collect

问题 I have a MultivaluedMap and a list of strings, and I would like to see which of those string are keys in the MultivaluedMap . For each of the strings that are keys in the MultivaluedMap , I want to construct a new Thing out of the value of that key, set that string as a new key in a new HashMap<String, Thing> , and set the new Thing I've created as the value for that new key in the HashMap . Right now, using a vanilla forEach , I have the following working solution: MultivaluedMap<String,

问题 I have been using SymPy to expand the terms of a complex partial differential equation and would like to use the collect function to gather terms. However, it seems to have a problem dealing with second (or higher order) derivatives where the variables of differentiation differ. In the code example below collect(expr6... works, but collect(expr7 ... does not, returning the error message "NotImplementedError: Improve MV Derivative support in collect" . The error is clearly related to the psi

来源： https://stackoverflow.com/questions/64204751/spark-collect-list-change-data-type-from-array-to-string

来源： https://stackoverflow.com/questions/64204751/spark-collect-list-change-data-type-from-array-to-string

来源： https://stackoverflow.com/questions/64204751/spark-collect-list-change-data-type-from-array-to-string

来源： https://stackoverflow.com/questions/64204751/spark-collect-list-change-data-type-from-array-to-string

来源： https://stackoverflow.com/questions/63837641/grouping-a-map-by-objects-property-to-a-new-map

来源： https://stackoverflow.com/questions/53292783/formatting-a-2d-int-array-into-a-string-using-streams

来源： https://stackoverflow.com/questions/53292783/formatting-a-2d-int-array-into-a-string-using-streams

问题 I am using Spark 1.5. I have a column of 30 ids which I am loading as integers from a database: val numsRDD = sqlContext .table(constants.SOURCE_DB + "." + IDS) .select("id") .distinct .map(row=>row.getInt(0)) This is the output of numsRDD : numsRDD.collect.foreach(println(_)) 643761 30673603 30736590 30773400 30832624 31104189 31598495 31723487 32776244 32801792 32879386 32981901 33469224 34213505 34709608 37136455 37260344 37471301 37573190 37578690 37582274 37600896 37608984 37616677