[R] Challenge extracting months

Kwesi Quagraine starskykwesi at gmail.com
Wed Feb 1 19:26:27 CET 2017


Hello Jim, Hello everyone, does anyone know why this is happening? Any
suggestions what might be causing it? I will be grateful for any help.

Kwesi

On Wed, Feb 1, 2017 at 1:12 AM, Jim Lemon <drjimlemon at gmail.com> wrote:

> Hi Kwesi,
> I worked through your code below, and I think that when you have the
> two variables "mon.t1" and "seas.t1" you can select a "rolling
> quarter" like this:
>
> # the file name in your example is different from the one you sent
> era<-read.table(file="SAfr_700hpa_7x5II.txt",header=FALSE,sep=" ",
>  skip=1,dec = ".")
> era.nodes<-paste(era[,1],era[,2],sep=".")
> era.nodes<-as.numeric(era.nodes)
> era.nodes.days<-zooreg(era.nodes,start=as.Date("1980-01-01"),
>  end=as.Date("2016-12-31"))
> era.nodes.days.t1<-window(era.nodes.days,start=as.Date("1980-01-01"),
>  end=as.Date("2016-12-31"))
> mon.t1<-as.numeric(format(index(era.nodes.days.t1),"%m"))
> addyear<-0
> # this loop transforms mon.t1 into an increasing sequence of months
> for(i in 2:length(mon.t1)) {
>  if(seas.t1[i] > seas.t1[i-1]) addyear<-addyear+12
>  mon.t1[i]<-mon.t1[i] + addyear
> }
> for(i in 1:(max(mon.t1)-2)) {
>  # this gives a logical index for the rolling quarter
>  rq<-mon.t1 %in% i:(i+2)
> }
>
> Each successive "rq" produced by the last loop can be used to extract
> whatever values you want from "era" or "era.nodes".
>
> Jim
>
>
> On Tue, Jan 31, 2017 at 9:04 PM, Kwesi Quagraine <starskykwesi at gmail.com>
> wrote:
> > Hello Jim, thanks for the code. But I come to you once again, I am not
> > looking to do a rolling mean, but to select JFM,FMA,MAM etc from the data
> > attached. Below is my sample code which actually selects these months. I
> > will rather be glad if I can have a function that does the selection for
> all
> > these 3 months selected for each year as shown in my last two lines of
> code;
> > Taking into accounts years with 29 days in February etc.
> >
> > rm(list = ls())
> > library(zoo)
> > library(PCICt)
> > library(lattice)
> > library(RColorBrewer)
> >
> > setwd('/home/kwesi/Documents/700hpa/soms/')
> > # Reading the data
> >
> > era       <- read.table(file="SAfr_700hpa_5x4II.txt",header = FALSE,
> sep =
> > "",skip=1,dec = ".")
> > era.nodes      <- paste(era[,1],era[,2],sep=".")
> >
> > era.nodes      <-as.numeric(era.nodes)
> > era.nodes.days<-zooreg(era.nodes,start=as.Date("1980-01-
> 01"),end=as.Date("2016-12-31"))
> >
> > era.nodes.days.t1<-window(era.nodes.days,start=as.Date("
> 1980-01-01"),end=as.Date("2016-12-31"))
> >
> > mon.t1<-as.numeric(format(index(era.nodes.days.t1),"%m"))
> > seas.t1 <-as.numeric(format(index(era.nodes.days.t1),"%Y"))
> > era.nodes.days.t1<-cbind(era.nodes.days.t1,mon.t1,seas.t1)
> > era.nodes.days.t1
> > jfm80<-era.nodes.days.t1[1:91,1:3[era.nodes.days.t1[1:91,2]=
> =1|era.nodes.days.t1[1:91,2]==2|era.nodes.days.t1[1:91,2]==3]
> > fma80<-era.nodes.days.t1[32:(91+30),1:3
> > [era.nodes.days.t1[1:91,2]==2|era.nodes.days.t1[1:91,2]==3|
> era.nodes.days.t1[1:91,2]==4]
> >
> > On Tue, Jan 31, 2017 at 5:23 AM, Jim Lemon <drjimlemon at gmail.com> wrote:
> >>
> >> Hi Kwesi,
> >> A mistake in the last email. Don't try to replace the column in
> >> era.sta as the result will be a different length. Try this:
> >>
> >> newera.sta2<-collapse.values(era.sta[,2],3)
> >>
> >> Jim
> >>
> >> On Tue, Jan 31, 2017 at 10:32 AM, Jim Lemon <drjimlemon at gmail.com>
> wrote:
> >> > Hi Kwesi,
> >> > The function collapse_values will only work on a vector of numbers
> >> > with FUN="mean". era.sta looks like a data frame with at least two
> >> > elements. As the second of these elements seems to be numeric, perhaps
> >> > this will work:
> >> >
> >> > era.sta[,2]<-collapse.values(era.sta[,2],3)
> >> >
> >> > Don't try to apply the names to era.sta, that was just something to
> >> > make the example easier to understand. If you want to collapse more
> >> > than one column of era.sta do each one at a time and assign them to a
> >> > new data frame. In particular, if era[,1] is a vector of month names,
> >> > you will have to create a new vector of quarter (three month) names.
> >> > If there are very many of these, the collapse_values function can be
> >> > modified to do it automatically.
> >> >
> >> > Jim
> >> >
> >> >
> >> >
> >> > On Tue, Jan 31, 2017 at 9:50 AM, Kwesi Quagraine
> >> > <starskykwesi at gmail.com> wrote:
