| first {SparkR} | R Documentation |
Return the first row of a SparkDataFrame
Aggregate function: returns the first value in a group.
## S4 method for signature 'SparkDataFrame' first(x) ## S4 method for signature 'characterOrColumn' first(x, na.rm = FALSE)
x |
A SparkDataFrame |
The function by default returns the first values it sees. It will return the first non-missing value it sees when na.rm is set to true. If all values are missing, then NA is returned.
Other agg_funcs: agg,
approxCountDistinct, avg,
countDistinct, kurtosis,
last, max,
mean, min, n,
sd, skewness,
stddev_pop, stddev_samp,
sumDistinct, sum,
var_pop, var_samp,
var
Other SparkDataFrame functions: SparkDataFrame-class,
[[, agg,
arrange, as.data.frame,
attach, cache,
collect, colnames,
coltypes, columns,
count, dapply,
describe, dim,
distinct, dropDuplicates,
dropna, drop,
dtypes, except,
explain, filter,
group_by, head,
histogram, insertInto,
intersect, isLocal,
join, limit,
merge, mutate,
ncol, persist,
printSchema,
registerTempTable, rename,
repartition, sample,
saveAsTable, selectExpr,
select, showDF,
show, str,
take, unionAll,
unpersist, withColumn,
write.df, write.jdbc,
write.json, write.parquet,
write.text
## Not run:
##D sc <- sparkR.init()
##D sqlContext <- sparkRSQL.init(sc)
##D path <- "path/to/file.json"
##D df <- read.json(sqlContext, path)
##D first(df)
## End(Not run)
## Not run:
##D first(df$c)
##D first(df$c, TRUE)
## End(Not run)