paste doesn't recognize object - r

Question

I'm trying to run this function, but when I try to compile it, it says:
Error in paste("http://uk.advfn.com/p.php?pid=financials&symbol=", Symbol, :
object 'Symbol' not found
fund.data <- function
(
Symbol, # ticker
n=10, # number of periods
mode=c('quarterly','annual'), # periodicity
max.attempts=5 # maximum number of attempts to download before exiting
)
dirname(sys.frame(1)$ofile)
{
all.data = c()
option.value = -1
start_date = c('istart_date,start_date')
names(start_date) = c('quarterly,annual')
repeat {
# download Quarterly Financial Report data
if(option.value >= 0) {
url = paste('http://uk.advfn.com/p.php?pid=financials&symbol=', Symbol, '&btn=', mode[1], '_reports&', start_date[mode[1]], '=', option.value, sep = '')
} else {
url = paste('http://uk.advfn.com/p.php?pid=financials&symbol=', Symbol, '&btn=', mode[1], '_reports', sep = '')
}
cat('Downloading', url, '\n')
#txt = join(readLines(url))
for(iattempt in 1:max.attempts) {
flag = T
tryCatch({
txt = join(readLines(url))
}, interrupt = function(ex) {
flag <<- F
Sys.sleep(0.1)
}, error = function(ex) {
flag <<- F
Sys.sleep(0.1)
}, finally = {
if(flag) break
})
}
if( length(grep('INDICATORS', txt, ignore.case = T)) == 0 ) {
cat('No Data Found for', Symbol, '\n')
return(all.data)
}
# get title
pos = regexpr(pattern = '<title>(.*?)</title>', txt, ignore.case = TRUE, perl = TRUE)
if(length(pos) == 1)
title = substr(txt, attr(pos, 'capture.start'), attr(pos, 'capture.start') + attr(pos, 'capture.length') - 1)
# extract table from this page
data = extract.table.from.webpage(txt, 'INDICATORS', has.header = T)
colnames(data) = data[1,]
rownames(data) = data[,1]
data = data[,-1,drop=F]
# only add not already present data
add.index = which( is.na(match( colnames(data), colnames(all.data) )) )
all.data = cbind(data[,add.index,drop=F], all.data)
# check if it is time to stop
if(ncol(all.data) >= n) break
if(option.value == 0) break
# extract option value to go to the next page
temp = gsub(pattern = '<option', replacement = '<tr>', txt, perl = TRUE)
temp = gsub(pattern = '</option>', replacement = '</tr>', temp, perl = TRUE)
temp = extract.table.from.webpage(temp, 'All amounts', has.header = T)
temp = apply(temp,1,join)
index.selected = grep('selected', temp)
option.value = 0
if( length(index.selected) )
option.value = as.double( gsub('.*value=\'([0-9]*).*', '\\1', temp[index.selected]) )
if(option.value > 0) {
# can only get 5 time periods at a time
option.value = option.value - 5
option.value = max(0, option.value)
} else {
break
}
}
# remove empty columns
all.data = all.data[, colSums(nchar(trim(all.data))) > 0, drop=F]
all.data = rbind(all.data, title)
rownames(all.data)[nrow(all.data)] = 'HTMLTITLEtext'
if( ncol(all.data) > n ) {
return(all.data[,(ncol(all.data)-n+1):ncol(all.data), drop=F])
} else {
return(all.data)
}
}

Answer 1

The way you've written your code, your dirname() call comprises the entirety of the body of your function. The braced block that follows is executed immediately and is not part of the function.
After running all your code (and getting the error you quoted), this is fund.data():
fund.data;
## function
## (
## Symbol, # ticker
## n=10, # number of periods
## mode=c('quarterly','annual'), # periodicity
## max.attempts=5 # maximum number of attempts to download before exiting
## )
## dirname(sys.frame(1)$ofile)
As you can see, the braced block was not taken as part of the function definition. It was executed by itself immediately after fund.data() was defined. A function definition takes only the immediately following expression as the body, although that expression may comprise a braced block, which allows any number of statements to be subsumed within it. And as #RichardScriven pointed out in his comment, there is no actual call to your function anywhere in your code.
So, the reason why you're getting the exact error "object 'Symbol' not found" is because the function parameter Symbol does not exist in your braced block, because it is not part of the body of your function and was executed by itself.
To solve your problem, you need to surround the entire function body with a braced block:
fund.data <- function
(
Symbol, # ticker
n=10, # number of periods
mode=c('quarterly','annual'), # periodicity
max.attempts=5 # maximum number of attempts to download before exiting
) {
dirname(sys.frame(1)$ofile)
all.data = c()
option.value = -1
...
}
Although it's not clear what the purpose of the dirname() call is, since its return value is not used.