NaN values with Pandas Spearman and Kendall correlations
I decided to abandon the complicated mathematics in favor of intuition. Because the NaN values arose only on arrays with constant values, it occurred to me that there is no relationship between it and the other data, so I set its Spearman and Kendall correlations to zero.
I am attempting to calculate Kendall's tau for a large matrix of data stored in a Pandas dataframe. Using the corr function, with method='kendall', I am receiving NaN for a row that has only one value (repeated for the length of the array). Is there a way to resolve it? The same issue happened with Spearman's correlation as well, presumably because Python doesn't know how to rank an array that has a single repeated value, which leaves me with Pearson's correlation -- which I am hesitant to use due to its normality and linearity assumptions.
Any advice is greatly appreciated!