Hi,everyone I have two group data. x=c(0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9) y=c(1,2,3,4,5,6,7,8,9) and the confidence interval of y [0.9,1.1],[1.9,2.1],[2.9,3.1] [3.9,4.1],[4.9,5.1],[5.9,6.1] [6.9,7.1],[7.9,8.1],[8.9,9.1] How can I get the graph? as follows http://r.789695.n4.nabble.com/file/n3033259/%E6%9C%AA%E5%91%BD%E5%90%8D.jpg -- View this message in context: http://r.789695.n4.nabble.com/plot-graph-quantile-regression-for-panel-data-tp3033259p3033259.html Sent from the R help mailing list archive at Nabble.com.