Question

I’m trying to calculate the Pearson correlation correlation between every item in my list. I’m trying to get the correlations between data[0] and data[1], data[0] and data[2], and data[1] and data[2].

import scipy
from scipy import stats

data = [[1, 2, 4], [9, 5, 1], [8, 3, 3]]

def pearson(x, y):
    series1 = data[x]
    series2 = data[y]
    if x != y:
        return scipy.stats.pearsonr(series1, series2)

h = [pearson(x,y) for x,y in range(0, len(data))]

This returns the error TypeError: 'int' object is not iterable on h. Could someone please explain the error here? Thanks.

Answer 1

range will return you a list of int values while you are trying to use it like it returning you a tuple. Try itertools.combinations instead:

import scipy
from scipy import stats
from itertools import combinations

data = [[1, 2, 4], [9, 5, 1], [8, 3, 3]]

def pearson(x, y):
    series1 = data[x]
    series2 = data[y]
    if x != y:
        return scipy.stats.pearsonr(series1, series2)

h = [pearson(x,y) for x,y in combinations(len(data), 2)]

Or as @Marius suggested:

h = [stats.pearsonr(data[x], data[y]) for x,y in combinations(len(data), 2)]