RCCP循环功能不dicard旧值

Question

我正在开发的RCCP和Rcpparmadillo一个交叉确认循环。同一回路完全在河的问题是，在RCPP循环的旧值不被丢弃。下面是一个非常简单的代码。该frmwC是一个很大的Rcpparmadillo功能，这给有R相同功能的相同结果时，迭代的次数是1（NR），但是当NR更前面的值被添加到新的一个，但我想保持onle最后一个在河发生的frmwC结果导出为列表

#include <RcppArmadillo.h>
// [[Rcpp::depends(RcppArmadillo)]]
using namespace Rcpp;
using namespace arma;

// [[Rcpp::export()]]
mat mult(const mat& X,const mat& Y, const mat& Xt, IntegerVector idx, int A, int nR) 
{
  uvec idx1 = as<uvec>(idx);
  List model;
  NumericMatrix Yc1;

  for (int i = 0; i <nR; i++)
  {
     mat X0 = X.rows(idx1);
     mat Y0 = Y.rows(idx1);
     mat X1 = subset_mat(X, idx);
     mat Y1 = subset_mat(Y, idx);
     // Rcout << X0;
     model = frmwC(X1,Y1,X0, A = A);
  }

  mat Yc = as<mat>(model("predYt"));
  return Yc;
}

下面是NR = 1的结果

X = matrix(runif(100, 1, 100),10,10)
Y = matrix(round(runif(10,1,100)))
Xt = matrix(runif(50,1,100),5,10)
Yt = matrix(round(runif(5, 1,100)))
idx = sample(size = 5, 0:9)
A = 10; nR = 1; nG = 2; Ix = matrix(0, A, ncol(X) + 1)

mult(X = X, Y = Y, Xt, idx = idx, A = A, nR = nR)

         [,1]     [,2]     [,3]     [,4]     [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 61.28675 80.15003 76.19408 73.11867 72.55760    0    0    0    0     0
[2,] 48.45832 43.98474 36.04582 33.73255 32.79945    0    0    0    0     0
[3,] 35.35432 32.30002 37.16849 39.35326 39.58430    0    0    0    0     0
[4,] 54.93001 48.29227 44.68769 53.29742 53.36127    0    0    0    0     0
[5,] 52.17147 64.95472 65.61675 76.79194 75.09447    0    0    0    0     0

结果为NR = 10

         [,1]     [,2]     [,3]     [,4]     [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 714.3052 733.1685 729.2125 726.1371 725.5760    0    0    0    0     0
[2,] 343.6533 339.1798 331.2408 328.9276 327.9945    0    0    0    0     0
[3,] 391.6130 388.5587 393.4271 395.6119 395.8430    0    0    0    0     0
[4,] 535.1815 528.5437 524.9391 533.5489 533.6127    0    0    0    0     0
[5,] 728.0217 740.8049 741.4669 752.6421 750.9447    0    0    0    0     0

并使用代码中的R版本

X0 = X[(idx+1),]
Y0 = Y[(idx+1),,drop = F]
X1 = X[-(idx+1),]
Y1 = Y[-(idx+1),,drop = F]
for (i in 1:10) {
  testR = frmwR(X = X1,Y = Y1, Xt = X0, Ix = Ix,A = A,Iss = Iss)
}

         [,1]     [,2]     [,3]     [,4]     [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 61.28675 80.15003 76.19408 73.11867 72.55760    0    0    0    0     0
[2,] 48.45832 43.98474 36.04582 33.73255 32.79945    0    0    0    0     0
[3,] 35.35432 32.30002 37.16849 39.35326 39.58430    0    0    0    0     0
[4,] 54.93001 48.29227 44.68769 53.29742 53.36127    0    0    0    0     0
[5,] 52.17147 64.95472 65.61675 76.79194 75.09447    0    0    0    0     0

只要IDX是相同的所有值，无论迭代应该是相同的。我怎样才能让RCPP丢弃从环先前的值，并保持最后只剩下？我的交叉验证比较复杂，我不能只是迭代次数除以值。谢谢你

Answer 1

我终于解决了问题，问题是在被宣布矩阵的intialisation的frmwC功能。起初，我并没有声明的初始值和导致该问题。现在，我宣布一个初始值，一切按预期工作（检查代码脚本下面。但是我不知道为什么会出现这种情况。如果有人能够详细说明这将是完美的

mat T = zeros(X.n_rows, A), P = zeros(X.n_cols, A), V = P, W = P,
    B = zeros(X.n_cols, Y.n_cols), Q = zeros(Y.n_cols, A), 
    Ys = zeros(X.n_rows, A-1),
    Yts = zeros(Xt.n_rows, A), Si = zeros(X.n_cols, X.n_cols), 
    Bt = zeros(X.n_cols, A),Xi = zeros(X.n_cols, X.n_rows),
    Res = zeros(A, 6), Cor = zeros(A,1);