如何将用户定义的数据 C 结构用于 R 包
How to use a user-defined data C structure into an R package
这个最小的例子在我“获取”文件时编译：
/*
read_header.c
*/
#include <stdio.h>
#include <stdlib.h>
#include <RcppCommon.h>
typedef struct {
int my_data;
} MY_HEADER_INFO;
namespace Rcpp {
template <> SEXP wrap(const MY_HEADER_INFO& x);
}
#include <Rcpp.h>
namespace Rcpp {
template <>
SEXP wrap(const MY_HEADER_INFO& x) {
std::vector<std::string> names;
std::vector<SEXP> elements(1);
// do something with the elements and names
names.push_back("my_data");
elements[0] = Rcpp::wrap( x.my_data );
};
}
//' @export
// [[Rcpp::export]]
MY_HEADER_INFO read_header() {
MY_HEADER_INFO *header;
header = (MY_HEADER_INFO*)malloc(sizeof(MY_HEADER_INFO));
memset(header, 0, sizeof(MY_HEADER_INFO));
return *header;
}
当我尝试在 RStudio 中将它构建到一个包中（CMD + SHIFT + B）时，我收到以下很长的错误消息，它清楚地列出了问题是我的用户定义 return 结构, MY_HEADER_INFO:
描述
Package: myPackage
Type: Package
Title: What the Package Does (Title Case)
Version: 0.1.0
Depends: R (>= 4.0.0)
License: GPL-3
Encoding: UTF-8
LazyData: true
RoxygenNote: 7.1.0
Imports:
Rcpp
Suggests:
knitr,
rmarkdown,
testthat
VignetteBuilder: knitr
LinkingTo:
Rcpp
命名空间
# Generated by roxygen2: do not edit by hand
export(read_header)
我收到以下错误：
==> Rcpp::compileAttributes()
* Updated src/RcppExports.cpp
* Updated R/RcppExports.R
==> devtools::document(roclets = c('rd', 'collate', 'namespace'))
Updating myPackage documentation
Loading myPackage
Re-compiling myPackage
─ installing *source* package ‘myPackage’ ...
** using staged installation
** libs
clang++ -mmacosx-version-min=10.13 -std=gnu++11 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I'/Library/Frameworks/R.framework/Versions/4.0/Resources/library/Rcpp/include' -I/usr/local/include -fPIC -Wall -g -O2 -UNDEBUG -Wall -pedantic -g -O0 -fdiagnostics-color=always -c RcppExports.cpp -o RcppExports.o
RcppExports.cpp:9:1: error: unknown type name 'MY_HEADER_INFO'
MY_HEADER_INFO read_header();
^
1 error generated.
make: *** [RcppExports.o] Error 1
ERROR: compilation failed for package ‘myPackage’
─ removing ‘/private/var/folders/gl/jvj9b0xn34lgq6_h9370p8q80000gn/T/RtmpLKsw0o/devtools_install_1f333d54be59/myPackage’
Error: System command 'R' failed, exit status: 1, stdout + stderr:
E> * installing *source* package ‘myPackage’ ...
E> ** using staged installation
E> ** libs
E> clang++ -mmacosx-version-min=10.13 -std=gnu++11 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I'/Library/Frameworks/R.framework/Versions/4.0/Resources/library/Rcpp/include' -I/usr/local/include -fPIC -Wall -g -O2 -UNDEBUG -Wall -pedantic -g -O0 -fdiagnostics-color=always -c RcppExports.cpp -o RcppExports.o
E> RcppExports.cpp:9:1: error: unknown type name 'MY_HEADER_INFO'
E> MY_HEADER_INFO read_header();
E> ^
E> 1 error generated.
E> make: *** [RcppExports.o] Error 1
E> ERROR: compilation failed for package ‘myPackage’
E> * removing ‘/private/var/folders/gl/jvj9b0xn34lgq6_h9370p8q80000gn/T/RtmpLKsw0o/devtools_install_1f333d54be59/myPackage’
Stack trace:
1. base:::suppressPackageStartupMessages({ ...
2. base:::withCallingHandlers(expr, packageStartupMessage = function(c) tryInv ...
3. devtools::document(roclets = c("rd", "collate", "namespace"))
4. withr::with_envvar(r_env_vars(), roxygen2::roxygenise(pkg$path, ...
5. base:::force(code)
6. roxygen2::roxygenise(pkg$path, roclets, load_code = load_code)
7. roxygen2:::load_code(base_path)
8. pkgload::load_all(path, helpers = FALSE, attach_testthat = FALSE)
9. pkgbuild::compile_dll(path, quiet = quiet)
10. withr::with_makevars(compiler_flags(TRUE), assignment = "+=", ...
11. withr:::with_envvar(c(R_MAKEVARS_USER = makevars_file), { ...
