[R] convert one digit numbers to two digits one

[Barry Rowlingson]

All these suggestions of using 'sprintf' might be right but you might
be doing it wrong...

If you are working with times, then use the date/time classes and the
handy functions for working on them. Which means the lubridate
package, most likely.

Are these times part of a calendar time, or are they just clock times
without reference to any day, or are they durations in hours and
minutes?



On Wed, Nov 6, 2013 at 4:34 PM, Marc Schwartz <marc_schwartz at me.com> wrote:
> On Nov 6, 2013, at 10:25 AM, Alaios <alaios at yahoo.com> wrote:
>
>> Hi all,
>> the following returns the hour and the minutes
>>
>> paste(DataSet$TimeStamps[selectedInterval$start,4], DataSet$TimeStamps[selectedInterval$start,5],sep=":")
>> [1] "12:3"
>>
>> the problem is that from these two I want to create a time stamp so 12:03. The problem is that the number 3 is not converted to 03. Is there an easy way when I have one digit integer to add a zero in the front? Two digits integers are working fine so far, 12:19, or 12:45 would appear correctly
>>
>> I would like to thank you in advance for your help
>>
>> Regards
>> Alex
>
>
> This is an example where using ?sprintf gives you more control:
>
>> sprintf("%02d:%02d", 12, 3)
> [1] "12:03"
>
>> sprintf("%02d:%02d", 9, 3)
> [1] "09:03"
>
>
> The syntax '%02d' tells sprintf to print the integer and pad with leading zeroes to two characters where needed.
>
> Regards,
>
> Marc Schwartz
>
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