library(clifro)
Choosing clifro
stations is made easy with the single cf_find_station
function. This function is all that is required to find clifro
stations. This
function is equivalent to conducting the same search on the
find stations page when
conducting a query online at CliFlo, except without some of the errors and bugs.
This means that the searches and the types of searches possible are exactly the
same however, clifro
extends functionality to exploring the spatial nature of
stations via KML files, or plotting
directly in R. This is the main advantage in searching for stations using
clifro
as locating suitable stations on a map is generally the preferred
search tool.
There are four possible types of searches:
For each of these searches either all, open or closed stations may be returned
and these searches also may only return stations where given datatypes are
available. The primary goal in searching for stations is to find the
unique station agent number required to create a cfStation
object. This
vignette details the various search options in clifro
and ways to find these
requisite agent numbers, primarily by way of example.
The following examples detail how to use the cf_find_station
search function
ignoring any datatypes.
Both of these searches use pattern matching to find the appropriate stations. The station name search is useful for searching stations in certain towns or suburbs or maybe even streets and parks. The network ID is a number that is assigned to the stations which makes this search useful to look up stations where these are known.
These searches are used when part or all of the station name or network ID is
known. For example, consider we are looking for open stations located in Takaka,
at the southeastern end of Golden Bay at the northern end of the South Island,
New Zealand. The default for the cf_find_station
function is to search open
station names matching the string.
At the time of writing this, CliFlo ignores the status argument in the name and
network ID search whereas clifro
does not. Searching open stations with the
station name matching "takaka" on CliFlo will return these stations.
# Equivalent to searching for status = "open" on CliFro # Note the search string is not case sensitive cf_find_station("takaka", status = "all")
takaka.df = structure(list(name = c("Takaka, Kotinga Road", "Riwaka At Takaka Hill", "Takaka Pohara", "Takaka At Harwoods", "Takaka At Kotinga", "Takaka @ Canaan", "Upper Takaka 2", "Takaka Ews", "Takaka Aero Raws", "Takaka, Kotinga 2", "Upper Takaka", "Takaka,Patons Rock", "Takaka,Kotinga 1", "Takaka Aero", "Takaka Hill", "Takaka,Bu Bu", "Takaka"), network = c("F02882", "O12090", "F02884", "F15292", "F15291", "F0299A", "F12083", "F02885", "O00957", "F02883", "F12082", "F02772", "F02971", "F02871", "F12081", "F02872", "F02881"), agent = c(3788L, 44046L, 3790L, 44050L, 44051L, 44072L, 11519L, 23849L, 41196L, 3789L, 7316L, 3779L, 3794L, 3785L, 3833L, 3786L, 3787L), start = structure(c(18273600, 316263600, 520516800, 570020400, 704030400, 760014000, 805464000, 1020081600, 1439294400, 502110000, 688820400, -7992000, -255182400, -1046692800, -704894400, -1159875000, -2082886200), class = c("POSIXct", "POSIXt"), tzone = "NZ"), end = structure(c(1597665600, 1597665600, 1597665600, 1597665600, 1597665600, 1597665600, 1597665600, 1597665600, 1597665600, 1341057600, 720442800, 157719600, 49809600, 7732800, -320932800, -760190400, -1333452600), class = c("POSIXct", "POSIXt" ), tzone = "NZ"), open = c(TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE), distance = c(NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA), lat = c(-40.872, -41.03192, -40.845, -41.03094, -40.87068, -40.93987, -41.01516, -40.86364, -40.81531, -40.882, -41.051, -40.789, -40.9, -40.816, -41.017, -40.85, -40.817 ), lon = c(172.809, 172.84439, 172.867, 172.79802, 172.808, 172.90821, 172.82582, 172.80568, 172.7765, 172.801, 172.833, 172.757, 172.775, 172.772, 172.867, 172.733, 172.8)), class = "data.frame", row.names = c(NA, -17L)) new("cfStation", takaka.df)
This shows that 8 of these 17 stations are closed. The search in clifro
does
not ignore the station status.
