Question

我有一个使用Rcpp packgae在R函数内调用的C ++函数。 R函数接受inputDataFrame并使用C ++函数（也接受DataFrame）来计算药物量(A1)作为时间函数。然后，R返回inputDataFrame，其中包含已计算金额A1的已添加列。

我在为此功能制作Rpackage时遇到问题。我跟着RStudio instruction但是在构建软件包时遇到了错误。该错误位于RcppExport.cpp文件中，并指出'OneCompIVbolusCpp' was not declared in this scope。

以下是C ++和R函数的代码。当我处理示例数据帧时，它们在R中完美地工作。

Rfunction OneCompIVbolus_Rfunction.R：

library(Rcpp)
sourceCpp("OneCompIVbolusCppfunction.cpp")

OneCompIVbolusRCpp <- function(inputDataFrame){

  inputDataFrame$A1[inputDataFrame$TIME==0] <- inputDataFrame$AMT[inputDataFrame$TIME==0]
  OneCompIVbolusCpp( inputDataFrame )

  inputDataFrame
}

C ++函数OneCompIVbolusCppfunction.cpp：

#include <Rcpp.h>
#include <math.h>
#include <iostream>
using namespace Rcpp;
using namespace std;

// [[Rcpp::export]]
// input Dataframe from R
DataFrame OneCompIVbolusCpp(DataFrame inputFrame){

  //  Create vectors of each element used in function and for constructing output dataframe
  Rcpp::DoubleVector TIME = inputFrame["TIME"];
  Rcpp::DoubleVector AMT = inputFrame["AMT"];
  Rcpp::DoubleVector k10 = inputFrame["k10"];
  Rcpp::DoubleVector A1 = inputFrame["A1"];

  double currentk10, currentTime, previousA1, currentA1;

  // in C++ arrays start at index 0, so to start at 2nd row need to set counter to 1
  // for counter from 1 to the number of rows in input data frame
  for(int counter = 1; counter < inputFrame.nrows(); counter++){
  // pull out all the variables that will be used for calculation
    currentk10  = k10[ counter ];
    currentTime = TIME[ counter ] - TIME[ counter - 1];
    previousA1  = A1[ counter - 1 ];

    // Calculate currentA1
    currentA1 = previousA1*exp(-currentTime*currentk10);

    // Fill in Amounts and check for other doses
    A1[ counter ] = currentA1 + AMT[ counter ];

  } // end for loop
  return(0);
}

我在这里做错了什么提示？我该如何解决这个问题？

修改：

以下是在R：

中运行复合函数OneCompIVbolusRCpp的示例

library(plyr)
library(Rcpp)

source("OneCompIVbolus_Rfunction.R")

#-------------
# Generate df 
#-------------
#Set dose records:
dosetimes <- c(0,12)
#set number of subjects
ID <- 1:2
#Make dataframe
df <- expand.grid("ID"=ID,"TIME"=sort(unique(c(seq(0,24,1),dosetimes))),"AMT"=0,"MDV"=0,"CL"=2,"V"=10)
doserows <- subset(df, TIME%in%dosetimes)
#Dose = 100 mg, Dose 1  at time 0
doserows$AMT[doserows$TIME==dosetimes[1]] <- 100
#Dose 2 at 12
doserows$AMT[doserows$TIME==dosetimes[2]] <- 50
#Add back dose information
df <- rbind(df,doserows)
df <- df[order(df$ID,df$TIME,df$AMT),]       # arrange df by TIME (ascending) and by AMT (descending)
df <- subset(df, (TIME==0 & AMT==0)==F) # remove the row that has a TIME=0 and AMT=0
df$k10 <- df$CL/df$V
#-------------
# Apply the function 
#-------------
simdf <- ddply(df, .(ID), OneCompIVbolusRCpp)

Answer 1

您可能只是订购错误。而不是

// [[Rcpp::export]]
// input Dataframe from R
DataFrame OneCompIVbolusCpp(DataFrame inputFrame){
   // ...

DO

// input Dataframe from R
// [[Rcpp::export]]
DataFrame OneCompIVbolusCpp(DataFrame inputFrame){
   // ...

因为[[Rcpp::export]]标记必须直接出现在它导出的函数之前。

使用R / C ++函数构建Rpackage时出现问题

1 个答案: