I'm running Python 2.7.11 from the Anaconda distribution (version 2.4.1) on a MacBook Pro running Mac OS X version 10.11.2 (El Capitan) I'm attempting to use numpy.ma.polyfit to perform a linear least square fit on some data I have. I'm running NumPy version 1.10.1. I've observed that in executing either numpy.polyfit or numpy.ma.polyfit I get the following traceback: /Users/user/anaconda/lib/python2.7/site-packages/numpy/lib/polynomial.py:594: RankWarning: Polyfit may be poorly conditioned warnings.warn(msg, RankWarning) Traceback (most recent call last): File "ComputeEnergy.py", line 132, in <module> coeffs, covar = np.ma.polyfit( xfit, yfit, fit_degree, rcond=rcondv, cov=True ) File "/Users/user/anaconda/lib/python2.7/site-packages/numpy/ma/extras.py", line 1951, in polyfit return np.polyfit(x, y, deg, rcond, full, w, cov) File "/Users/user/anaconda/lib/python2.7/site-packages/numpy/lib/polynomial.py", line 607, in polyfit return c, Vbase * fac ValueError: operands could not be broadcast together with shapes (6,6) (0,) I've attached a stripped down version of the Python program I'm running. Any suggestions? Sam Dupree.