ch_get_url_data: Gets remote data sets

In CSHShydRology: Canadian Hydrological Analyses

Gets remote data sets

Description

Accesses data sets, via a url the first time, saves them locally, then accesses them locally after the first time the script is executed.

Usage

ch_get_url_data(gd_url, gd_filename, stop_on_error = TRUE)

Arguments

gd_url	url for accessing data set
gd_filename	name of file on local drive, including full path
stop_on_error	Optional. If there is an error in accessing the file and stop_on_error = TRUE (the default) error/warning messages cause a stop. If stop_on_error = FALSE, then the error message string is returned.

Value

Returns a data frame (from a .csv file), a raster object (from a .tif file), or an sf object (from a GeoJSON file).

Author(s)

Dan Moore Kevin Shook

Examples

# Example not tested automatically as multiple large data files are downloaded which is slow

# Tested using files in the Upper Penticton Creek
# zenodo repository https://zenodo.org/record/4781469
library(ggplot2)
library(raster)

# create directory to store data sets
dir_name <- tempdir(check = FALSE)
if (!dir.exists(dir_name))
  dir.create(dir_name)
 
# test with soil moisture data in csv format
sm_fn <- file.path(dir_name, "sm_data.csv")
sm_url <- "https://zenodo.org/record/4781469/files/sm_data.csv"
sm_data <- ch_get_url_data(sm_url, sm_fn, stop_on_error = FALSE)

if (typeof(sm_data) != "character") {
  head(sm_data)
} else {
  message(sm_data)
}
# test with tif/tiff file containing a dem
ra_fn <- file.path(dir_name, "gs_dem25.tif")
ra_url <- "https://zenodo.org/record/4781469/files/gs_dem25.tif"
ra_data <- ch_get_url_data(ra_url, ra_fn, stop_on_error = FALSE)

if (typeof(ra_data) != "character") {
  plot(ra_data)
} else {
  message(sm_data)}
 
# test with GeoJSON
gs_fn <- file.path(dir_name, "gs_soilmaps.GeoJSON")
gs_url <- "https://zenodo.org/record/4781469/files/gs_soilmaps.GeoJSON"
gs_data <- ch_get_url_data(gs_url, gs_fn, stop_on_error = FALSE)
if (typeof(gs_data) != "character") {
  ggplot(gs_data) +
  geom_sf(aes(fill = new_key)) +
  labs(fill = "Soil class",
       x = "UTM Easting (m)",
       y = "UTM Northing (m)") +
  coord_sf(datum = 32611) +
  theme_bw()
 } else {
 print(gs_data)}

CSHShydRology documentation built on Feb. 4, 2026, 5:06 p.m.