What is causing this error? Coefficients not defined because of singularities
问题 I'm trying to find a model for my data but I get the message "Coefficients: (3 not defined because of singularities)" These occur for winter, large and high_flow I found this: https://stats.stackexchange.com/questions/13465/how-to-deal-with-an-error-such-as-coefficients-14-not-defined-because-of-singu which said it may be incorrect dummy variables, but I've checked that none of my columns are duplicates. when I use the function alias() I get: Model : S ~ A + B + C + D + E + F + G + spring +