[R] converting string vector to integer/numeric vector

[Joshua Wiley]

Hi Rajesh,

This will work, unfortunately it seems like lapply() drops the names
before it passes each element of the list which lead to my clumsy work
around using which().  I'm sure there are other ways.

dat <- list(INT = c("1","2","3"),
            NUM = c("2.34","4.56","6.78"),
            INT = c("4", "5", "6"),
            NUM = c("3.44"))

ints <- which(names(dat)=="INT")
nums <- which(names(dat)=="NUM")

dat[ints] <- lapply(dat[ints], as.integer)
dat[nums] <- lapply(dat[nums], as.numeric)

str(dat)

Cheers,

Josh

On Sun, Sep 5, 2010 at 6:33 AM, rajesh j <akshay.rajesh at gmail.com> wrote:
> The string vector actually comes as a part of a list, and the vector is
> named "int", and the numbers are strings. I then have to make it a vector
> that is still called "int" and has 4,5,6 etc. the types are either integer
> or numeric. The number of items in the vector is unknown.
>
> here's an example,
>
> a list has vectors
>
> INT
> "2"
> "3"
> "4"
>
> NUM
> "2.37"
> "4.56"
>
>
>
> On Sun, Sep 5, 2010 at 6:56 PM, David Winsemius <dwinsemius at comcast.net>wrote:
>
>>
>> On Sep 5, 2010, at 9:22 AM, rajesh j wrote:
>>
>> for e.g., I get the following as a string vector
>> "int" "4" "5" "6"
>> after reading the first element, I have to convert this to a integer vector
>>
>>
>>
>> But what is the right answer?  And what number of items are possble per
>> line?  And what are the other possible type identifiers? We need an example
>> that has enough complexity to allow testing.
>>
>> --
>> David.
>>
>>
>>
>> On Sun, Sep 5, 2010 at 6:44 PM, David Winsemius <dwinsemius at comcast.net>wrote:
>>
>>>
>>> On Sep 5, 2010, at 8:48 AM, rajesh j wrote:
>>>
>>>  Hi,
>>>>
>>>> Is it possible to convert a string vector to integer or numeric vector?
>>>> In
>>>> my situation I receive data in a string vector and have to convert it
>>>> based
>>>> on a given type.
>>>>
>>>
>>> Can you give an example? I don't understand either what sort of conversion
>>> you desire or what you mean by "convert it based on a given type."
>>>
>>> There are a couple of function you may want to consider but I am having
>>> difficulty convincing myself they answer the problem posed:
>>>
>>> ?charToRaw
>>> ?stroi
>>>
>>> > strtoi(charToRaw("123 this is a string"), base=16)   # convert to
>>> decimal ASCII
>>>  [1]  49  50  51  32 116 104 105 115  32 105 115  32  97  32 115 116 114
>>> 105 110 103
>>>
>>> --
>>>
>>> David Winsemius, MD
>>> West Hartford, CT
>>>
>>>
>>
>>
>> --
>> Rajesh.J
>>
>>
>>
>>  David Winsemius, MD
>> West Hartford, CT
>>
>>
>
>
> --
> Rajesh.J
>
>        [[alternative HTML version deleted]]
>
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>



-- 
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/