R: how to convert factor vector into numeric (advices from other questions did not work)

Question

I am trying to convert a factor vector into numeric value without any changes in the value.

I looked up and found out some functions like

         bonds1 <- as.numeric(as.character(bonds$price)) 
         Warning message:
         NAs introduced by coercion 

         bonds1 <- as.numeric(levels(bonds$price)[bonds$price])
         Warning message:
         NAs introduced by coercion

but as it is shown above, warning signs keep coming up. Any ideas on why this is not working?

[figured it out]

It was the commas in bonds$price

         bonds$price <- as.numeric(gsub(",","",bonds$price))

@HubertL the column is a price of a bond. It looks something like this `10,045.26, 10,030.25....` I don't know why these prices cannot be converted to numeric.. — hk824, Mar 16 '16 at 01:28

score 2 · Answer 1 · answered Mar 16 '16 at 01:26

2

You can remove the comma with gsub():

as.numeric(gsub(",","",as.character(factor(c("1,000.23","2.2", "one")))))
[1] 1000.23    2.20      NA
Warning message:
NAs introduced by coercion

answered Mar 16 '16 at 01:26

HubertL

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score -1 · Accepted Answer · edited May 23 '17 at 12:24

Like @HurbtL has mentioned it seems values are not convertible.

Check these SO answers on how to avoid this warning

Parse numerics with commas:

how to avoid "Warning message: NAs introduced by coercion" in as.numeric()

N1 <- c("1000", "1,000", "10000", "10,000")
as.numeric(N1)
##
[1]  1000    NA 10000    NA
Warning message:
NAs introduced by coercion
##
> N2 <- gsub(",","",N1)
> as.numeric(N2)
[1]  1000  1000 10000 10000

Supress warning

How to avoid warning when introducing NAs by coercion

R: how to convert factor vector into numeric (advices from other questions did not work)

2 Answers2