added load_dataset function

ext/SpectralIndicesDataFramesExt.jl

@@ -54,7 +54,7 @@ function SpectralIndices.RBF(params::DataFrame)
     return result_df
 end
 
-function open_dataset(dataset::String)
+function SpectralIndices.load_dataset(dataset::String)
     datasets = Dict("sentinel" => "S2_10m.json", "spectral" => "spectral.json")
 
     if dataset in keys(datasets)

ext/SpectralIndicesYAXArraysExt.jl

@@ -89,4 +89,32 @@ function SpectralIndices.RBF(params::YAXArray)
     return result
 end
 
+function SpectralIndices.load_dataset(dataset::String)
+    datasets = Dict("sentinel" => "S2_10m.json", "spectral" => "spectral.json")
+
+    if dataset in keys(datasets)
+        nothing
+    else
+        error("Dataset name not valid. Datasets available: sentinel and spectral")
+    end
+
+    ds = SpectralIndices._load_json(datasets[dataset])
+
+    # Convert each vector of vectors in `ds` into a matrix
+    matrices = [hcat(ds[i]...) for i in 1:length(ds)]
+
+    # Stack these matrices to form a 3D array
+    data_3d = cat(matrices...; dims=3)
+
+    # Define dimensions
+    x_dim = Dim{:x}(1:300)
+    y_dim = Dim{:y}(1:300)
+    bands = Dim{:bands}(["B02", "B03", "B04", "B08"])
+
+    # Create the YAXArray
+    yax_ds = YAXArray((x_dim, y_dim, bands), data_3d)
+
+    return yax_ds
+end
+
 end #module

src/SpectralIndices.jl

@@ -22,7 +22,7 @@ indices = _create_indices()
 bands = _create_bands()
 constants = _create_constants()
 
-export get_datasets
+export get_datasets, load_dataset
 export SpectralIndex, indices, compute
 export PlatformBand, Band
 export Constant

src/datasets.jl

@@ -1,5 +1,26 @@
 """
-gets the indices from spyndex
+    get_datasets(; datasets=["S2_10m.json", "spectral.json"], data_loc=joinpath(dirname(@__FILE__), "..", "data"))
+
+Download predefined datasets from a specified remote location and save them to a local directory.
+
+# Keyword Arguments
+
+  - `datasets::Array{String,1}`: A list of dataset filenames to download. Defaults to `["S2_10m.json", "spectral.json"]`.
+  - `data_loc::String`: The local directory path where the downloaded datasets will be saved. Defaults to a `data` directory located one level up from the script's directory.
+
+# Description
+
+This function iterates over a list of dataset filenames, downloads each dataset from a predefined remote URL, and saves them into a specified local directory. The remote URL is currently hardcoded to download specifically the "S2_10m.json" file for any given dataset in the list. Adjust the function or its usage accordingly if different URLs are needed for different datasets.
+
+# Example
+
+```julia
+get_datasets()  # Downloads the default datasets to the default location
+
+get_datasets(; datasets=["custom_dataset.json"], data_loc="path/to/custom/directory")
+```
+
+This is particularly useful for setting up local environments with necessary data files for further processing or analysis.
 """
 function get_datasets(;
     datasets=["S2_10m.json", "spectral.json"],
@@ -8,15 +29,46 @@ function get_datasets(;
     for ds in datasets
         file_dest = joinpath(data_loc, ds)
         Downloads.download(
-            "https://raw.githubusercontent.com/awesome-spectral-indices/spyndex/main/spyndex/data/S2_10m.json",
+            "https://raw.githubusercontent.com/awesome-spectral-indices/spyndex/main/spyndex/data/" *
+            ds,
             file_dest,
         )
     end
 end
 
 """
+    load_dataset(dataset::String) -> YAXArray
+    load_dataset(dataset::String) -> DataFrame
+
+Load a specified dataset and convert it into either a YAXArray or a DataFrame, depending on the loaded packages.
+
+# Arguments
+
+  - `dataset::String`: The name of the dataset to load. Currently supports `"sentinel"` and `"spectral"`.
+
+# Returns
+
+  - If YAXArrays is loaded in the namespace, returns a `YAXArray` object containing the loaded dataset, with dimensions labeled as `:x`, `:y`, and `:bands`. The spatial dimensions (`:x` and `:y`) are assumed to have a size of 300 each, and the `:bands` dimension includes ["B02", "B03", "B04", "B08"] bands.
+  - If DataFrames is loaded in the namespace, returns a `DataFrame` with the dataset loaded into it.
+
+# Errors
+
+Throws an error if the `dataset` argument does not match one of the predefined dataset names.
+
+# Example
+
+```julia
+# Load dataset as YAXArray
+yax_ds = SpectralIndices.load_dataset("sentinel")
+
+# Load dataset as DataFrame
+df_ds = SpectralIndices.load_dataset("spectral")
+```
+
+The current implementation expects the JSON files ("S2_10m.json" for "sentinel" and "spectral.json" for "spectral") to follow a specific format: a vector of vectors where each inner vector represents a band's data in a 300x300 spatial grid for the YAXArray version, or a suitable structure that can be directly converted into a DataFrame for the DataFrame version.
+The files are already provided for examples in the package in the folder `data`.
 """
-function open_dataset()
+function load_dataset()
     dfext = Base.get_extension(SpectralIndices, :SpectralIndicesDataFramesExt)
     yaxaxext = Base.get_extension(SpectralIndices, :SpectralIndicesYAXArraysExt)
 

test/utils.jl

@@ -31,7 +31,7 @@ end
 @testset "Download Datasets Test" begin
     temp_dir = mktempdir() # Temporary directory for testing
     try
-        expected_files = ["test_S2_10m.json", "test_spectral.json"]
+        expected_files = ["S2_10m.json", "spectral.json"]
         get_datasets(; datasets=expected_files, data_loc=temp_dir)
         for expected_file in expected_files
             @test isfile(joinpath(temp_dir, expected_file))