Pass Pandas DataFrame to Scipy.optimize.curve_fit

[U1and0]

Also note that xdata should be a (k, M) array, where k is the number of predictor variables (i.e. columns) and M is the number of observations (i.e. rows). You should therefore transpose your input dataframe so that it is (4, M) rather than (M, 4), i.e. table[['A', 'B', 'C', 'D']].T.