rcpp中%的糖

有%的Rcpp糖吗

例如，我在R中有以下陈述

y <- c('XA','XB','XC','XF','XK','XL','XM','XN','XO','XP','XS','XU','XW','XY', 'DF','DS','AS','XL','FG')
x <- ifelse(y %in% c("XA","XB","XC","XF","XK","XL","XM","XN","XO","XP","XS","XU","XW","XY"),"KCA","KUS")

我可以在Rcpp中使用，或者我如何在Rcpp中使用| |来避免错误？

请查看，以获取在运算符中糖化的

的示例。具体而言，这里给出的示例是：

CharacterVector A = CharacterVector::create("a", "b", "c", "c", "e", "b", "d");

CharacterVector B = CharacterVector::create("a", "b");

LogicalVector C = in(A, B);

在您的情况下，我们可以构建：

#include <Rcpp.h>

// [[Rcpp::export]]
Rcpp::CharacterVector my_classify(Rcpp::CharacterVector x,
                                  Rcpp::CharacterVector table,
                                  std::string true_cond = "KCA",
                                  std::string false_cond = "KUS") {

  Rcpp::CharacterVector out = Rcpp::CharacterVector(x.size());

  Rcpp::LogicalVector cond = in(x, table);

  for(unsigned int i = 0; i < cond.size(); ++i){
     if(cond[i]) {
       out[i] = true_cond;
     } else {
       out[i] = false_cond;
     }
  }

  return out;
}

我认为在%中执行<代码> %>的C++方式是 STD::FIN（）/<代码>，也可以参见，欢迎使用C++和字符串。您使用了一个
“
，字符串需要的是
”
。之后，您的
==
比较运算符代码应该可以工作。是的，在将
“
替换为
”
后，它就可以工作了，但为什么会这样呢？这是否意味着我不能在
std:：vector
中使用
”
？返回到C的语言定义。
“
用于单个字符，它也强制转换为整数，因此您看到了错误。所需字符串
“
。要在%

中真正复制

%，需要查看源代码。在%

中键入

%in%（周围带单引号）显示%

中的

%本身就是
匹配的糖。这是的主要功能。旧问题，但这也可以在中找到。doxygen文档缺少示例，很难导航。我不确定是否会链接到那里。肯定同意。同样，我发现示例（Dirk等人经常引用。）阅读起来很痛苦，需要更多的阅读。我认为这可能是一个限制，因为R目前采用的文档风格。但即使如此，我觉得它可能会更好，特别是当有这么多奇妙的功能可以让人的生活更轻松时（直到一个人进入std）
ambiguous overload for operator'=='(operand types are 'std::basic_string<char>' and 'int')

%in%

CharacterVector A = CharacterVector::create("a", "b", "c", "c", "e", "b", "d");

CharacterVector B = CharacterVector::create("a", "b");

LogicalVector C = in(A, B);

#include <Rcpp.h>

// [[Rcpp::export]]
Rcpp::CharacterVector my_classify(Rcpp::CharacterVector x,
                                  Rcpp::CharacterVector table,
                                  std::string true_cond = "KCA",
                                  std::string false_cond = "KUS") {

  Rcpp::CharacterVector out = Rcpp::CharacterVector(x.size());

  Rcpp::LogicalVector cond = in(x, table);

  for(unsigned int i = 0; i < cond.size(); ++i){
     if(cond[i]) {
       out[i] = true_cond;
     } else {
       out[i] = false_cond;
     }
  }

  return out;
}

x = c('XA','XB','XC','XF','XK','XL','XM','XN','XO','XP','XS',
      'XU','XW','XY', 'DF','DS','AS','XL','FG')
table = c("XA","XB","XC","XF","XK","XL","XM","XN",
          "XO","XP","XS","XU","XW","XY")
y = my_classify(x, table)
y
#>  [1] "KCA" "KCA" "KCA" "KCA" "KCA" "KCA" "KCA" "KCA" "KCA" "KCA" "KCA"
#> [12] "KCA" "KCA" "KCA" "KUS" "KUS" "KUS" "KCA" "KUS"