data<-read.table(file="data.txt",header=TRUE)

library(Formula)

library(plm)

library(pgmm)

gmm<-pgmm(dynformula(y~log(x2)+x3+x4+x5+x6+x7,lag=list(1,0,0,0,0,0,0),log=FALSE),p,effect="twoways",model="onestep",gmm.inst=~y,lag.gmm=list(c(1,3)))

gmm<-pgmm(dynformula(y~log(x2)+x3+x4+x5+x6+x7,lag=list(1,0,0,0,0,0,0),log=FALSE),data,effect="twoways",model="onestep",gmm.inst=~y,lag.gmm=list(c(1,3)))

> summary（gmm）

报错：错误于!class_ind : 参数种类不对

求助各位大神~~~