[R] Count number in r

[John Kane]

If nothing suggested in this thread help I'd suggest asking in R-sig-Geo where they will be more familiar with the issues.

Please do not post in HTML. It can serious mangle code to the point it is indecipherable.  

John Kane
Kingston ON Canada

-----Original Message-----
From: johnwasige at gmail.com
Sent: Tue, 19 May 2015 18:26:35 +0200
To: jrkrideau at inbox.com
Subject: Re: [R] Count number in r

Dear all,

I am kindly requesting for help on how I can count pixels with value less and equal to -0.08 for a raster stack.

Thanks for your help

John

On Tue, May 19, 2015 at 5:57 PM, John Kane <jrkrideau at inbox.com> wrote:

	And another approach just for the heck of it.

 library(plyr)

 # where dat1 is your data
 dd1  <-  subset(dat1, Rain >= .01)

 dd1$Year  <-  as.factor(dd1$Year)
 dd1$Month  <-  as.factor(dd1$Month)

 count (dd1, .(Year, Month))

 John Kane

 Kingston ON Canada

 > -----Original Message-----
 > From: hafizuddinarshad21 at gmail.com
 > Sent: Tue, 19 May 2015 03:10:32 -0700
 > To: r-help at r-project.org
 > Subject: [R] Count number in r
 >
 > Dear R users,
 >
 > Could someone help me on this? I have this kind of data set:
 >
 > structure(list(Year = c(1971L, 1971L, 1971L, 1971L, 1971L, 1971L,
 > 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L,
 > 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L,
 > 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L,
 > 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L, 1971L,
 > 1971L, 1971L), Month = c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
 > 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
 > 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L,
 > 2L, 2L, 2L), Rain = c(58.9, 74.6, 17.7, 7.8, 1.2, 1, 5.3, 0.7,
 > 1.2, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 > 0, 10.4, 17.5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)), .Names =
 > c("Year",
 > "Month", "Rain"), class = "data.frame", row.names = c(NA, -44L
 > ))
 >
 > I want to count data in "Rain" that is greater and equal to 0.1 mm
 > according to their "Month" and "Year". I have used this code, but it
 > seems
 > so wrong.
 >
 > raindat <- read.csv('my data set',header=TRUE)
 > yearcorr<-min(raindat$Year)-1
 > years<-unique(raindat$Year)
 > rainmonth<-as.data.frame(matrix(0,nrow=2,ncol=12))
 > for(year in years) {
 >   for(month in 1:12) {
 >     if(any(raindat$Year==year&raindat$Month==month))
 >       rainmonth[year-yearcorr,month]<-
 >       length((which(raindat$Rain >=
 > 0.1))[raindat$Year==year&raindat$Month==month])
 >   }
 > }
 > rownames(rainmonth)<-years
 > names(rainmonth)<-month.abb
 > rainmonth
 >
 > Thank you so much.
 >
 >
 > Arshad
 >
 >       [[alternative HTML version deleted]]
 >
 > ______________________________________________
 > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
 > https://stat.ethz.ch/mailman/listinfo/r-help [https://stat.ethz.ch/mailman/listinfo/r-help]
 > PLEASE do read the posting guide
 > http://www.R-project.org/posting-guide.html [http://www.R-project.org/posting-guide.html]
 > and provide commented, minimal, self-contained, reproducible code.

____________________________________________________________
 Can't remember your password? Do you need a strong and secure password?
 Use Password manager! It stores your passwords & protects your account.

 ______________________________________________
 R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
 https://stat.ethz.ch/mailman/listinfo/r-help [https://stat.ethz.ch/mailman/listinfo/r-help]
 PLEASE do read the posting guide http://www.R-project.org/posting-guide.html [http://www.R-project.org/posting-guide.html]
 and provide commented, minimal, self-contained, reproducible code.

-- 

John Wasige
"Birds born in a Cage think Flying is an illness."

____________________________________________________________
Can't remember your password? Do you need a strong and secure password?
Use Password manager! It stores your passwords & protects your account.