# R/chunkSummaryR.R In YuweiNi45/lng:

#### Documented in chunkSummaryR

```#' Chunk Summary
#'
#' Divide the whole dataset into four chunks and calculate the mean and standard deviation of each chunks.
#'
#'
#' @param data  A data frame
#'
#' @return A table is provided, which include the names of each column and the results.
#'
#' @examples
#' a<-rnorm(5,3)
#' b<-rnorm(5,7)
#' c<-cbind(a,b)
#' c<-data.frame(c)
#' chunkSummaryR(c)
#'
#'
#' @references Hadley Wickham (2015) R package.
#'
#'@export
chunkSummaryR<- function(data){
#Get the total numbers of rows
n<-nrow(data)

#Divide the rows into four parts
n1<-ceiling(n/4)
n2<-ceiling(n/2)
n3<-ceiling(3*n/4)
n4<-n

#Divide the whole dataset into four chunks based on rows
dat1<-data[1:n1,,]
dat2<-data[(n1+1):n2,,]
dat3<-data[(n2+1):n3,,]
dat4<-data[(n3+1):n4,,]

#Calculate the mean and standard deviation of each chunk
mean1<-round(apply(dat1,2,mean),2)
sd1<-round(apply(dat1,2,sd),2)
mean2<-round(apply(dat2,2,mean),2)
sd2<-round(apply(dat2,2,sd),2)
mean3<-round(apply(dat3,2,mean),2)
sd3<-round(apply(dat3,2,sd),2)
mean4<-round(apply(dat4,2,mean),2)
sd4<-round(apply(dat4,2,sd),2)

#Combine four chunks and the names of each column
names<-colnames(data)
out<-data.frame(Variables = names,
Chunk1 = data.frame(mean1,sd1),
Chunk2 = data.frame(mean2,sd2),
Chunk3 = data.frame(mean3,sd3),
Chunk4 = data.frame(mean4,sd4),
row.names = NULL)

#Export the final dataframe
out

}
```
YuweiNi45/lng documentation built on Oct. 21, 2018, 4:15 p.m.