Introduction
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 that can be opened by Google Earth(TM), 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:
- A search based on pattern matching the station name
- A search based on pattern matching the network ID
- A search based on region
- A search based on the vicinity of a given location
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.
Ignoring datatypes
The following examples detail how to use the cf_find_station search function ignoring any datatypes.
Station name search
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")
## name network agent start end open
## 1) Takaka, Kotinga Road F02882 3788 1970-08-01 2018-07-25 TRUE
## 2) Takaka Pohara F02884 3790 1986-07-01 2018-07-25 TRUE
## 3) Upper Takaka 2 F12083 11519 1995-07-12 2018-07-25 TRUE
## 4) Takaka Ews F02885 23849 2002-04-30 2018-07-25 TRUE
## 5) Takaka Aero Raws O00957 41196 2015-08-12 2018-07-25 TRUE
## 6) Takaka, Kotinga 2 F02883 3789 1985-11-30 2012-07-01 FALSE
## 7) Upper Takaka F12082 7316 1991-10-31 1992-10-31 FALSE
## 8) Takaka,Patons Rock F02772 3779 1969-10-01 1975-01-01 FALSE
## 9) Takaka,Kotinga 1 F02971 3794 1961-12-01 1971-08-01 FALSE
## 10) Takaka Aero F02871 3785 1936-11-01 1970-04-01 FALSE
## 11) Takaka Hill F12081 3833 1947-09-01 1959-11-01 FALSE
## 12) Takaka,Bu Bu F02872 3786 1933-04-01 1945-11-30 FALSE
## 13) Takaka F02881 3787 1904-01-01 1927-10-01 FALSE
## distance lat lon
## 1) 0 -40.87200 172.8090
## 2) 0 -40.84500 172.8670
## 3) 0 -41.01516 172.8258
## 4) 0 -40.86364 172.8057
## 5) 0 -40.81531 172.7765
## 6) 0 -40.88200 172.8010
## 7) 0 -41.05100 172.8330
## 8) 0 -40.78900 172.7570
## 9) 0 -40.90000 172.7750
## 10) 0 -40.81600 172.7720
## 11) 0 -41.01700 172.8670
## 12) 0 -40.85000 172.7330
## 13) 0 -40.81700 172.8000
This shows that 8 of these 13 stations are closed. The search in clifro does not ignore the station status.
cf_find_station("takaka", status = "open")
## name network agent start end open distance
## 1) Takaka, Kotinga Road F02882 3788 1970-08-01 2018-07-25 TRUE 0
## 2) Takaka Pohara F02884 3790 1986-07-01 2018-07-25 TRUE 0
## 3) Upper Takaka 2 F12083 11519 1995-07-12 2018-07-25 TRUE 0
## 4) Takaka Ews F02885 23849 2002-04-30 2018-07-25 TRUE 0
## 5) Takaka Aero Raws O00957 41196 2015-08-12 2018-07-25 TRUE 0
## lat lon
## 1) -40.87200 172.8090
## 2) -40.84500 172.8670
## 3) -41.01516 172.8258
## 4) -40.86364 172.8057
## 5) -40.81531 172.7765
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.
Station network ID search
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")
## name network agent start end open
## 1) Takaka, Kotinga Road F02882 3788 1970-08-01 2018-07-25 TRUE
## 2) Takaka Pohara F02884 3790 1986-07-01 2018-07-25 TRUE
## 3) Takaka Ews F02885 23849 2002-04-30 2018-07-25 TRUE
## 4) Takaka, Kotinga 2 F02883 3789 1985-11-30 2012-07-01 FALSE
## 5) Nelson,Mckay Hut F02821 3780 1983-04-01 1993-08-16 FALSE
## 6) Gouland Downs F02831 3781 1984-10-31 1993-08-16 FALSE
## 7) Golden Bay,Table Hl I F02852 3783 1977-06-01 1991-11-23 FALSE
## 8) Golden Bay,Table Hl 2 F02853 3784 1977-06-01 1991-11-23 FALSE
## 9) Tarakohe F02891 3791 1932-05-01 1989-01-01 FALSE
## 10) Takaka Aero F02871 3785 1936-11-01 1970-04-01 FALSE
## 11) Totaranui F02892 3792 1957-01-01 1960-08-31 FALSE
## 12) Takaka,Bu Bu F02872 3786 1933-04-01 1945-11-30 FALSE
## 13) Takaka F02881 3787 1904-01-01 1927-10-01 FALSE
## 14) Quartz Ranges F02851 3782 1901-01-01 1902-08-31 FALSE
## distance lat lon
## 1) 0 -40.87200 172.8090
## 2) 0 -40.84500 172.8670
## 3) 0 -40.86364 172.8057
## 4) 0 -40.88200 172.8010
## 5) 0 -40.89000 172.2130
## 6) 0 -40.89200 172.3510
## 7) 0 -40.80700 172.5560
## 8) 0 -40.80700 172.5560
## 9) 0 -40.82500 172.8980
## 10) 0 -40.81600 172.7720
## 11) 0 -40.82300 173.0020
## 12) 0 -40.85000 172.7330
## 13) 0 -40.81700 172.8000
## 14) 0 -40.86700 172.5170
Notice that the resulting dataframes in all of these searches are first ordered by the date they last received data then by the date they opened to give the longest-running open stations first and the most historic, closed stations last.
