The nested loop is producing this error: Non-numeric argument to mathematical function
library(emdbook)

prev<-read.delim("shape.txt", header=T)
shape1<-prev$shape1
shape1<-as.numeric(shape1)
shape2<-prev$shape2
shape1<-as.numeric(shape2)

pvec <- seq(0, 1, length=298)

postvec<-data.frame(posterior=1:298)
dim(postvec)

for (i in 1:length(shape1))
{
    for (j in 1:length(shape2))
    {
    postvec[i]<- dbeta(pvec, shape1= shape1[i], shape2=shape2[j])
}
}

prev<-read.delim("shape.txt", header=T)
shape1<-prev$shape1
shape1<-as.numeric(shape1)
shape2<-prev$shape2
shape1<-as.numeric(shape2)

shape2<-as.numeric(shape2)