2015年9月29日 · But note that this returns an Array and not an RDD. As for why the a.sample(false, 0.1) doesn't return the same sample size: it's because spark internally uses …

2014年7月17日 · Try using textFile.sample(false,fraction,seed) instead. takeSample will generally be very slow because it calls count() on the RDD. It needs to do this because otherwise it …

2017年1月22日 · In short, if you are sampling with replacement, you can get the same element in sample twice, and w/o replacement you can only get it once. So if your RDD has [Bob, Alice …

2015年7月14日 · As Justin and Wang mentioned it is not straight forward to get the size of RDD. We can just do a estimate. We can sample a RDD and then use SizeEstimator to get the size …

2017年6月4日 · I'd like to sample exactly one element from this RDD with probability proportional to value. In a naiive manner, this task can be accomplished as follows: pairs = …

2015年12月1日 · I only see the method sample() which takes a fraction as parameter. Setting this fraction to 1/numberOfRows leads to random results, where sometimes I won't get any row. …

2017年1月24日 · I currently need to randomly sample items in a RDD in Spark for k elements. I noticed that there is the takeSample method. The method signature is as follows. …

2014年9月18日 · // sample() does return an RDD so you may still want to collect() myHugeRDD.sample(true, 0.01).collect().foreach(a => println(a)) RDD.takeSample(): This is a …

2015年4月1日 · 2) You can use createDataFrame(rowRDD: RDD[Row], schema: StructType) as in the accepted answer, which is available in the SQLContext object. Example for converting …

rdd = sc.parallelize(numbers) rdd_sampled_1 = rdd.sample(False, 0.25) rdd_sampled_2 = rdd.sample(False, 0.25) rdd_sampled_3 = rdd.sample(False, 0.25) rdd_sampled_4 = …