Count number in r

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

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