R help - Feb 2016 - Grep Help

Hi,

# 1) I have read in a CSV file

df = read.csv(file="GiftCards - v1.csv",stringsAsFactors=FALSE)
head(df)
str(df)

# 2) converted to a tbl_df
df2 = tbl_df(df)

# 3) fixed the names to remove leading "X" character
n = names(df2)
n2 = gsub(pattern="^\\w","\\1",n)
names(df2) = n2

# 4) somehow the col names are character strings, requiring me to use
quotes:
df2$`2006` instead of df2$2006 # ---> PROBLEM 1


# 5) I need to remove the leading $ sign followed by spaces to extract
values. The problem is # it could be a two or three digit number. I am able
to retrieve two digits correctly, but miss # out on the leading third digit.
df2$`2006`=
gsub("^(.+)([0-9]{2,3}\\.[0-9]{2})","\\2",df2$`2006`) #
-->
Problem 2

# 6) dump for the data frame

df2 <-
structure(list(`2006` = structure(c(3L, 2L, 1L), .Label = c("$
24.81",
"$     39.16", "$   146.20"), class = "factor"),
`2007` = structure(c(3L,
2L, 1L), .Label = c("$       26.25", "$     41.95", "$ 
156.24"
), class = "factor"), `2008` = structure(c(3L, 2L, 1L), .Label =
c("$
24.92",
"$     40.54", "$   147.33"), class = "factor"),
`2009` = structure(c(3L,
2L, 1L), .Label = c("$       23.63", "$     39.80", "$ 
139.91"
), class = "factor"), `2010` = structure(c(3L, 2L, 1L), .Label =
c("$
24.78",
"$     41.48", "$   145.61"), class = "factor"),
`2011` = structure(c(3L,
2L, 1L), .Label = c("$       27.80", "$     43.23", "$ 
155.43"
), class = "factor"), `2012` = structure(c(3L, 2L, 1L), .Label =
c("$
28.79",
"$     43.75", "$   156.86"), class = "factor"),
`2013` = structure(c(3L,
2L, 1L), .Label = c("$       29.80", "$     45.16", "$ 
163.16"
), class = "factor")), .Names = c("2006", "2007",
"2008", "2009",
"2010", "2011", "2012", "2013"), class =
c("tbl_df", "tbl", "data.frame"
), row.names = c(NA, -3L))



Thanks for the help


Br /

	[[alternative HTML version deleted]]

I see numerous backticks in your code, not quotes. "`" and
"'" are not the same. Backticks are not string delimiters.
As for valid names: look at the help page for make.names().


HTH,
Boris



On Feb 22, 2016, at 1:32 PM, Burhan ul haq <ulhaqz at gmail.com> wrote:
> Hi,
> 
> # 1) I have read in a CSV file
> 
> df = read.csv(file="GiftCards - v1.csv",stringsAsFactors=FALSE)
> head(df)
> str(df)
> 
> # 2) converted to a tbl_df
> df2 = tbl_df(df)
> 
> # 3) fixed the names to remove leading "X" character
> n = names(df2)
> n2 = gsub(pattern="^\\w","\\1",n)
> names(df2) = n2
> 
> # 4) somehow the col names are character strings, requiring me to use
> quotes:
> df2$`2006` instead of df2$2006 # ---> PROBLEM 1
> 
> 
> # 5) I need to remove the leading $ sign followed by spaces to extract
> values. The problem is # it could be a two or three digit number. I am able
> to retrieve two digits correctly, but miss # out on the leading third
digit.
> df2$`2006`=
gsub("^(.+)([0-9]{2,3}\\.[0-9]{2})","\\2",df2$`2006`) #
-->
> Problem 2
> 
> # 6) dump for the data frame
> 
> df2 <-
> structure(list(`2006` = structure(c(3L, 2L, 1L), .Label = c("$
> 24.81",
> "$     39.16", "$   146.20"), class =
"factor"), `2007` = structure(c(3L,
> 2L, 1L), .Label = c("$       26.25", "$     41.95",
"$   156.24"
> ), class = "factor"), `2008` = structure(c(3L, 2L, 1L), .Label =
c("$
> 24.92",
> "$     40.54", "$   147.33"), class =
"factor"), `2009` = structure(c(3L,
> 2L, 1L), .Label = c("$       23.63", "$     39.80",
"$   139.91"
> ), class = "factor"), `2010` = structure(c(3L, 2L, 1L), .Label =
c("$
> 24.78",
> "$     41.48", "$   145.61"), class =
"factor"), `2011` = structure(c(3L,
> 2L, 1L), .Label = c("$       27.80", "$     43.23",
"$   155.43"
> ), class = "factor"), `2012` = structure(c(3L, 2L, 1L), .Label =
c("$
> 28.79",
> "$     43.75", "$   156.86"), class =
"factor"), `2013` = structure(c(3L,
> 2L, 1L), .Label = c("$       29.80", "$     45.16",
"$   163.16"
> ), class = "factor")), .Names = c("2006",
"2007", "2008", "2009",
> "2010", "2011", "2012", "2013"),
class = c("tbl_df", "tbl", "data.frame"
> ), row.names = c(NA, -3L))
> 
> 
> 
> Thanks for the help
> 
> 
> Br /
> 
> 	[[alternative HTML version deleted]]
> 
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