X-Git-Url: https://code.communitydata.science/cdsc_reddit.git/blobdiff_plain/2d425600a813e2fb280023a5a870b5660c36ea22..2740f55915d6ecca7c5cd800747d9687c4cd9245:/idf_comments.py?ds=sidebyside

diff --git a/idf_comments.py b/idf_comments.py
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+++ b/idf_comments.py
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+from pyspark.sql import functions as f
+from pyspark.sql import SparkSession
+
+spark = SparkSession.builder.getOrCreate()
+df = spark.read.parquet("/gscratch/comdata/users/nathante/reddit_tfidf_test.parquet_temp")
+
+max_subreddit_week_terms = df.groupby(['subreddit','week']).max('tf')
+max_subreddit_week_terms = max_subreddit_week_terms.withColumnRenamed('max(tf)','sr_week_max_tf')
+
+df = df.join(max_subreddit_week_terms, ['subreddit','week'])
+
+df = df.withColumn("relative_tf", df.tf / df.sr_week_max_tf)
+
+# group by term / week
+idf = df.groupby(['term','week']).count()
+
+idf = idf.withColumnRenamed('count','idf')
+
+# output: term | week | df
+#idf.write.parquet("/gscratch/comdata/users/nathante/reddit_tfidf_test_sorted_tf.parquet_temp",mode='overwrite',compression='snappy')
+
+# collect the dictionary to make a pydict of terms to indexes
+terms = idf.select('term').distinct()
+terms = terms.withColumn('term_id',f.monotonically_increasing_id())
+
+
+# print('collected terms')
+
+# terms = [t.term for t in terms]
+# NTerms = len(terms)
+# term_id_map = {term:i for i,term in enumerate(sorted(terms))}
+
+# term_id_map = spark.sparkContext.broadcast(term_id_map)
+
+# print('term_id_map is broadcasted')
+
+# def map_term(x):
+#     return term_id_map.value[x]
+
+# map_term_udf = f.udf(map_term)
+
+# map terms to indexes in the tfs and the idfs
+df = df.join(terms,on='term')
+
+idf = idf.join(terms,on='term')
+
+# join on subreddit/term/week to create tf/dfs indexed by term
+df = df.join(idf, on=['term_id','week','term'])
+
+# agg terms by subreddit to make sparse tf/df vectors
+df = df.withColumn("tf_idf",df.relative_tf / df.sr_week_max_tf)
+
+df = df.groupby(['subreddit','week']).agg(f.collect_list(f.struct('term_id','tf_idf')).alias('tfidf_maps'))
+ 
+df = df.withColumn('tfidf_vec', f.map_from_entries('tfidf_maps'))
+
+# output: subreddit | week | tf/df
+df.write.parquet('/gscratch/comdata/users/nathante/test_tfidf.parquet',mode='overwrite',compression='snappy')