head {SparkR} | R Documentation |
Return the first NUM rows of a SparkDataFrame as a data.frame. If NUM is NULL, then head() returns the first 6 rows in keeping with the current data.frame convention in R.
## S4 method for signature 'SparkDataFrame' head(x, num = 6L)
x |
A SparkDataFrame |
num |
The number of rows to return. Default is 6. |
A data.frame
Other SparkDataFrame functions: $
,
$<-
, select
,
select
,
select,SparkDataFrame,Column-method
,
select,SparkDataFrame,list-method
,
selectExpr
;
SparkDataFrame-class
,
dataFrame
; [
,
[[
, subset
;
agg
, agg
,
count,GroupedData-method
,
summarize
, summarize
;
arrange
, arrange
,
arrange
, orderBy
,
orderBy
, orderBy
,
orderBy
; as.data.frame
,
as.data.frame,SparkDataFrame-method
;
attach
,
attach,SparkDataFrame-method
;
cache
; collect
;
colnames
, colnames
,
colnames<-
, colnames<-
,
columns
, names
,
names<-
; coltypes
,
coltypes
, coltypes<-
,
coltypes<-
; columns
,
dtypes
, printSchema
,
schema
, schema
;
count
, nrow
;
dapply
, dapply
,
dapplyCollect
, dapplyCollect
;
describe
, describe
,
describe
, summary
,
summary
,
summary,AFTSurvivalRegressionModel-method
,
summary,GeneralizedLinearRegressionModel-method
,
summary,KMeansModel-method
,
summary,NaiveBayesModel-method
;
dim
; distinct
,
unique
; dropDuplicates
,
dropDuplicates
; dropna
,
dropna
, fillna
,
fillna
, na.omit
,
na.omit
; drop
,
drop
; dtypes
;
except
, except
;
explain
, explain
;
filter
, filter
,
where
, where
;
first
, first
;
groupBy
, groupBy
,
group_by
, group_by
;
histogram
; insertInto
,
insertInto
; intersect
,
intersect
; isLocal
,
isLocal
; join
;
limit
, limit
;
merge
, merge
;
mutate
, mutate
,
transform
, transform
;
ncol
; persist
;
printSchema
; rbind
,
rbind
, unionAll
,
unionAll
; registerTempTable
,
registerTempTable
; rename
,
rename
, withColumnRenamed
,
withColumnRenamed
;
repartition
; sample
,
sample
, sample_frac
,
sample_frac
;
saveAsParquetFile
,
saveAsParquetFile
,
write.parquet
, write.parquet
;
saveAsTable
, saveAsTable
;
saveDF
, saveDF
,
write.df
, write.df
,
write.df
; selectExpr
;
showDF
, showDF
;
show
, show
,
show,GroupedData-method
,
show,WindowSpec-method
; str
;
take
; unpersist
;
withColumn
, withColumn
;
write.jdbc
, write.jdbc
;
write.json
, write.json
;
write.text
, write.text
## Not run: sc <- sparkR.init() sqlContext <- sparkRSQL.init(sc) path <- "path/to/file.json" df <- read.json(sqlContext, path) head(df) ## End(Not run)