CODEWITHSUNDEEP
r
Harry Schaefer
Harry Schaefer

Reputation: 1

Convert a character column in a dataframe into a numeric column in R

I'm trying to convert some financial data I scrapped, and it has turned into a big headache! I've tried most things out there like using as.numeric(as.character()) and it does not seem to work. What REALLY throws me off is how it can filter using Close >= 20 if it's a Character!? And I can plot it, but not do any mathematical operations! Not sure if this is an artifact of having it in a dataframe? Any help would be appreciated.

# Links to oil futures prices and downloads them

library(dplyr)

oilurl <- "http://quotes.ino.com/exchanges/contracts.html?r=NYMEX_CL"

download.file(oilurl, destfile = ".../Strip/OilStrip.html")

oilhtml <- read_html("..../Strip/OilStrip.html")

# Puts the Oil data into a df

wti_df <- as.data.frame(read_html("..../Strip/OilStrip.html") %>% html_table(fill = TRUE))

colnames(wti_df) <- c("A","Date","C","D","E","Close","G","H","I")

# Cleans up the data into just Dates and Close price, removes any less than $20

wti_df <- select(wti_df,Date,Close)

wti_df <- slice(wti_df, 3:1023)

wti_df <- filter(wti_df,Close >= 20)

#turn "Close" into numeric

transform(wti_df, Close = as.numeric)

I've tried pretty much everything to make the column into a numeric and this is the closest I get. Here is the summary

> summary(wti_df$Close)
      Length Class  Mode   
 [1,] 1      -none- numeric
 [2,] 1      -none- numeric

But when I try and do anything like add a number to Close column or plot the data....

> plot(wti_df$Close)
Error in xy.coords(x, y, xlabel, ylabel, log) : 
  'x' is a list, but does not have components 'x' and 'y'

> 5.0 + wti_df$Close
Error in 5 + wti_df$Close : non-numeric argument to binary operator

Upvotes: 0

Views: 830

Answers (1)

juliamm2011
juliamm2011

Reputation: 136

"Transform" has some issues when giving it multiple arguments simultaneously (such as asking it to first apply "as.character" then "as.numeric" to your column. Maybe try a simpler approach to see if transform is your problem, or if something else is going on with your data.

wti_df$Close <- as.numeric(as.character(wti_df$Close))

Upvotes: 1

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