12. base:::force(code)
13. base:::force(code)
14. pkgbuild:::install_min(path, dest = install_dir, components = "libs", ...
15. pkgbuild:::rcmd_build_tools("INSTALL", c(path, paste("--library=", ...
16. pkgbuild:::with_build_tools(callr::rcmd_safe(..., env = env, ...
17. callr::rcmd_safe(..., env = env, spinner = FALSE, show = FALSE, ...
18. callr:::run_r(options)
19. base:::with(options, with_envvar(env, do.call(processx::run, ...
20. base:::with.default(options, with_envvar(env, do.call(processx::run, ...
21. base:::eval(substitute(expr), data, enclos = parent.frame())
22. base:::eval(substitute(expr), data, enclos = parent.frame())
23. callr:::with_envvar(env, do.call(processx::run, c(list(bin, args = real_cmd ...
24. base:::force(code)
25. base:::do.call(processx::run, c(list(bin, args = real_cmdargs, ...
26. (function (command = NULL, args = character(), error_on_status = TRUE, ...
27. throw(new_process_error(res, call = sys.call(), echo = echo, ...
x System command 'R' failed, exit status: 1, stdout + stderr:
E> * installing *source* package ‘myPackage’ ...
E> ** using staged installation
E> ** libs
E> clang++ -mmacosx-version-min=10.13 -std=gnu++11 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I'/Library/Frameworks/R.framework/Versions/4.0/Resources/library/Rcpp/include' -I/usr/local/include -fPIC -Wall -g -O2 -UNDEBUG -Wall -pedantic -g -O0 -fdiagnostics-color=always -c RcppExports.cpp -o RcppExports.o
E> RcppExports.cpp:9:1: error: unknown type name 'MY_HEADER_INFO'
E> MY_HEADER_INFO read_header();
E> ^
E> 1 error generated.
E> make: *** [RcppExports.o] Error 1
E> ERROR: compilation failed for package ‘myPackage’
E> * removing ‘/private/var/folders/gl/jvj9b0xn34lgq6_h9370p8q80000gn/T/RtmpLKsw0o/devtools_install_1f333d54be59/myPackage’
Execution halted
Exited with status 1.
下面写到Rcpp_exports:
// Generated by using Rcpp::compileAttributes() -> do not edit by hand
// Generator token: 10BE3573-1514-4C36-9D1C-5A225CD40393
#include <Rcpp.h>
using namespace Rcpp;
// read_header
MY_HEADER_INFO read_header();
RcppExport SEXP _myPackage_read_header() {
BEGIN_RCPP
Rcpp::RObject rcpp_result_gen;
Rcpp::RNGScope rcpp_rngScope_gen;
rcpp_result_gen = Rcpp::wrap(read_header());
return rcpp_result_gen;
END_RCPP
}
static const R_CallMethodDef CallEntries[] = {
{"_myPackage_read_header", (DL_FUNC) &_myPackage_read_header, 0},
{NULL, NULL, 0}
};
RcppExport void R_init_myPackage(DllInfo *dll) {
R_registerRoutines(dll, NULL, CallEntries, NULL, NULL);
R_useDynamicSymbols(dll, FALSE);
}
但是，如果我尝试修改此文件，当我调用 CMD+SHIFT+B 时，所有内容都会被覆盖。
我为 return 标准数据类型（例如“std::vector”）的同一个包编写的其他 C 程序编译没有问题，无论是在控制台中“获取”代码还是在构建时他们打包成一个包。
我已经通读了 Rcpp 文档和相关的小插图（甚至还买了 Dirk 的书！），但我找不到如何告诉包构建器 MY_HEADER_INFO 的定义所在的位置。我如何告诉包编译器这个文件的定义在哪里？
谢谢！
这看起来像是一个并非完全不常见的问题的另一个例子，我们 确实 有一个非常简单的答案，但有些人比它应该知道的少。
简而言之，对于包 <pkg>（其中 <pkg> 是您的包名称的别名，小写或小写都可以。显然没有 < 或 >) 请这样的 struct （或者在 C++ 的情况下 class）或 typedef 或 ... 将定义放入文件 inst/include/<pkg>_types.h （将 <pkg> 替换为你的包裹名称）。
如果存在这样的文件，RcppExports.cpp 会自动包含它，您就可以开始了。
详细信息在 Rcpp Attributes vignette 中，也允许使用一些相关表格：
src/<pkg>_types.h
src/<pkg>_types.hpp
inst/include/<pkg>_types.h
inst/include/<pkg>_types.hpp
inst/include/<pkg>.h
但inst/include/<pkg>_types.h可能是最常用的一种。通过 src/ 使用它的一个例子是 src/RSQLite_types.h. On the other hand, an example of using it in inst/include/ is inst/include/RcppQuantuccia_types.h and another, much larger one in inst/include/RcppGSL_types.h.
