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cdsc_reddit/author_cosine_similarity.py

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from pyspark.sql import functions as f
from pyspark.sql import SparkSession
from pyspark.sql import Window
import numpy as np
import pyarrow
import pandas as pd
import fire
from itertools import islice
from pathlib import Path
from similarities_helper import cosine_similarities
spark = SparkSession.builder.getOrCreate()
conf = spark.sparkContext.getConf()
# outfile = '/gscratch/comdata/users/nathante/test_similarities_500.feather'; min_df = None; included_subreddits=None; similarity_threshold=0;
def author_cosine_similarities(outfile, min_df = None, included_subreddits=None, similarity_threshold=0, topN=500, exclude_phrases=True):
'''
Compute similarities between subreddits based on tfi-idf vectors of author comments
included_subreddits : string
Text file containing a list of subreddits to include (one per line) if included_subreddits is None then do the top 500 subreddits
similarity_threshold : double (default = 0)
set > 0 for large numbers of subreddits to get an approximate solution using the DIMSUM algorithm
https://stanford.edu/~rezab/papers/dimsum.pdf. If similarity_threshold=0 we get an exact solution using an O(N^2) algorithm.
min_df : int (default = 0.1 * (number of included_subreddits)
exclude terms that appear in fewer than this number of documents.
outfile: string
where to output csv and feather outputs
'''
print(outfile)
print(exclude_phrases)
tfidf = spark.read.parquet('/gscratch/comdata/users/nathante/subreddit_tfidf_authors.parquet_test1/part-00000-107cee94-92d8-4265-b804-40f1e7f1aaf2-c000.snappy.parquet')
if included_subreddits is None:
included_subreddits = list(islice(open("/gscratch/comdata/users/nathante/cdsc-reddit/top_25000_subs_by_comments.txt"),topN))
included_subreddits = {s.strip('\n') for s in included_subreddits}
else:
included_subreddits = set(open(included_subreddits))
sim_dist, tfidf = cosine_similarities(tfidf, 'author', min_df, included_subreddits, similarity_threshold)
p = Path(outfile)
output_feather = Path(str(p).replace("".join(p.suffixes), ".feather"))
output_csv = Path(str(p).replace("".join(p.suffixes), ".csv"))
output_parquet = Path(str(p).replace("".join(p.suffixes), ".parquet"))
sim_dist = sim_dist.entries.toDF()
sim_dist = sim_dist.repartition(1)
sim_dist.write.parquet(str(output_parquet),mode='overwrite',compression='snappy')
spark.stop()
#instead of toLocalMatrix() why not read as entries and put strait into numpy
sim_entries = pd.read_parquet(output_parquet)
df = tfidf.select('subreddit','subreddit_id_new').distinct().toPandas()
df['subreddit_id_new'] = df['subreddit_id_new'] - 1
df = df.sort_values('subreddit_id_new').reset_index(drop=True)
df = df.set_index('subreddit_id_new')
similarities = sim_entries.join(df, on='i')
similarities = similarities.rename(columns={'subreddit':"subreddit_i"})
similarities = similarities.join(df, on='j')
similarities = similarities.rename(columns={'subreddit':"subreddit_j"})
similarities.write_feather(output_feather)
similarities.write_csv(output_csv)
return similarities
if __name__ == '__main__':
fire.Fire(term_cosine_similarities)