Return all stations within a region
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.
# 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 253 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.
Return all stations within the vicinity of a given location
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.st = cf_find_station(lat = -40.85, long = 172.8, rad = 10, search = "latlong")
takaka.town.st[, -c(8, 9)]
## name network agent start end open distance
## 1 Takaka, Kotinga Road F02882 3788 1970-08-01 2018-07-26 TRUE 2.6
## 2 Takaka Pohara F02884 3790 1986-07-01 2018-07-26 TRUE 5.7
## 3 Takaka Ews F02885 23849 2002-04-30 2018-07-26 TRUE 1.6
## 4 Takaka Aero Raws O00957 41196 2015-08-12 2018-07-26 TRUE 4.3
# We may rather order the stations by distance from the township
takaka.town.st[order(takaka.town.st$distance), -c(8, 9)]
## name network agent start end open distance
## 3 Takaka Ews F02885 23849 2002-04-30 2018-07-26 TRUE 1.6
## 1 Takaka, Kotinga Road F02882 3788 1970-08-01 2018-07-26 TRUE 2.6
## 4 Takaka Aero Raws O00957 41196 2015-08-12 2018-07-26 TRUE 4.3
## 2 Takaka Pohara F02884 3790 1986-07-01 2018-07-26 TRUE 5.7
Searches based on datatypes
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.
Note
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.
# Create a clifro datatype for hourly rain
hourly.rain.dt = cf_datatype(3, 1, 2)
hourly.rain.dt
## dt.name dt.type dt.options dt.combo
## dt1 Precipitation Rain (fixed periods) [Hourly]
# 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 2018-07-19 TRUE 0
This tells us that the only open station in Takaka where hourly rain data is available is at the Takaka Ews station.
More than one search at a time
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 cfDatatypes (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.
my.composite.search = takaka.town.st + cf_find_station("kaitaia",
search = "region",
datatype = hourly.rain.dt)
my.composite.search
## name network agent start end open
## 1) Takaka, Kotinga Road F02882 3788 1970-08-01 2018-07-26 TRUE
## 2) Takaka Pohara F02884 3790 1986-07-01 2018-07-26 TRUE
## 3) Takaka Ews F02885 23849 2002-04-30 2018-07-26 TRUE
## 4) Takaka Aero Raws O00957 41196 2015-08-12 2018-07-26 TRUE
## 5) Kaitaia Aero Ews A53026 18183 2000-06-15 2018-07-24 TRUE
## 6) Trounson Cws A53762 37131 2009-06-04 2018-07-24 TRUE
## 7) Russell Cws A54212 41262 2016-04-05 2018-07-24 TRUE
## 8) Kaikohe Aws A53487 1134 1985-11-14 2018-07-23 TRUE
## 9) Purerua Aws A54101 1196 1995-01-01 2018-07-23 TRUE
## 10) Cape Reinga Aws A42462 1002 1995-01-01 2018-07-23 TRUE
## 11) Kerikeri Aerodrome Aws A53295 37258 2008-06-26 2018-07-23 TRUE
## 12) Kerikeri Ews A53191 1056 2002-06-28 2018-07-19 TRUE
## 13) Dargaville 2 Ews A53987 25119 2003-10-30 2018-07-19 TRUE
## 14) Kaitaia Ews A53127 17067 1998-12-17 2018-07-12 TRUE
## distance lat lon
## 1) 2.6 -40.87200 172.8090
## 2) 5.7 -40.84500 172.8670
## 3) 1.6 -40.86364 172.8057
## 4) 4.3 -40.81531 172.7765
## 5) 0.0 -35.06770 173.2874
## 6) 0.0 -35.72035 173.6515
## 7) 0.0 -35.26835 174.1360
## 8) 0.0 -35.41720 173.8229
## 9) 0.0 -35.12900 174.0150
## 10) 0.0 -34.42963 172.6819
## 11) 0.0 -35.26200 173.9110
## 12) 0.0 -35.18300 173.9260
## 13) 0.0 -35.93145 173.8532
## 14) 0.0 -35.13500 173.2620
# How long have these stations been open for?
transform(my.composite.search, ndays = round(end - start))[, c(1, 10)]
## name ndays
## 1 Takaka, Kotinga Road 17526 days
## 2 Takaka Pohara 11713 days
## 3 Takaka Ews 5931 days
## 4 Takaka Aero Raws 1079 days
## 5 Kaitaia Aero Ews 6613 days
## 6 Trounson Cws 3337 days
## 7 Russell Cws 840 days
## 8 Kaikohe Aws 11939 days
## 9 Purerua Aws 8604 days
## 10 Cape Reinga Aws 8604 days
## 11 Kerikeri Aerodrome Aws 3679 days
## 12 Kerikeri Ews 5865 days
## 13 Dargaville 2 Ews 5376 days
## 14 Kaitaia Ews 7147 days
So where are these stations?
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 all the 698 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.
