[R-SIG-Mac] Rolling average length issue

[David Winsemius]

On Nov 6, 2010, at 3:00 PM, Gerald Jurasinski wrote:

> Hi Sandy,
>
> Why don't you usw runmean() of the caTools package??
> In the see also section of the help for runmean() there are various  
> other possibilities given.

Also rollmean or rollapply in package zoo. Eg:

library(zoo)
rollmean(as.zoo(1:25), 5)

>
> Good Luck
> Gerald
>
> ——————
> 3rd Law of Computing:
>    Anything that can go wr
> fortune: Segmentation violation -- Core dumped
>
>
> Am 06.11.2010 um 02:44 schrieb David Winsemius:
>
>>
>> On Nov 5, 2010, at 12:03 PM, Sandy Zelka wrote:
>>
>>>
>>> Please help....I'm trying to calculate a 5-point rolling average  
>>> and I keep getting a length issue.
>>> My script is
>>
>> Not a SIG-Mac issue.
>>
>>>
>>> ma5<-function (x){
>>> y<-numeric(length(x-2)
>>> for(i in 2(length(x)-1)){
>>
>> You seem to missing an operator between 2 and (, and I am guessing  
>> you meant to type "*" or ":") but it is not clear SINCE YOU HAVE  
>> NOT DESCRIBED THE PROBLEM WELL. (And you have not posted the exact  
>> error message either.)
>>
>> Also check FAQ for description of problems related to the hierarchy  
>> of arithmetic operators in R (I don't actually remember a FAQ  
>> nubmber for this one but it is "frequently asked":
>>> x <- 1:10
>>> 2:length(x) -1
>> [1] 1 2 3 4 5 6 7 8 9
>>
>>
>>> y[i]]<-(x[i-3]+x[i-2]+x[i-1]+x[i]+x[i+1]))/5
>>
>> So have you checked at the ends of your ranges to see if these  
>> indices are meaningful? What is length(x) and would it be  
>> meaningful to request x[2-1 -3]? What is x[-2]  (or perhaps  
>> x[1-3] ) , after all? Or x[length(x)
>>
>>
>>> }
>>> Y}
>>>
>>> I keep getting a replacement has length zero
>>> I’ve tried changing the (x-2) to -3 and -4 and still get the same  
>>> issue.
>>
>> More likely that the extremes would raise "out of range" problems  
>> than the "interior" indices.
>>
>>> I’m thinking that it should be -2 and that this issue is in the  
>>> third line – any ideas?
>>
>> Better problem description, better punctuation,  and posting to  
>> rhelp.
>>
>>
>> -- 
>> David.
>>>
>>>
>>> Sandy Zelka, CPA, CAE, MBA, LB
>>> Accounting Professor
>>> (518) 469-8040
>>>
>>>
>>> 		 	   		
>>> 	[[alternative HTML version deleted]]
>>>
>>> _______________________________________________
>>> R-SIG-Mac mailing list
>>> R-SIG-Mac at stat.math.ethz.ch
>>> https://stat.ethz.ch/mailman/listinfo/r-sig-mac
>>
>> David Winsemius, MD
>> West Hartford, CT
>>
>> _______________________________________________
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>

David Winsemius, MD
West Hartford, CT