[R] Apply a shift which is a function of the array.

[Robin Hankin]

Hello Jim

you can use ashift() from the same library which does (I think) what you 
want.


HTH,   Robin



On 07/02/2010 12:05 PM, Jim Hargreaves wrote:
> Dear List,
>
> I have a 2,000x10,000 array of time domain data which when plotted 
> draws a distinct pulse. The matrix is 10,000 pulses of length 2000. I 
> would like the pulse to be shifted so that the peak (which.max of the 
> pulse data) is consistently at point 400.
>
> I don't want to use loops as it'll take a long time. The problem with 
> using apply is the pulse peak varies for each pulse, so I want to use 
> something like:
>
> apply(really_mean_pulse, 2, shift, which.max(really_mean_pulse))
>
> (Using the shift function from the "magic" library)
>
> This doesn't work, so I need to modify this so that the argument to 
> shift is dependent on the column the shift is being applied to.
>
> Any suggestions would be greatly appreciated!
>
> Kind Regards,
> Jim Hargreaves
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.


-- 
Robin K. S. Hankin
Uncertainty Analyst
University of Cambridge
19 Silver Street
Cambridge CB3 9EP
01223-764877