From e13e4a575d4eed205a319f0cad180d570e22c1e0 Mon Sep 17 00:00:00 2001
From: Andrea Manica <am315@cam.ac.uk>
Date: Thu, 21 Dec 2023 15:28:38 +0000
Subject: [PATCH] Get resolution of a dataset

---
 NAMESPACE                          |  1 +
 R/get_res.R                        | 30 ++++++++++++++++++++++++++++++
 man/get_resolution.Rd              | 23 +++++++++++++++++++++++
 vignettes/a0_pastclim_overview.Rmd |  7 +++++++
 4 files changed, 61 insertions(+)
 create mode 100644 R/get_res.R
 create mode 100644 man/get_resolution.Rd

diff --git a/NAMESPACE b/NAMESPACE
index d3d29b08..adfbd473 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -17,6 +17,7 @@ export(get_downloaded_datasets)
 export(get_ice_mask)
 export(get_land_mask)
 export(get_mis_time_steps)
+export(get_resolution)
 export(get_time_bp_steps)
 export(get_time_ce_steps)
 export(get_time_steps)
diff --git a/R/get_res.R b/R/get_res.R
new file mode 100644
index 00000000..6b05ea49
--- /dev/null
+++ b/R/get_res.R
@@ -0,0 +1,30 @@
+#' Get resolution of a given dataset
+#'
+#' Get the resolution of a given dataset.
+#'
+#' @param dataset string defining dataset to be downloaded (a list of possible
+#' values can be obtained with [list_available_datasets()]). If set to
+#' "custom", then a single nc file is used from "path_to_nc"
+#' @param path_to_nc the path to the custom nc file containing the palaeoclimate
+#' reconstructions. All the variables of interest need to be included in
+#' this file.
+#' @returns a vector of resolution in the x and y axes
+#'
+#' @export
+
+get_resolution <- function(dataset, path_to_nc = NULL) {
+  check_dataset_path(dataset = dataset, path_to_nc = path_to_nc)
+
+  if (is.null(path_to_nc)) {
+    possible_files <- dataset_list_included$file_name[dataset_list_included$dataset == dataset]
+    possible_files <- possible_files[possible_files %in% list.files(get_data_path())]
+    # check that at least one file is available
+    if (length(possible_files) == 0) {
+      stop("no variable has been downloaded for this dataset yet")
+    }
+    path_to_nc <- file.path(get_data_path(), possible_files[1])
+  }
+
+  climate_nc <- terra::rast(path_to_nc, subds = 1)
+  return(terra::res(climate_nc))
+}
diff --git a/man/get_resolution.Rd b/man/get_resolution.Rd
new file mode 100644
index 00000000..00026703
--- /dev/null
+++ b/man/get_resolution.Rd
@@ -0,0 +1,23 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/get_res.R
+\name{get_resolution}
+\alias{get_resolution}
+\title{Get resolution of a given dataset}
+\usage{
+get_resolution(dataset, path_to_nc = NULL)
+}
+\arguments{
+\item{dataset}{string defining dataset to be downloaded (a list of possible
+values can be obtained with \code{\link[=list_available_datasets]{list_available_datasets()}}). If set to
+"custom", then a single nc file is used from "path_to_nc"}
+
+\item{path_to_nc}{the path to the custom nc file containing the palaeoclimate
+reconstructions. All the variables of interest need to be included in
+this file.}
+}
+\value{
+a vector of resolution in the x and y axes
+}
+\description{
+Get the resolution of a given dataset.
+}
diff --git a/vignettes/a0_pastclim_overview.Rmd b/vignettes/a0_pastclim_overview.Rmd
index 1e7453f9..b8cb8247 100644
--- a/vignettes/a0_pastclim_overview.Rmd
+++ b/vignettes/a0_pastclim_overview.Rmd
@@ -161,6 +161,13 @@ and the available time steps can be obtained with:
 get_time_bp_steps(dataset = "Example")
 ```
 
+We can also query the resolution of this dataset:
+```{r}
+get_resolution(dataset = "Example")
+```
+
+so, the *Example" dataset only has a resolution of 1x1 degree.
+
 For *Beyer2020* and *Krapp2021*, you can get a list of available
 variables for each dataset with: