l rank correlation coefficient `_ * `Spearman's rank correlation coefficient `_ Automatic data alignment: as with all pandas operations, automatic data alignment is performed for this method. ``corr()`` automatically considers values with matching indices. Examples -------- >>> def histogram_intersection(a, b): ... v = np.minimum(a, b).sum().round(decimals=1) ... return v >>> s1 = pd.Series([.2, .0, .6, .2]) >>> s2 = pd.Series([.3, .6, .0, .1]) >>> s1.corr(s2, method=histogram_intersection) 0.3 Pandas auto-aligns the values with matching indices >>> s1 = pd.Series([1, 2, 3], index=[0, 1, 2]) >>> s2 = pd.Series([1, 2, 3], index=[2, 1, 0]) >>> s1.corr(s2) -1.0 Ú