3 Importing the ESMA data into R

3.1 Wrap the import operation in one R function

The .csv files containing the lists of financial products identifiers (ISIN numbers) are released by the European Securities and Markets Authority

Set directory:

setwd("filepath/example")

x = the .csv file name, for ex.: nonequity_si_calculations_-_publication_file 15-10-18 - SI calculations.csv

import_SI.csv <- function(x)
{

Import .csv from directory, set up column names and classes, set decimal sign to “.”

 SI_import <- read.csv(x, header = TRUE, dec = ".", 
                        col.names = c("From", "To", "ISIN", "Transactions", "Turnover"), 
                        colClasses = c("character", "character", "character", "character", "character"))                          

Change the format of col. “From” and “To” into date

SI_import$From <- as.Date(SI_import$From, format = "%m/%d/%Y")
SI_import$To <- as.Date(SI_import$To, format = "%m/%d/%Y")

Remove “,” after thousands

SI_import$Transactions <- gsub(",","", SI_import$Transactions)
SI_import$Turnover <- gsub(",","", SI_import$Turnover)

Change col. Transactions and Turnover into numeric

SI_import$Transactions <- as.numeric(SI_import$Transactions)
SI_import$Turnover <- as.numeric(SI_import$Turnover)

Replace zero’s by NA’s

SI_import[SI_import == 0] <- NA 

Return the table SI_import

return(SI_import)
}