这个最小的例子在我“获取”文件时编译：
/*
read_header.c
*/
#include <stdio.h>
#include <stdlib.h>
#include <RcppCommon.h>
typedef struct {
int my_data;
} MY_HEADER_INFO;
namespace Rcpp {
template <> SEXP wrap(const MY_HEADER_INFO& x);
}
#include <Rcpp.h>
namespace Rcpp {
template <>
SEXP wrap(const MY_HEADER_INFO& x) {
std::vector<std::string> names;
std::vector<SEXP> elements(1);
// do something with the elements and names
names.push_back("my_data");
elements[0] = Rcpp::wrap( x.my_data );
};
}
//' @export
// [[Rcpp::export]]
MY_HEADER_INFO read_header() {
MY_HEADER_INFO *header;
header = (MY_HEADER_INFO*)malloc(sizeof(MY_HEADER_INFO));
memset(header, 0, sizeof(MY_HEADER_INFO));
return *header;
}
当我尝试在 RStudio 中将它构建到一个包中（CMD + SHIFT + B）时，我收到以下很长的错误消息，它清楚地列出了问题是我的用户定义 return 结构, MY_HEADER_INFO:
描述
Package: myPackage
Type: Package
Title: What the Package Does (Title Case)
Version: 0.1.0
Depends: R (>= 4.0.0)
License: GPL-3
Encoding: UTF-8
LazyData: true
RoxygenNote: 7.1.0
Imports:
Rcpp
Suggests:
knitr,
rmarkdown,
testthat
VignetteBuilder: knitr
LinkingTo:
Rcpp
命名空间
# Generated by roxygen2: do not edit by hand
export(read_header)
我收到以下错误：
==> Rcpp::compileAttributes()
* Updated src/RcppExports.cpp
* Updated R/RcppExports.R
==> devtools::document(roclets = c('rd', 'collate', 'namespace'))
Updating myPackage documentation
Loading myPackage
Re-compiling myPackage
─ installing *source* package ‘myPackage’ ...
** using staged installation
** libs
clang++ -mmacosx-version-min=10.13 -std=gnu++11 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I'/Library/Frameworks/R.framework/Versions/4.0/Resources/library/Rcpp/include' -I/usr/local/include -fPIC -Wall -g -O2 -UNDEBUG -Wall -pedantic -g -O0 -fdiagnostics-color=always -c RcppExports.cpp -o RcppExports.o
RcppExports.cpp:9:1: error: unknown type name 'MY_HEADER_INFO'
MY_HEADER_INFO read_header();
^
1 error generated.
make: *** [RcppExports.o] Error 1
ERROR: compilation failed for package ‘myPackage’
─ removing ‘/private/var/folders/gl/jvj9b0xn34lgq6_h9370p8q80000gn/T/RtmpLKsw0o/devtools_install_1f333d54be59/myPackage’
Error: System command 'R' failed, exit status: 1, stdout + stderr:
E> * installing *source* package ‘myPackage’ ...
E> ** using staged installation
E> ** libs
E> clang++ -mmacosx-version-min=10.13 -std=gnu++11 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I'/Library/Frameworks/R.framework/Versions/4.0/Resources/library/Rcpp/include' -I/usr/local/include -fPIC -Wall -g -O2 -UNDEBUG -Wall -pedantic -g -O0 -fdiagnostics-color=always -c RcppExports.cpp -o RcppExports.o
E> RcppExports.cpp:9:1: error: unknown type name 'MY_HEADER_INFO'
E> MY_HEADER_INFO read_header();
E> ^
E> 1 error generated.
E> make: *** [RcppExports.o] Error 1
E> ERROR: compilation failed for package ‘myPackage’
E> * removing ‘/private/var/folders/gl/jvj9b0xn34lgq6_h9370p8q80000gn/T/RtmpLKsw0o/devtools_install_1f333d54be59/myPackage’
Stack trace:
1. base:::suppressPackageStartupMessages({ ...
2. base:::withCallingHandlers(expr, packageStartupMessage = function(c) tryInv ...
3. devtools::document(roclets = c("rd", "collate", "namespace"))
4. withr::with_envvar(r_env_vars(), roxygen2::roxygenise(pkg$path, ...
5. base:::force(code)
6. roxygen2::roxygenise(pkg$path, roclets, load_code = load_code)
7. roxygen2:::load_code(base_path)
8. pkgload::load_all(path, helpers = FALSE, attach_testthat = FALSE)
9. pkgbuild::compile_dll(path, quiet = quiet)
10. withr::with_makevars(compiler_flags(TRUE), assignment = "+=", ...
11. withr:::with_envvar(c(R_MAKEVARS_USER = makevars_file), { ...
12. base:::force(code)
13. base:::force(code)
14. pkgbuild:::install_min(path, dest = install_dir, components = "libs", ...
