initial commit v1.0

R-Code/newsfokus-functions.R

@@ -0,0 +1,127 @@
+require(stringr)
+require(RCurl)
+
+
+dlParsePage <- function(url, dest) {
+  if (!file.exists(dest)) {
+    url_curl <- getURL(url, curl=handle)
+    write(url_curl, dest)
+  }
+  parsed <- htmlParse(dest, encoding = "UTF-8")
+  return(parsed)
+}
+
+# Calculate the number of days in a specific month
+  # (Important for manipulating the search URL because otherwise there would be articles 
+  # of the NEXT month in the search results if we have a too large time span)
+getDays <- function(i, df) {
+  cur_tspan <- names(df)[i]
+  cur_m <- as.numeric(str_extract(cur_tspan, "^\\d+\\>"))
+  cur_y <- as.numeric(str_extract(cur_tspan, "\\d{4}"))
+  if (cur_m == 12) {
+    nex_y <- cur_y + 1
+    nex_m <- 1
+  }
+  else {
+    nex_y <- cur_y
+    nex_m <- cur_m +1
+  }
+  cur_date <- str_c(cur_y, cur_m, "01", sep = "-")
+  nex_date <- str_c(nex_y, nex_m, "01", sep = "-")
+  days <- as.numeric(difftime(as.Date(nex_date), as.Date(cur_date)))
+  return(days)
+}
+
+getCode <- function(i, df) {
+  # There's a bug with appearances of Namibia, producing NAs instead of "NA"
+  if (! is.na(as.character(df[i]))) { 
+    code <- as.character(df[i])  # Get the country's code
+  }
+  else {
+    code <- "NA"
+  }
+  return(code)
+}
+
+# NAs get converted into "NA" for Namibia
+namibiaBug <- function(x) {
+  if (is.na(x)) {x <- "NA"}
+  return(x)
+}
+
+
+# Get all headlines for a specific country and a specific month
+getHeadlines <- function(df, countrycol, descountry, month) {
+  no <- 0
+  news <- NULL
+  for (r in 1:nrow(df)) {
+    descountry <- namibiaBug(descountry)
+    curcountry <- namibiaBug(as.character(df[r,countrycol]))
+    if (curcountry == descountry) {
+      no <- no + 1
+      news[no] <- as.character(df[r,month])
+    }
+  }
+  cat(news)
+}
+
+
+# Remove months with 0 surprising newsfocuses
+removeZeroMonths <- function(df, mincol, maxcol) {
+  delmonthno <- 0
+  delmonth <- NULL
+  for (c in mincol:maxcol) {
+    month <- names(df)[c]
+    no <- 0
+    for (r in 1:nrow(df)) {
+      no <- no + as.numeric(df[r,c])
+    }
+    if (no == 0) {
+      delmonthno <- delmonthno + 1
+      delmonth[delmonthno] <- month
+    }
+  }
+  return(df [! names(df) %in% delmonth])
+}
+
+# Get countries which produced newsfocuses in a given month
+getFocusCountries <- function(df, month) {
+exists <- FALSE
+for (c in 1:ncol(df)) {
+  status <- str_detect(month, names(df)[c])
+  if (status) {
+    exists <- TRUE
+  }
+}
+if (!exists) {
+  return(cat(month, "isn't a valid column in given dataframe"))
+}
+no <- 0
+countries <- NULL
+  for (r in 1:nrow(df)) {
+    supfoc <- df[r,month]
+    if (supfoc > 0) {
+      no <- no + 1
+      countries[no] <- as.character(df[r,"name"])
+    }
+  }
+  return(countries)
+}
+
+# Get average development of news over a span of years
+getAverages <- function(df, codecol, code, yearspan) {
+  no <- 0
+  averg <- NULL
+  for (r in 1:nrow(df)) {
+    code <- namibiaBug(code)
+    curcode <- namibiaBug(df[r,codecol])
+    if (curcode == code) {
+      for (y in yearspan) {
+        no <- no + 1
+        curcol <- str_c(y,"-averg")
+        averg[no] <- as.numeric(df[r,curcol])
+      }
+    }
+  }
+  return(data.frame(year=yearspan, averg=averg))
+}