{'fraction_non_alphanumeric': 0.03600654664484452, 'fraction_numerical': 0.008183306055646482, 'mean_word_length': 5.6521739130434785, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Methods for Calculating the Correlation Coefficient

In 1885,Sir Francis Galton first defined the term"regression".A decade later,Karl Pearson developed the index that we still use to measure correlation,Pearson's r.The paper introduces 9 formulas that suggest different ways of thinking about this index,from algebraic,geometric,and trigonometric settings.We show that Pearson's r(or simple functions of r)may variously be thought of as a special type of mean,a special type of variance,the ratio of two means,the ratio of two variances,the slope of a line,the cosine of an angle,and the tangent to an ellipse.