R help - Oct 2010 - Truncating leading zeros in strings

I am new to R.  I thing this will be simple, but I don't yet know my way 
around.

I am generating character strings from the system clock that represent 
integers, and I want to convert them to integer values.  Strtoi works 
well, except when there are leading zeros on the string.  Could anyone 
suggest a way to remove those leading zeros?

Thanks

Paul






-- 
E. Paul Wileyto, Ph.D.
Assistant Professor of Biostatistics
Tobacco Use Research Center
School of Medicine, U. of Pennsylvania
3535 Market Street, Suite 4100
Philadelphia, PA  19104-3309

215-746-7147
Fax: 215-746-7140
epw at upenn.edu

On Oct 7, 2010, at 9:57 AM, E. Paul Wileyto wrote:
>
> I am new to R.  I thing this will be simple, but I don't yet know my  
> way around.
>
> I am generating character strings from the system clock that  
> represent integers, and I want to convert them to integer values.   
> Strtoi works well, except when there are leading zeros on the  
> string.  Could anyone suggest a way to remove those leading zeros?
as.integer doesn't work? (If you are dealing in different base than  
10, then you really should say so.)

 > as.integer("0000123")
[1] 123

Or pass through sub("^[0]+", "", vals)
 > sub("^[0]+", "", "0000123")
[1] "123"

An example is expected in such situations. Please do now read the  
Posting Guide.
-- 

David Winsemius, MD
West Hartford, CT

Hi,

Think I might be misunderstanding what you want, because ...
> t = "0000123"
> as.integer(t)
[1] 123


anyway
> t = "0000123"
> substr(t,regexpr("[^0]",t),nchar(t))
[1] "123"

seems to trim the leading 0's

Martyn

-----Original Message-----
From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
On Behalf Of E. Paul Wileyto
Sent: 07 October 2010 14:58
To: r-help at r-project.org
Subject: [R] Truncating leading zeros in strings


I am new to R.  I thing this will be simple, but I don't yet know my way

around.

I am generating character strings from the system clock that represent 
integers, and I want to convert them to integer values.  Strtoi works 
well, except when there are leading zeros on the string.  Could anyone 
suggest a way to remove those leading zeros?

Thanks

Paul






-- 
E. Paul Wileyto, Ph.D.
Assistant Professor of Biostatistics
Tobacco Use Research Center
School of Medicine, U. of Pennsylvania
3535 Market Street, Suite 4100
Philadelphia, PA  19104-3309

215-746-7147
Fax: 215-746-7140
epw at upenn.edu

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