Dear RUsers, I guess this is an easy question for someone a little familiar with programming...(which I am not)... I've got 2 colummns, one shows just dates(SST_date, Class 'Date' num), the other one shows the SeaSurfaceTemperature (SST, num) at that certain date. SST_date SST 2008-01-01 22.2 2008-01-02 21.8 2008-01-03 22.8 2008-01-04 22.9 2008-01-05 23.1 2008-01-06 23.2 ... ... now, I would like to add a column that shows the mean SST over the last (e.g.) 60 days (for that specific date). My biological question is, whether the birthweight of an animal at a specific birthdate changes due to the SST over the last 60 days before birth. (SST is an indicator for food abundance - if food is scarce, mothers can't feed much and hence, pups are born lighter!?) Up to now, I can only show, whether the SeaSurfaceTemperatures on the birthdate can have an influence on birthweight, which is not what I want to do... Can anybody tell me, how to start, where to look it up or help me even more? thanks in advance. Birte -- View this message in context: http://www.nabble.com/mean-over-previous-cells-tp22116807p22116807.html Sent from the R help mailing list archive at Nabble.com.
If, suppose, the name of your dataframe is "dataframe" , you could try
something like:
mean60days<-c()
for(i in 1:length(dataframe$SST))
+ {
+ mean60days[[i]]<-mean(dataframe$SST[i-10:i])
+ }
I'm not really sure it will work... my skills aren't that great...
Anyway, it worked on a sample I tried it on, but you have to be careful and
discard the first 60 values!!
Hope it works,
ciao
Laura
Dear RUsers,
I guess this is an easy question for someone a little familiar with
programming...(which I am not)...
I've got 2 colummns, one shows just dates(SST_date, Class 'Date'
num), the
other one shows the SeaSurfaceTemperature (SST, num) at that certain date.
SST_date SST
2008-01-01 22.2
2008-01-02 21.8
2008-01-03 22.8
2008-01-04 22.9
2008-01-05 23.1
2008-01-06 23.2
...
...
now, I would like to add a column that shows the mean SST over the last
(e.g.) 60 days (for that specific date).
My biological question is, whether the birthweight of an animal at a
specific birthdate changes due to the SST over the last 60 days before
birth. (SST is an indicator for food abundance - if food is scarce, mothers
can't feed much and hence, pups are born lighter!?)
Up to now, I can only show, whether the SeaSurfaceTemperatures on the
birthdate can have an influence on birthweight, which is not what I want to
do...
Can anybody tell me, how to start, where to look it up or help me even more?
thanks in advance.
Birte
--
View this message in context:
http://www.nabble.com/mean-over-previous-cells-tp22116807p22116807.html
Sent from the R help mailing list archive at Nabble.com.
______________________________________________
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.
Sorry, I meant:
If, suppose, the name of your dataframe is "dataframe" , you could try
something like:
mean60days<-c()
for(i in 1:length(dataframe$SST))
+ {
+ mean60days[[i]]<-mean(dataframe$SST[i-60:i])
+ }
I'm not really sure it will work... my skills aren't that great...
Anyway, it worked on a sample I tried it on, but you have to be careful and
discard the first 60 values!!
Hope it works,
ciao
Laura
Dear RUsers,
I guess this is an easy question for someone a little familiar with
programming...(which I am not)...
I've got 2 colummns, one shows just dates(SST_date, Class 'Date'
num), the
other one shows the SeaSurfaceTemperature (SST, num) at that certain date.
SST_date SST
2008-01-01 22.2
2008-01-02 21.8
2008-01-03 22.8
2008-01-04 22.9
2008-01-05 23.1
2008-01-06 23.2
...
...
now, I would like to add a column that shows the mean SST over the last
(e.g.) 60 days (for that specific date).
My biological question is, whether the birthweight of an animal at a
specific birthdate changes due to the SST over the last 60 days before
birth. (SST is an indicator for food abundance - if food is scarce, mothers
can't feed much and hence, pups are born lighter!?)
Up to now, I can only show, whether the SeaSurfaceTemperatures on the
birthdate can have an influence on birthweight, which is not what I want to
do...
Can anybody tell me, how to start, where to look it up or help me even more?
thanks in advance.
Birte
--
View this message in context:
http://www.nabble.com/mean-over-previous-cells-tp22116807p22116807.html
Sent from the R help mailing list archive at Nabble.com.
______________________________________________
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.
Using the zoo package:
Lines <- "SST_date SST
2008-01-01 22.2
2008-01-02 21.8
2008-01-03 22.8
2008-01-04 22.9
2008-01-05 23.1
2008-01-06 23.2"
library(zoo)
# z <- read.zoo("myfile.dat", header = TRUE)
z <- read.zoo(textConnection(Lines), header = TRUE)
merge(z, avg3 = rollmean(z, 3, align = "right"))
See the three zoo vignettes (pdf documents) for more info on zoo.
On Fri, Feb 20, 2009 at 3:38 AM, clion <birte_2 at hotmail.com>
wrote:>
> Dear RUsers,
> I guess this is an easy question for someone a little familiar with
> programming...(which I am not)...
>
> I've got 2 colummns, one shows just dates(SST_date, Class
'Date' num), the
> other one shows the SeaSurfaceTemperature (SST, num) at that certain date.
>
> SST_date SST
> 2008-01-01 22.2
> 2008-01-02 21.8
> 2008-01-03 22.8
> 2008-01-04 22.9
> 2008-01-05 23.1
> 2008-01-06 23.2
> ...
> ...
>
> now, I would like to add a column that shows the mean SST over the last
> (e.g.) 60 days (for that specific date).
>
> My biological question is, whether the birthweight of an animal at a
> specific birthdate changes due to the SST over the last 60 days before
> birth. (SST is an indicator for food abundance - if food is scarce, mothers
> can't feed much and hence, pups are born lighter!?)
> Up to now, I can only show, whether the SeaSurfaceTemperatures on the
> birthdate can have an influence on birthweight, which is not what I want to
> do...
>
> Can anybody tell me, how to start, where to look it up or help me even
more?
> thanks in advance.
> Birte
>
> --
> View this message in context:
http://www.nabble.com/mean-over-previous-cells-tp22116807p22116807.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> 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.
>