CODEWITHSUNDEEP
r
Btzzzz
Btzzzz

Reputation: 143

Simplifying an R function with many variables

I'm trying to implement this model below:

enter image description here

However my code for it is quite messy due to all the Zs and Us, I'm looking for some coding tips to make my code as short and simple as possible? 

model = function(N,t1,t2){
  Z1 = rnorm(N,0,1)
  Z2 = rnorm(N,0,1)
  Z3 = rnorm(N,0,1)
  Z4 = rnorm(N,0,1)
  U1 = runif(N,0,1)
  U2 = runif(N,0,1)
  T = (U2+t2*U1)/(1+t2)
  X1 = (Z1+t1*U1)/(1+t1)
  X2= (Z2+t1*U1)/(1+t1)
  X3= (Z3+t1*U1)/(1+t1)
  X4= (Z4+t1*U1)/(1+t1)
  eps = rnorm(100,0,1)
  Y = 2*X1 + 3*T*X2 + X3*(T+1)^2+ 4*X4*sin(2*pi*T)/(2-2*sin(2*pi*T))+eps
  X = cbind(X1,X2,X3,X4)
  return(list(X = X, Y = Y))}

Upvotes: 1

Views: 53

Answers (1)

ThomasIsCoding
ThomasIsCoding

Reputation: 102181

Maybe the code below simplifies a bit

model = function(N,t1,t2){
  Z <- matrix(rnorm(4*N),nrow = N)
  U <- matrix(runif(2*N),nrow = N)
  W <- tcrossprod(U, rbind(c(t2, 1))) / (1+t2)
  X <- (Z + t1*U[,1])/(1+t1)
  eps <- rnorm(N)
  M <- cbind(2,3*W,(W+1)**2,4*sin(2*pi*W)/(2-sin(2*pi*W)))
  Y <- M*X + eps
  return(list(X = X, Y = Y))
}

Upvotes: 2

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