> >> >> Hello Jim,this is my script now; I am having this error when I called
> >> >> the
> >> >> function;" In mean.default(list(era...1. = 1:444, Node_freq =
> >> >> c(-0.389855332400718,  :  argument is not numeric or logical:
> returning
> >> >> NA"
> >> >> Any help will be much appreciated.
> >> >>
> >> >> Kwesi
> >> >>
> >> >> rm(list = ls())
> >> >> setwd('/home/kwesi/Documents/700hpa/soms/')
> >> >> # Reading the data
> >> >>
> >> >> era       <- read.csv(file="som_freq.csv",header = TRUE, sep =
> ",",dec
> >> >> =
> >> >> ".")
> >> >> era.scaled <- scale(era[,2:3], center = TRUE, scale = TRUE)
> >> >> era.sta<-data.frame(era[,1],era.scaled)
> >> >> era.sta
> >> >>
> >> >> collapse_values<-function(x,span,FUN="mean",na.rm=FALSE) {
> >> >>   jump<-span-1
> >> >>   newx<-rep(NA,length(x)-jump)
> >> >>   for(i in 1:length(newx))
> >> >>     newx[i]<-do.call(FUN,list(x[i:(i+jump)],na.rm=na.rm))
> >> >>   return(newx)
> >> >> }
> >> >>
> >> >> #test<-1:12
> >> >> names(era.sta)<-month.abb
> >> >> collapse_values(era.sta,3)
> >> >> era.sta
> >> >>
> >> >>
> >> >> On Mon, Jan 30, 2017 at 11:53 PM, Jim Lemon <drjimlemon at gmail.com>
> >> >> wrote:
> >> >>>
> >> >>> Hi Kwesi,
> >> >>> Even without the data, it seems clear that you want something like a
> >> >>> rolling mean. Here is a simple function that will apply a function
> >> >>> like "mean" to successive bits of a vector of numbers:
> >> >>>
> >> >>> collapse_values<-function(x,span,FUN="mean",na.rm=FALSE) {
> >> >>>  jump<-span-1
> >> >>>  newx<-rep(NA,length(x)-jump)
> >> >>>  for(i in 1:length(newx))
> >> >>>   newx[i]<-do.call(FUN,list(x[i:(i+jump)],na.rm=na.rm))
> >> >>>  return(newx)
> >> >>> }
> >> >>>
> >> >>> test<-1:12
> >> >>> names(test)<-month.abb
> >> >>> test
> >> >>> collapse_values(test,3)
> >> >>>  [1]  2  3  4  5  6  7  8  9 10 11
> >> >>>
> >> >>> Jim
> >> >>>
> >> >>>
> >> >>>
> >> >>> On Mon, Jan 30, 2017 at 11:53 PM, Kwesi Quagraine
> >> >>> <starskykwesi at gmail.com> wrote:
> >> >>> > Hello, I have a data with two variables nodes and index, I want to
> >> >>> > extract
> >> >>> > 3 months seasons, with a shift of 1 month, that is, DJF, JFM, FMA
> >> >>> > etc to
> >> >>> > OND. Was wondering how to go about it. Kindly find attached the
> data
> >> >>> > as
> >> >>> > csv.
> >> >>> > Any help will be appreciated.
> >> >>> >
> >> >>> > Regards,
> >> >>> > Kwesi
> >> >>> >
> >> >>> > --
> >> >>> > Try not to become a man of success but rather a man of
> value-Albert
> >> >>> > Einstein
> >> >>> >
> >> >>> > University of Cape Coast|College of Agriculture and Natural
> >> >>> > Sciences|Department
> >> >>> > of Physics|
> >> >>> > Team Leader|Recycle Up! Ghana|Technology Without Borders|
> >> >>> > Other emails: kwesi.quagraine at ucc.edu.gh|kwesi.quagraine at teog.de|
> >> >>> > Mobile: +233266173582
> >> >>> > Skype: quagraine_cwasi
> >> >>> > Twitter: @Pkdilly
> >> >>> > ______________________________________________
> >> >>> > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >> >>> > 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.
> >> >>
> >> >>
> >> >>
> >> >>
> >> >> --
> >> >> Try not to become a man of success but rather a man of value-Albert
> >> >> Einstein
> >> >>
> >> >> University of Cape Coast|College of Agriculture and Natural
> >> >> Sciences|Department of Physics|
> >> >> Team Leader|Recycle Up! Ghana|Technology Without Borders|
> >> >> Other emails: kwesi.quagraine at ucc.edu.gh|kwesi.quagraine at teog.de|
> >> >> Mobile: +233266173582
> >> >> Skype: quagraine_cwasi
> >> >> Twitter: @Pkdilly
> >> >>
> >
> >
> >
> >
> > --
> > Try not to become a man of success but rather a man of value-Albert
> Einstein
> >
> > University of Cape Coast|College of Agriculture and Natural
> > Sciences|Department of Physics|
> > Team Leader|Recycle Up! Ghana|Technology Without Borders|
> > Other emails: kwesi.quagraine at ucc.edu.gh|kwesi.quagraine at teog.de|
> > Mobile: +233266173582
> > Skype: quagraine_cwasi
> > Twitter: @Pkdilly
> >
>



-- 
Try not to become a man of success but rather a man of value-Albert Einstein

University of Cape Coast|College of Agriculture and Natural Sciences|Department
of Physics|
Team Leader|Recycle Up! Ghana|Technology Without Borders|
Other emails: kwesi.quagraine at ucc.edu.gh|kwesi.quagraine at teog.de|
Mobile: +233266173582
Skype: quagraine_cwasi
Twitter: @Pkdilly
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