Recently I have used quantreg::rq() to estimate quantile regression. It returns Error when use summary(), it said:
Error in base::backsolve(r, x, k = k, upper.tri = upper.tri, transpose = transpose, : singular matrix in 'backsolve'. First zero in diagonal
Then I checked Error in summary quantreg backsolve this question and find the solution, which is set se method to iid : summary(df, se="iid) and it worked. But if I use stargazer() and set stargazer(df,rq.se="iid") it returns again the same error message :
Error in base::backsolve(r, x, k = k, upper.tri = upper.tri, transpose = transpose, : singular matrix in 'backsolve'. First zero in diagonal
Thus I want to ask is there a difference between summary() and stargazer() by calculating standard error?
Sorry I can not provide my data, because this happens only if I run the regressions with more than 4000 observations.