[R] Help on the multivariate interpolation with R

Hello, I work on the Stochastic Frontier Analysis (SFA) and I am looking for a function in a R package which done the multivariate interpolation. My problem is: For all i=1, ..., n, I have values of (xi1, xi2, ..., xi7)in IR^7 and f(xi1, xi2, ..., xi7)in IR and I have also values of (x'i1, x'i2,

[R] Help on the multivariate interpolation with R

Hello, I work on the Stochastic Frontier Analysis (SFA) and I am looking for a function in a R package which done the multivariate interpolation. My problem is: For all i=1, ..., n, I have values of (xi1, xi2, ..., xi7)in IR^7 and f(xi1, xi2, ..., xi7)in R and I have also values of (x'i1, x'i2,