scala - Spark convert single column into array -


how can convert single column in spark 2.0.1 array?

+---+-----+ | id| dist|  +---+-----+ |1.0|2.0| |2.0|4.0| |3.0|6.0| |4.0|8.0| +---+-----+

should return array(1.0, 2.0, 3.0, 4.0)

a

import scala.collection.javaconverters._  df.select("id").collectaslist.asscala.toarray

fails with

java.lang.runtimeexception: unsupported array type: [lorg.apache.spark.sql.row; java.lang.runtimeexception: unsupported array type: [lorg.apache.spark.sql.row;

why use javaconverters if re-transform java list scala list ? need collect dataset , map array of rows array of doubles, :

df.select("id").collect.map(_.getdouble(0))

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