quantile regression+ dummy variable
问题 I used the quantreg package in R to compute the quantile regression model. In the model, dependent Variable(Y) is NAS_DELAY , and the independent variable(Xs) are SEANSON1TO4 , SEANSON2TO4 , SEANSON3TO4 . The model is: NAS_DELAY=aSEANSON1TO4+bSEANSON2TO4+cSEANSON3TO4+d The SEANSON1TO4 , SEANSON2TO4 , SEANSON3TO4 are dummy variables, 0 or 1. I use R to compute the intercept and other regression coefficient, but the result showed that "error in rq.fit.br(x,y,tau=tau,....)singular design matrix