Subset

myDF <- data.frame(a = c("<0.1", NA, 0.3, 5, "Nil"),
                   b = c("<0.1", 1, 0.3, 5, "Nil"),
                   stringsAsFactors = FALSE)

# you can subset the b-column in several ways

myDF[ , 2]
myDF[ , "b"]
myDF$b

# using the column, you make a logical vector
! is.na(as.numeric(myDF$b))


# This can be used to select the rows you want

myDF[! is.na(as.numeric(myDF$b)), ]



B.

On Sep 25, 2017, at 7:30 AM, Shane Carey <careyshan at gmail.com> wrote:

Hi,

Lets say this was a dataframe where I had two columns

a <- c("<0.1", NA, 0.3, 5, "Nil")
b <- c("<0.1", 1, 0.3, 5, "Nil")

And I just want to remove the rows from the dataframe where there were

NAs in the b column, what is the syntax for doing that?

Thanks in advance

On Fri, Sep 22, 2017 at 5:04 PM, Shane Carey <careyshan at gmail.com>

wrote:

Super,

Thanks

On Fri, Sep 22, 2017 at 4:57 PM, Boris Steipe <boris.steipe at utoronto.ca>

wrote:

a <- c("<0.1", NA, 0.3, 5, "Nil")
a

[1] "<0.1" NA     "0.3"  "5"    "Nil"

b <- as.numeric(a)

Warning message:
NAs introduced by coercion

b

[1]  NA  NA 0.3 5.0  NA

b[! is.na(b)]

[1] 0.3 5.0


B.

On Sep 22, 2017, at 11:48 AM, Shane Carey <careyshan at gmail.com> wrote:

Hi,

How do I extract just numbers from the following list:

a=c("<0.1",NA,0.3,5,Nil)

so I want to obtain: 0.3 and 5 from the above list

Thanks


--
Le gach dea ghui,
*Shane Carey*
*GIS and Data Solutions Consultant*

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Le gach dea ghui,
Shane Carey
GIS and Data Solutions Consultant



--
Le gach dea ghui,
Shane Carey
GIS and Data Solutions Consultant