# [R] rounding up (always)

Dimitri Liakhovitski dimitri.liakhovitski at gmail.com
Thu Oct 21 02:38:23 CEST 2010

Thank you for your help, everyone.
Actually, I am building a lot of graphs (in a loop) but the values on
the y axes from graph to graph could range from [-5; 5] to [-10,000;
10,000].
So, I am trying to create ylim ranging from ymin to ymax such that
they look appropriate for the range.
For example, if we are taking the actual range from -4.28 to 6.45, I'd
like the range to be -5 to 7.
But if the range is from -1225 to 2248, then I'd like it to be from
-1500 to 2500 or from -2000 to 3000.
Hence, my original question.
Dimitri

On Wed, Oct 20, 2010 at 5:55 PM, Ted Harding <ted.harding at wlandres.net> wrote:
> On 20-Oct-10 21:27:46, Duncan Murdoch wrote:
>> On 20/10/2010 5:16 PM, Dimitri Liakhovitski wrote:
>>> Hello!
>>>
>>> I am trying to round the number always up - i.e., whatever the
>>> positive number is, I would like it to round it to the closest 10 that
>>> is higher than this number, the closest 100 that is higher than this
>>> number, etc.
>>>
>>> For example:
>>> x<-3241.388
>>>
>>> signif(x,1) rounds to the closest thousand, i.e., to 3,000, but I'd
>>> like to get 4,000 instead.
>>> signif(x,2) rounds to the closest hundred, i.e., to 3,200, but I'd
>>> like to get 3,300 instead.
>>> signif(x,3) rounds to the closest ten, i.e., to 3,240, but I'd like to
>>>
>>> Of course, I could do:
>>> floor(signif(x,1)+1000)
>>> floor(signif(x,2)+100)
>>> floor(signif(x,3)+10)
>>>
>>> But it's very manual - because in the problem I am facing the numbers
>>> sometimes have to be rounded to a 1000, sometimes to a 100, etc.
>>
>> Write a function.  You have very particular needs, so it's unlikely
>> there's already one out there that matches them.
>> Duncan Murdoch
>
> As Duncan and Clint suggest, writing a function is straightforward:
> for the problem as you have stated it, on the lines of
>
>  function(x,k){floor(signif(x,k-as.integer(log(x,10)-1))) + 10^k}
>
> However, what do you *really* want to happen to 3000?
>
> Ted.
>
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> E-Mail: (Ted Harding) <ted.harding at wlandres.net>
> Fax-to-email: +44 (0)870 094 0861
> Date: 20-Oct-10                                       Time: 22:55:47
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--
Dimitri Liakhovitski
Ninah Consulting
www.ninah.com