在rcpp中按名称更改矢量元素

tab tab.names() == k ,在哪里 k

http://dirk.eddelbuettel.com/code/rcpp/Rcpp-quickref.pdf "foo" which

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

// [[Rcpp::export]]
IntegerVector fun(const arma::vec& assignment, int k) {

  // count number of peptides per protein
  IntegerVector tab = table(as<IntegerVector>(wrap(assignment)));
  CharacterVector all_proteins = tab.names(); 

  char kc = '0' + k;

  // what I need a working version of: 
  tab(kc) = 1;  // gets ignored, as does a [] version of the same thing.
  // or
  tab('0' + k) = 1; // also ignored

  int ki = which(all_proteins == kc); // gives me compile errors

  // extra credit
  // tab.names(k-1) = "-1";

  return tab;
}

/*** R
set.seed(23)
  x <- rpois(20, 5)
  k <- 5

  fun(x, k)

  # same thing in R:
  expected_output <- table(x)
  expected_output # before modification
#  x
#   3  4  5  6  7  9 10 12 
#   2  4  3  3  4  2  1  1 

  expected_output[as.character(k)] <- 1 # this is what I need help with
  expected_output

#  x
#   3  4  5  6  7  9 10 12 
#   2  4  1  3  4  2  1  1 

  # extra credit:
  names(expected_output)[as.character(k)] <- -1

*/

我还在学习RCPP,更重要的是,我还在学习如何阅读手册页面,并将正确的搜索词插入google/stackoverflow。我确信这是基本的东西(我对更好的方法是开放的——我现在想的是R程序员在初始问题上的方法,而不是C++程序员。)

arma::vec 用于代码的其他部分,我不想简单地显示这些部分—我意识到它在这里没有用处。我曾讨论过如何转换它,但基于我已经测试过的原则,我决定反对它,它是有效的,我最不想做的就是引入一个额外的bug…)