cf_find_station("takaka", status = "open")
takaka.df = structure(list(name = c("Takaka, Kotinga Road", "Riwaka At Takaka Hill", "Takaka Pohara", "Takaka At Harwoods", "Takaka At Kotinga", "Takaka @ Canaan", "Upper Takaka 2", "Takaka Ews", "Takaka Aero Raws"), network = c("F02882", "O12090", "F02884", "F15292", "F15291", "F0299A", "F12083", "F02885", "O00957"), agent = c(3788L, 44046L, 3790L, 44050L, 44051L, 44072L, 11519L, 23849L, 41196L), start = structure(c(18273600, 316263600, 520516800, 570020400, 704030400, 760014000, 805464000, 1020081600, 1439294400), class = c("POSIXct", "POSIXt"), tzone = "NZ"), end = structure(c(1597665600, 1597665600, 1597665600, 1597665600, 1597665600, 1597665600, 1597665600, 1597665600, 1597665600), class = c("POSIXct", "POSIXt"), tzone = "NZ"), open = c(TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE), distance = c(NA, NA, NA, NA, NA, NA, NA, NA, NA), lat = c(-40.872, -41.03192, -40.845, -41.03094, -40.87068, -40.93987, -41.01516, -40.86364, -40.81531), lon = c(172.809, 172.84439, 172.867, 172.79802, 172.808, 172.90821, 172.82582, 172.80568, 172.7765)), class = "data.frame", row.names = c(NA, -9L)) new("cfStation", takaka.df)
Stations are considered open in clifro
if the final date returned from the
search is within four weeks of the current date. This gives the user a better
idea on the stations that are currently collecting data.
The same can be done for searching stations using network ID although
search = "network"
needs to be added to the function call. Assume we knew
that the only stations we were interested in were the open stations whose
network ID's match F028
.
cf_find_station("f028", search = "network", status = "all")
xx.df = structure(list(name = c("Takaka, Kotinga Road", "Takaka Pohara", "Takaka Ews", "Aorere At Salisbury Bridge", "Takaka, Kotinga 2", "Nelson,Mckay Hut", "Gouland Downs", "Golden Bay,Table Hl I", "Golden Bay,Table Hl 2", "Tarakohe", "Takaka Aero", "Totaranui", "Takaka,Bu Bu", "Takaka", "Quartz Ranges"), network = c("F02882", "F02884", "F02885", "F02854", "F02883", "F02821", "F02831", "F02852", "F02853", "F02891", "F02871", "F02892", "F02872", "F02881", "F02851" ), agent = c(3788L, 3790L, 23849L, 44020L, 3789L, 3780L, 3781L, 3783L, 3784L, 3791L, 3785L, 3792L, 3786L, 3787L, 3782L), start = structure(c(18273600, 520516800, 1020081600, 1311595200, 502110000, 417960000, 467982000, 233928000, 233928000, -1188819000, -1046692800, -410270400, -1159875000, -2082886200, -2177494200), class = c("POSIXct", "POSIXt"), tzone = "NZ"), end = structure(c(1597665600, 1597665600, 1597665600, 1597665600, 1341057600, 745416000, 745416000, 690807600, 690807600, 599569200, 7732800, -294667200, -760190400, -1333452600, -2125049400 ), class = c("POSIXct", "POSIXt"), tzone = "NZ"), open = c(TRUE, TRUE, TRUE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE), distance = c(NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA), lat = c(-40.872, -40.845, -40.86364, -40.80236, -40.882, -40.89, -40.892, -40.807, -40.807, -40.825, -40.816, -40.823, -40.85, -40.817, -40.867), lon = c(172.809, 172.867, 172.80568, 172.53328, 172.801, 172.213, 172.351, 172.556, 172.556, 172.898, 172.772, 173.002, 172.733, 172.8, 172.517)), class = "data.frame", row.names = c(NA, -15L)) new("cfStation", xx.df)
Notice that the resulting dataframes in all of these searches are first ordered by the date they last received data, and then by the date they opened, to return the longest-running open stations first and the most historic, closed stations last.
