question: @ Override public void mergeAndOutputTransformationMetadata ( Iterator < DistinctValue > values , String outputDir , int colID , FileSystem fs , TfUtils agents ) throws IOException { double min = Double . MAX_VALUE ; double max = - Double . MAX_VALUE ; int nbins = 0 ; DistinctValue val = new DistinctValue ( ) ; String w = null ; double d ; while ( values . hasNext ( ) ) { val . reset ( ) ; val = values . next ( ) ; w = val . getWord ( ) ; if ( w . startsWith ( MIN_PREFIX ) ) { d = UtilFunctions . parseToDouble ( w . substring ( MIN_PREFIX . length ( ) ) ) ; if ( d < min ) min = d ; } else if ( w . startsWith ( MAX_PREFIX ) ) { d = UtilFunctions . parseToDouble ( w . substring ( MAX_PREFIX . length ( ) ) ) ; if ( d > max ) max = d ; } else if ( w . startsWith ( NBINS_PREFIX ) ) { nbins = ( int ) UtilFunctions . parseToLong ( w . substring ( NBINS_PREFIX . length ( ) ) ) ; } else throw new RuntimeException ( "MVImputeAgent: Invalid prefix while merging map output: " + w ) ; } double binwidth = ( max - min ) / nbins ; writeTfMtd ( colID , Double . toString ( min ) , Double . toString ( max ) , Double . toString ( binwidth ) , Integer . toString ( nbins ) , outputDir , fs , agents ) ; }
target:  Method to merge map output transformation metadata.