无法从列

Question

我有大约280个人的数据和几个假的协变量，称为＆＃34;外国＆＃34; ＆＃34; prevgrad。＆＃34;数据如下所示：

    Name    Program foreign prevgrad    
    ******* *******   0       0 
    ******* *******   0       0 
    ******* *******   1       1 
    ******* *******   0       0 
    ******* *******   1       1 
    ******* *******   0       1 

每个人都属于一个程序集群A或B.我将数据分成两个子集A和B.我试图产生一个简单的最大似然估计，我试着做以下事情： / p>

    ##The density function for subset A
    PrA  <- function(u, piA0, piA1, piA2, piB0, piB1, piB2, z1, z2) {
   (1/sqrt(2*pi)*exp(-u^2/2))*3*exp(piA0+piA1*z1+piA2*z2+u  /(3*exp(piA0+piA1*z1+piA2*z2 + u)+5*exp(piB0+piB1*z1+piB2*z2))
    }

    logIntA  <- function(a0, a1, a2, b0, b1, b2, zee1, zee2) {
    log(integrate(function(u, piA0=a0, piA1=a1, piA2=a2, piB0=b0, piB1=b1, piB2=b2, z1=zee1, z2=zee2) PrA(u, piA0 = piA0, piA1 =piA1, piA2=piA2, piB0 = piB0, piB1 =piB1, piB2=piB2, z1=z1, z2=z2), lower=-10, upper=10)$integral)
    }

    #The density function for subset B
    PrB  <- function(u, piA0, piA1, piA2, piB0, piB1, piB2, z1, z2) {
    (1/sqrt(2*pi)*exp(-u^2/2))*5*exp(piB0+piB1*z1+piB2*z2)/(3*exp(piA0 + piA1*z1 +piA2*z2 + u)+5*exp(piB0+piB1*z1+piB2*z2))
    }

     logIntB  <- function(a0, a1, a2, b0, b1, b2, zee1, zee2) {
     log(integrate(function(u, piA0=a0, piA1=a1, piA2=a2, piB0=b0, piB1=b1, piB2=b2, z1=zee1, z2=zee2) PrB(u, piA0 = piA0, piA1 =piA1, piA2=piA2, piB0 = piB0, piB1 =piB1, piB2=piB2, z1=z1, z2=z2), lower=-10, upper=10)$integral)
    }

    ##The maximum likelihood statistic
    toMax2  <- function(t) {
    piA0=t[1]
    piA1=t[2]
    piA2=t[3]
    piB0=t[4]
    piB1=t[5]
    piB2=t[6]
    (sum(apply(studentsA[,c('foreign','prevgrad')],1, function(s) logIntA(piA0, piA1, piA2, piB0, piB1, piB2, s['foreign'], s['prevgrad'])))+sum(apply(students.AB[,c('foreign','prevgrad')],1, function(s) logIntB(piA0, piA1, piA2, piB0, piB1, piB2, s['foreign'], s['prevgrad']))))
   }

我无法在文档中找到相关的例子。＆＃39; apply。＆＃39;目前我收到错误＆＃34;数学函数的非数字参数。＆＃34;我无法弄清楚如何使z1等于“外国人”。并且z2等于prevgrad＆＃39;在每一行（即每个人）。

看起来像一个简单的修复，但你可能会告诉我，我是一个新手。我很感激任何建议（包括对代码的一般改进）。谢谢！