This broad search returns all, open or closed stations within one of the 29
preselected New Zealand regions (note that stations can belong to more than
one region). The search = "region"
argument must be
added to the cf_find_station
function to conduct these searches. If the region
is unknown then the search argument may be missing which brings up an
interactive menu of the 29 regions for the user to select
(cf_find_station(search = "region")
), otherwise partial matching is used.
open.queenstown.stations.df = dget(system.file("extdata", "queenStations", package = "clifro")) open.queenstown.stations = new("cfStation", open.queenstown.stations.df)
# Partial match for the Queenstown region open.queenstown.stations = cf_find_station("queen", search = "region")
Typing open.queenstown.stations
into R will then return all the
r nrow(open.queenstown.stations)
open Queenstown stations. This
is clearly a burden to choose stations based on a large list of numbers hence
plotting them on a map (covered below) to assess their spatial extent will make
this task much easier.
This location based search is conducted by including the
search = "latlong"
argument to the cf_find_station
function. There are
three parameters needed for this search; latitude, longitude and radius
(kilometres). Just like any other function in R, if these arguments aren't
named then the order matters and should be written in the order specified above.
The latitude and longitude must be given in decimal degrees.
We are (still) interested in finding all open stations around the small town of Takaka. From GeoHack we can see that the latitude is -40.85 and the longitude is 172.8. We are interested in all open stations within a 10km radius of the main township.
takaka.town.df = structure(list(name = c("Takaka, Kotinga Road", "Takaka Pohara", "Anatoki At Happy Sams", "Takaka At Kotinga", "Takaka Ews", "Motupiko At Reillys Bridge", "Takaka Aero Raws"), network = c("F02882", "F02884", "F15293", "F15291", "F02885", "F1529M", "O00957"), agent = c(3788L, 3790L, 44015L, 44051L, 23849L, 44041L, 41196L), start = structure(c(18273600, 520516800, 657284400, 704030400, 1020081600, 1164711600, 1439294400 ), class = c("POSIXct", "POSIXt"), tzone = "NZ"), end = structure(c(1598788800, 1598788800, 1598788800, 1598788800, 1598788800, 1598788800, 1598788800 ), class = c("POSIXct", "POSIXt"), tzone = "NZ"), open = c(TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE), distance = c(2.6, 5.7, 5.8, 2.4, 1.6, 2.7, 4.3), lat = c(-40.872, -40.845, -40.88587, -40.87068, -40.86364, -40.85607, -40.81531), lon = c(172.809, 172.867, 172.74982, 172.808, 172.80568, 172.83162, 172.7765)), class = "data.frame", row.names = c(NA, -7L)) takaka.town.st = new("cfStation", takaka.town.df)
takaka.town.st = cf_find_station(lat = -40.85, long = 172.8, rad = 10, search = "latlong") # Print the result, but remove the lat and lon columns to fit the page takaka.town.st[, -c(8, 9)]
takaka.town.st[, -c(8, 9)] # We may rather order the stations by distance from the township takaka.town.st[order(takaka.town.st$distance), -c(8, 9)]
All the above searches did not include a datatype therefore they ignore the datatypes available at these stations. Imagine we are looking for hourly rain data at an open station in Takaka (using any of the aforementioned searches), we would need to include the hourly rain datatype in the search for it to return a suitable station.
Unless the Reefton EWS station is the only CliFlo station of interest, the user will need a CliFlo account to get data from other stations.
hourly.rain.dt = new("cfDatatype" , dt_name = "Precipitation" , dt_type = "Rain (fixed periods)" , dt_sel_option_names = list("Hourly") , dt_sel_combo_name = NA_character_ , dt_param = structure("ls_ra,1,2,3,4", .Names = "dt1") , dt_sel_option_params = list(structure("182", .Names = "prm2")) , dt_selected_options = list(2) , dt_option_length = 4 )
# Create a clifro datatype for hourly rain hourly.rain.dt = cf_datatype(3, 1, 2) hourly.rain.dt
hourly.rain.dt
# Conduct the search cf_find_station("takaka", datatype = hourly.rain.dt)
## name network agent start end open distance ## 1) Takaka Ews F02885 23849 2002-06-02 2020-08-16 TRUE NA
This tells us that the only open station in Takaka where hourly rain data is available is at the Takaka Ews station.
