tasks a-s

Task/SEDOLs/R/sedols.r

@@ -0,0 +1,37 @@
+# Read in data from text connection
+datalines <- readLines(tc <- textConnection("710889
+B0YBKJ
+406566
+B0YBLH
+228276
+B0YBKL
+557910
+B0YBKR
+585284
+B0YBKT")); close(tc)
+
+# Check data valid
+checkSedol <- function(datalines)
+{
+   ok <- grep("^[[:digit:][:upper:]]{6}$", datalines)
+   if(length(ok) < length(datalines))
+   {
+      stop("there are invalid lines")
+   }
+}
+checkSedol(datalines)
+
+# Append check digit
+appendCheckDigit <- function(x)
+{
+   if(length(x) > 1) return(sapply(x, appendCheckDigit))
+   ascii <- as.integer(charToRaw(x))
+   scores <- ifelse(ascii < 65, ascii - 48, ascii - 55)
+   weights <- c(1, 3, 1, 7, 3, 9)
+   chkdig <- (10 - sum(scores * weights) %% 10) %% 10
+   paste(x, as.character(chkdig), sep="")
+}
+withchkdig <- appendCheckDigit(datalines)
+
+#Print in format requested
+writeLines(withchkdig)