From 9a8ee0a153dfceda897bba47faa0643899b74e19 Mon Sep 17 00:00:00 2001
From: Olav Peeters <peeters@irceline.be>
Date: Mon, 9 Mar 2015 11:59:15 +0100
Subject: [PATCH] add demo correlation between two time series

---
 demo/00Index       |  1 +
 demo/correlation.R | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 demo/correlation.R

diff --git a/demo/00Index b/demo/00Index
index 3f4b946..9da8cbe 100644
--- a/demo/00Index
+++ b/demo/00Index
@@ -5,3 +5,4 @@ openair2            Openair pollution rose demo
 cache               How to manipulate the request cache
 spatial-coercion    Coercing selected classes to spatial classes
 distance-matrix     Find the five nearest stations
+correlation			Correlation between two timeseries
diff --git a/demo/correlation.R b/demo/correlation.R
new file mode 100644
index 0000000..abc09a9
--- /dev/null
+++ b/demo/correlation.R
@@ -0,0 +1,72 @@
+library(sensorweb4R)
+library(sp)
+library(lubridate)
+library(zoo)
+library(openair)
+
+# endpoint is rest-api of IRCEL
+endpoint <- example.endpoints()[2]
+
+# available services on this endpoint: only one
+srv <- services(endpoint)
+label(srv)
+
+## get the names of the phenonoma = pollutants
+phe <- phenomena(endpoint)
+head(label(phe))
+
+##get the names of the stations
+sta <- stations(srv)
+head(label(sta))
+
+# filter by category: e.g. only Black Carbon stations
+cat <- categories(srv)
+head(label(cat))
+sta <- stations(srv,category=cat[1])
+head(label(sta))
+
+# conversion info to dataframe, e.g.: as.data.frame()
+
+# get spatial info on stations
+geom <- sp::geometry(sta)
+head(geom)
+
+# get all timeseries in service
+# ts <- timeseries(srv)
+# or filter by station
+# ts <- timeseries(sta[1])
+# filter by category
+ts <- timeseries(endpoint, category=cat[1])[1:2]
+
+## available info on timeseries
+
+str(ts, max.level=2)
+ts <- fetch(ts)    # fetch info
+label(station(ts))
+label(category(ts))
+label(procedure(ts))
+
+
+#### download data
+
+# length of timeseries
+
+lubridate::duration(lubridate::new_interval(time(firstValue(ts)), time(lastValue(ts))))
+
+# filter: only a part of the series requested
+
+last <- min(time(lastValue(ts)))
+time <- lubridate::as.interval(lubridate::weeks(1), last-lubridate::weeks(1))
+
+data <- getData(ts,timespan=time)
+str(data)
+
+#### Create a scatterplot of two stations ##
+############################################
+
+BC <- as.data.frame(data)
+head(BC)
+class(BC$time2)
+names(BC) <- c("time",label(station(ts))[1],"time2",label(station(ts))[2])
+
+scatterPlot(BC, x=label(station(ts))[1], y=label(station(ts))[2],   linear=TRUE)
\ No newline at end of file