Since the cf_find_station
function returns cfStation
objects, any of these
methods work on objects created from the cf_station
function (see the
working with clifro stations vignette for more details). We can
conduct two or more searches at a time using the addition sign, just like we did
for cfDatatype
s (see the choose datatypes vignette).
We would like to return all open stations within a 10km radius of the Takaka township in the South Island, and the open stations in Kaitaia, in the North Island that collect hourly rain data.
kaitaia.df = structure(list(name = c("Kaitaia Aero Ews", "Trounson Cws", "Russell Cws", "Kaikohe Aws", "Purerua Aws", "Cape Reinga Aws", "Kerikeri Aerodrome Aws", "Kaitaia Ews", "Dargaville 2 Ews", "Kerikeri Ews"), network = c("A53026", "A53762", "A54212", "A53487", "A54101", "A42462", "A53295", "A53127", "A53987", "A53191"), agent = c(18183L, 37131L, 41262L, 1134L, 1196L, 1002L, 37258L, 17067L, 25119L, 1056L), start = structure(c(960984000, 1244030400, 1459771200, 500727600, 788871600, 788871600, 1214395200, 913806000, 1067425200, 1025179200), class = c("POSIXct", "POSIXt" ), tzone = "NZ"), end = structure(c(1598702400, 1598702400, 1598702400, 1598616000, 1598616000, 1598616000, 1598616000, 1598443200, 1598011200, 1597924800), class = c("POSIXct", "POSIXt"), tzone = "NZ"), open = c(TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE, TRUE), distance = c(NA, NA, NA, NA, NA, NA, NA, NA, NA, NA), lat = c(-35.0677, -35.72035, -35.26835, -35.4172, -35.129, -34.42963, -35.262, -35.13352, -35.93145, -35.183), lon = c(173.2874, 173.65153, 174.136, 173.8229, 174.015, 172.68186, 173.911, 173.26294, 173.85317, 173.926)), class = "data.frame", row.names = c(NA, -10L)) kaitaia.st = new("cfStation", kaitaia.df) my.composite.search = takaka.town.st + kaitaia.st
my.composite.search = takaka.town.st + cf_find_station("kaitaia", search = "region", datatype = hourly.rain.dt) my.composite.search
my.composite.search # How long have these stations been open for? transform(my.composite.search, ndays = round(end - start))[, c(1, 10)]
Up until now there probably hasn't been any good reason to choose clifro to search for stations instead of the 'Choose Stations' form on CliFlo. However, the real advantage of using clifro is to visualise the station locations on a map by returning a KML file, particularly when there are lots of stations returned by the search. This Keyhole Markup Language (KML) is an XML-based language provided by Google(TM) for defining the graphic display of spatial data in applications such as Google Earth(TM) and Google Maps(TM).
To return the stations as a KML file simply use the cf_save_kml
function on
any cfStation
object. The cf_find_station
function returns cfStation
objects therefore it's very easy to plot these on a map. To assess the
geographic extent of the Auckland stations we can return a KML file from the
search and open it using our preferred KML-friendly software.
# First, search for the stations all.auckland.st = cf_find_station("auckland", search = "region", status = "all")
Now all.auckland.st
contains the hundreds of Auckland stations where data have been recorded on CliFlo.
# Then save these as a KML cf_save_kml(all.auckland.st, file_name = "all_auckland_stations")
The green markers represent the open stations and the red markers indicate
closed stations. The resulting KML file is saved to the current R session's
working directory by default. Have a look at the
clifro station vignette for more methods and plotting of
cfStation
objects.
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