CODEWITHSUNDEEP
rplot
slingblade8129
slingblade8129

Reputation: 131

Why cannot I plot the graph in R?

I am having trouble plotting the graph. Everytime I try to plot it, instead of a line graph, I get a histogram like this -

enter image description here

I have attached the link to the csv file - https://docs.google.com/spreadsheets/d/1qaTqw9sSoOpeKIa5GnHr2cJ2_DKBb1-89eTukTtrKOQ/edit?usp=sharing

First 4 lines of data

Date        Comid       Low     High    Average Close   Trdno   Volume  Turnover    Company
01-01-2005  14,259.00   138.60  139.10  138.84  138.80  14.00   1,500.00    208,230.00  BRITISH AMERICAN TOBACCO BANGLADESH COMPANY LIMITED
02-01-2005  14,259.00   139.00  140.00  139.43  139.40  24.00   2,750.00    383,665.00  BRITISH AMERICAN TOBACCO BANGLADESH COMPANY LIMITED
03-01-2005  14,259.00   138.50  139.00  138.70  138.60  26.00   3,600.00    499,300.00  BRITISH AMERICAN TOBACCO BANGLADESH COMPANY LIMITED
04-01-2005  14,259.00   135.20  138.50  136.76  136.70  23.00   2,300.00    314,865.00  BRITISH AMERICAN TOBACCO BANGLADESH COMPANY LIMITED

I am trying to plot the 6th column (the one titled "Close" and I typed the following commands.

batbc <- read.csv("batbc.csv")
plot(batbc[, 6], type="l")

Upvotes: 2

Views: 166

Answers (2)

Frash
Frash

Reputation: 728

You need to read the csv with automatic factor conversion turned off.

Then you need to get rid of the thousands comma separator in that column (or for any relevant column).

Then coerce the character column to numeric. Directly coercing to numeric without thousands comma separator being handled will generate NA for rows having comma in.

Next you can plot normally. 

batbc <- read.csv('BATB.csv', as.is = T)
batbc$Close <- gsub(',','',batbc$Close)
batbc$Close <- as.numeric(batbc$Close)
plot(batbc[, 6], type="l")

HTH.

Upvotes: 0

Nick Kennedy
Nick Kennedy

Reputation: 12640

The problem is the commas as thousand separators. There are a few ways of solving this, but the neatest I've seen is from another SO answer.

For your data in particular, you need to do this:

setClass("num.with.commas")
setAs("character", "num.with.commas", 
      function(from) as.numeric(gsub(",", "", from)))
batbc <- read.csv("batbc.csv",
  colClasses = c("character", rep("num.with.commas", 7), "character"))

It should then work fine.

Note with the commas in place, the numbers are treated as character, and then converted to factors per the default behaviour of read.csv. When you try to plot a factor, you get a histogram. In that context, the type = "l" is ignored with a warning.

Upvotes: 1

Related Questions