Converts a vectorform distance vector to a squareform distance matrix, and viceversa.
Parameters :  X : ndarray


Returns :  Y : ndarray
force : str, optional
checks : bool, optional

Notes
v = squareform(X)
Given a square dbyd symmetric distance matrix X, v=squareform(X) returns a d * (d1) / 2 (or ${n choose 2}$) sized vector v.
v[{n choose 2}{ni choose 2} + (ji1)] is the distance between points i and j. If X is nonsquare or asymmetric, an error is returned.
X = squareform(v)
Given a d*d(1)/2 sized v for some integer d>=2 encoding distances as described, X=squareform(v) returns a d by d distance matrix X. The X[i, j] and X[j, i] values are set to v[{n choose 2}{ni choose 2} + (ju1)] and all diagonal elements are zero.