线性模型问题，代码出错

Outcome <- "XDD"
Finalvariables <- c("V", "qBDB", "PT", "APTT")
Formula <- formula(paste(paste(Outcome,"~", collapse=" "),

  •                      paste(Finalvariables, collapse=" + ")))

    model.final <- glm(Formula, dat=date,family=gaussian)
    lrm.final <- lrm(formula = model.final$formula, date = date, x=TRUE,y=TRUE)

Error in modelData(data, formula, weights = weights, subset = subset, :
no data found

这个为什么会出现这种错误啊，有偿3元，哈，学生没那么多自己悬赏问题