected
+  time_indices <- which(year(time_readable) == yyyy)
+  for (index in time_indices) {
+    data <- input_data[index, , ]
+    carbon_data <- as.data.frame(data)
+    names(carbon_data) <- paste0("ensemble",seq(1:ncol(carbon_data)))
+
+    # Combine carbon data and covariates/predictors and split into training/test
+    full_data <- cbind(carbon_data, predictors)
+    train_data <- full_data[sample, ]
+    test_data <- full_data[-sample, ]
+
+    # Combine each ensemble member with all predictors
+    models <- list()
+    maps <- list()
+    predictions <- list()
+    ensembles <- list()
+    for (i in seq_along(carbon_data)) {
+      ensemble_col <- paste0("ensemble", i)
+      formula <- stats::as.formula(paste(ensemble_col, "~", paste(covariate_names, collapse = " + ")))
+      models[[i]] <- randomForest::randomForest(formula,
+                                                data = train_data,
+                                                ntree = 1000,
+                                                na.action = stats::na.omit,
+                                                keep.forest = TRUE,
+                                                importance = TRUE)
+
+      maps[[i]] <- terra::predict(covariates, model = models[[i]], na.rm = TRUE)
+      predictions[[i]] <- stats::predict(models[[i]], test_data)
+    }
+
+    # Organize the results into a single output list
+    curr_downscaled <- list( data = list(training = train_data, testing = test_data),
+                             models = models,
+                             maps = maps,
+                             predictions = predictions
+                            )
+
+    # Rename each element of the output list with appropriate ensemble numbers
+    for (i in 1:length(curr_downscaled$data)) {
+      names(curr_downscaled$data[[i]]) <- paste0("ensemble", seq(1:ncol(carbon_data)))
+    }
+    names(curr_downscaled$models) <- paste0("ensemble", seq(1:ncol(carbon_data)))
+    names(curr_downscaled$maps) <- paste0("ensemble", seq(1:ncol(carbon_data)))
+    names(curr_downscaled$predictions) <- paste0("ensemble", seq(1:ncol(carbon_data)))
+
+    downscale_output[[as.character(time_readable[index])]]<-curr_downscaled
+  }
+  return(downscale_output)
+}