我很难在mlogit包中建模一个无选择的选项来估算联合数据的部分价值。我有来自600名受访者(respid)的选择数据。每个受访者选择3种假设产品(alt:A-C)和无选择选项(alt:D)。每个人都做了4次选择(问题)。
我准备以下数据:
data.test<-mlogit.data(data=robottest, choice="choice", shape="long", varying = 4:7, alt.var = "alt", alt.levels = paste("pos",1:4),id.var = "respid")
我收到以下错误消息,但它确实创建了数据。
Warning messages:
1: In mlogit.data(data = robottest, choice = "choice", shape = "long", :
variable alt exists and will be replaced
2: Setting row names on a tibble is deprecated.
我想用以下代码估算模型
m1<-mlogit(data=data.test, choice~apperance+features+brand+price, nests = list(Buy=c("A","B","C"), NoBuy=c("D")), unscaled = TRUE)
这不起作用,我收到错误说
Error in solve.default(H, g[!fixed]) :
system is computationally singular: reciprocal condition number = 4.91778e-24
有人知道如何解决这个问题吗?您是否会像我一样对无选择选项进行建模?任何帮助都不仅仅是欢迎!非常感谢你。
贝斯茨, 迈克尔