15. pkgbuild:::rcmd_build_tools("INSTALL", c(path, paste("--library=", ...
16. pkgbuild:::with_build_tools(callr::rcmd_safe(..., env = env, ...
17. callr::rcmd_safe(..., env = env, spinner = FALSE, show = FALSE, ...
18. callr:::run_r(options)
19. base:::with(options, with_envvar(env, do.call(processx::run, ...
20. base:::with.default(options, with_envvar(env, do.call(processx::run, ...
21. base:::eval(substitute(expr), data, enclos = parent.frame())
22. base:::eval(substitute(expr), data, enclos = parent.frame())
23. callr:::with_envvar(env, do.call(processx::run, c(list(bin, args = real_cmd ...
24. base:::force(code)
25. base:::do.call(processx::run, c(list(bin, args = real_cmdargs, ...
26. (function (command = NULL, args = character(), error_on_status = TRUE, ...
27. throw(new_process_error(res, call = sys.call(), echo = echo, ...
x System command 'R' failed, exit status: 1, stdout + stderr:
E> * installing *source* package ‘myPackage’ ...
E> ** using staged installation
E> ** libs
E> clang++ -mmacosx-version-min=10.13 -std=gnu++11 -I"/Library/Frameworks/R.framework/Resources/include" -DNDEBUG -I'/Library/Frameworks/R.framework/Versions/4.0/Resources/library/Rcpp/include' -I/usr/local/include -fPIC -Wall -g -O2 -UNDEBUG -Wall -pedantic -g -O0 -fdiagnostics-color=always -c RcppExports.cpp -o RcppExports.o
E> RcppExports.cpp:9:1: error: unknown type name 'MY_HEADER_INFO'
E> MY_HEADER_INFO read_header();
E> ^
E> 1 error generated.
E> make: *** [RcppExports.o] Error 1
E> ERROR: compilation failed for package ‘myPackage’
E> * removing ‘/private/var/folders/gl/jvj9b0xn34lgq6_h9370p8q80000gn/T/RtmpLKsw0o/devtools_install_1f333d54be59/myPackage’
Execution halted
Exited with status 1.
下面写到Rcpp_exports:
// Generated by using Rcpp::compileAttributes() -> do not edit by hand
// Generator token: 10BE3573-1514-4C36-9D1C-5A225CD40393
#include <Rcpp.h>
using namespace Rcpp;
// read_header
MY_HEADER_INFO read_header();
RcppExport SEXP _myPackage_read_header() {
BEGIN_RCPP
Rcpp::RObject rcpp_result_gen;
Rcpp::RNGScope rcpp_rngScope_gen;
rcpp_result_gen = Rcpp::wrap(read_header());
return rcpp_result_gen;
END_RCPP
}
static const R_CallMethodDef CallEntries[] = {
{"_myPackage_read_header", (DL_FUNC) &_myPackage_read_header, 0},
{NULL, NULL, 0}
};
RcppExport void R_init_myPackage(DllInfo *dll) {
R_registerRoutines(dll, NULL, CallEntries, NULL, NULL);
R_useDynamicSymbols(dll, FALSE);
}
但是，如果我尝试修改此文件，当我调用 CMD+SHIFT+B 时，所有内容都会被覆盖。 我为 return 标准数据类型（例如“std::vector”）的同一个包编写的其他 C 程序编译没有问题，无论是在控制台中“获取”代码还是在构建时他们打包成一个包。
我已经通读了 Rcpp 文档和相关的小插图（甚至还买了 Dirk 的书！），但我找不到如何告诉包构建器 MY_HEADER_INFO 的定义所在的位置。我如何告诉包编译器这个文件的定义在哪里？
谢谢！
这看起来像是一个并非完全不常见的问题的另一个例子，我们 确实 有一个非常简单的答案，但有些人比它应该知道的少。
简而言之，对于包 <pkg>（其中 <pkg> 是您的包名称的别名，小写或小写都可以。显然没有 < 或 >) 请这样的 struct （或者在 C++ 的情况下 class）或 typedef 或 ... 将定义放入文件 inst/include/<pkg>_types.h （将 <pkg> 替换为你的包裹名称）。
如果存在这样的文件，RcppExports.cpp 会自动包含它，您就可以开始了。
详细信息在 Rcpp Attributes vignette 中，也允许使用一些相关表格：
src/<pkg>_types.h
src/<pkg>_types.hpp
inst/include/<pkg>_types.h
inst/include/<pkg>_types.hpp
inst/include/<pkg>.h
但inst/include/<pkg>_types.h可能是最常用的一种。通过 src/ 使用它的一个例子是 src/RSQLite_types.h. On the other hand, an example of using it in inst/include/ is inst/include/RcppQuantuccia_types.h and another, much larger one in inst/include/RcppGSL_types.h.