ANLY482 AY2017-18T2 Group30 LDA-Blog Post
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Data Source
To retrieve data from the company's posts, we used Scrapy, a fast and powerful open-sourced web-scraper to extract data from the blog. We collected data from the beginning of the first blog post, with the following information:
- Timestamp
- Author(s)
- Headline
- Category
- URL
- Tags
In order to analyse data from multiple sources (FB, Youtube, Instagram, Blog) - we need to to first join them together. One of the methods that we will be using is Latent Dirichlet Allocation (LDA), which is a natural language processing statistical model that allows us to create “topics” from a set of documents.
Reference: https://rstudio-pubs-static.s3.amazonaws.com/79360_850b2a69980c4488b1db95987a24867a.html
We will be using the following Python packages: pandas, nltk, stop_words and gensim.
Data Preparation
Data Cleaning
Tokenization
Tokenizing allows us to split sentences into words. The following Regex will match any characters other than a non-word.
from nltk.tokenize import RegexpTokenizer tokenizer = RegexpTokenizer(r'\w+')
Stop Words Certains words of a speech such as “for”, “as”, “the” are meaningless to generating topics, and as such, will be removed from the token list. We will be using the Python package, stop_words, which contains a predefined list of stop words.
from stop_words import get_stop_words
en_stop = get_stop_words('en')
Stemming Another NLP technique, stemming, allows us to reduce words that are similar such as “eating”, “eat”, “ate” to the stem “eat”. This is important to reduce the importance in the model. There are several algorithms but we will use the most commonly implemented version: Porter’s Stemming Algorithm.
from nltk.stem.porter import PorterStemmer p_stemmer = PorterStemmer()
Putting it all together, we will have a clean list of text tokens for analysis:
for i in docs:
raw = i.lower()
tokens = tokenizer.tokenize(raw)
stopped_tokens = [i for i in tokens if not i in en_stop]
stemmed_tokens = [p_stemmer.stem(i) for i in stopped_tokens]
texts.append(stemmed_tokens)
Exploratory Data Analysis
Refer to Report for Analysis
LDA Model
Refer to Report for Model Evaluation
