Question

我想通过使用包括rmarkdown :: render函数的for循环并包含带条件的多个参数（参数），使用R创建多个.html。在这种情况下，如何设置多个参数？

我尝试了以下无效的代码。

Rmd模板示例：

 Dim con As ADODB.Connection
 Dim oResult As ADODB.Recordset


 Private Sub createDbConnection()
 On Error Resume Next
 Set con = New ADODB.Connection
 con.CommandTimeout = 180
 con.Open anyconnection ‘ any connection

End Sub

Private Sub closeDbConnection()
On Error Resume Next
con.Close
End Sub



Private Sub execsql(ByVal Sqlstr As String, ByVal Destination As Range)
Dim oResult As ADODB.Recordset
Set oResult = New ADODB.Recordset
createDbConnection

execsql = 0

With oResult
    .ActiveConnection = con
    .Open Sqlstr
   .Destination.CopyFromRecordset
 End With
'Destination.CopyFromRecordset oResult
 execsql = 1
 closeDbConnection
 End Sub

 Sub runsql()
 Dim Sqlstr
 Dim Destination
Sqlstr = ThisWorkbook.Sheets("SQL").Range("f3").Value
Destination = ThisWorkbook.Sheets("SQL").Range("f11")    
execsql Sqlstr, Destination

End Sub

创建的for循环用于使用不同的参数从Rmd模板生成html：

---
title: "The ranking of `r params$word` companies"
output: distill::distill_article
params:
  country: "USA"
  word: "American"
  pays: "the United States"
---

Figure 1. Number of businesses in `r params$pays`      

```{r}
dataGraph1 <- filter(dataGraph7, country==params$country)
plot(dataGraph1)
```
It is interesting to observe the progress of those `r params$word` businesses.

错误：

# Directory containing input (and output) files
directory <- "~/thelink"

for (country in c("Canada", "USA", "France", "Germany", "UK", "Japan")) {
  if (country == "Canada"){
    word <- "Canadian"
    pays <- "Canada"
  } else if (country == "USA"){
    word <- "American"
    pays <- "the United States"
  } else if (country == "Germany") {
    word <- "German"
    pays <- "Germany"
  } else if (country == "France") {
    word <- "French"
    pays <- "France"
  } else if (country == "UK") {
    word <- "British"
    pays <- "The United Kingdom"
  } else (country == "Japan") {
    word <- "Japanese"
    pays <- "Japan"
  }
  input <- paste0(directory, "/", "iri2015template", ".Rmd")
  output <- paste0(directory, "/","iri2015", country, ".html")
  try(rmarkdown::render(input, params = list(country = country, word = word, pays = pays), output_file = output))
}

我希望for循环产生的是一个名为iri2015USA.html的html，当country == USA且其他参数为word == American并支付== United States时。

当国家==加拿大，其他参数为单词==加拿大，并支付==加拿大时，它将产生一个名为iri2015Canada.html的html。

等

非常感谢。

Answer 1

请考虑与其他语言（Java，C＃，C ++，PHP，Perl）类似使用的switch：

for (country in c("Canada", "USA", "France", "Germany", "UK", "Japan")) {
  switch (country,           
          "Canada" = {
             word <- "Canadian"
             pays <- "Canada"
          },    
          "USA" = {
             word <- "American"
             pays <- "the United States"
          }, 
          "Germany" = {
             word <- "German"
             pays <- "Germany"
          }, 
           "France" = {
             word <- "French"
             pays <- "France"
          },
          "UK" = {
             word <- "British"
             pays <- "The United Kingdom"
          },
          "Japan" = {
             word <- "Japanese"
             pays <- "Japan"
          })

  input <- paste0(directory, "/", "iri2015template", ".Rmd")
  output <- paste0(directory, "/","iri2015", country, ".html")

  tryCatch(rmarkdown::render(input, 
                             params = list(country = country, word = word, pays = pays), 
                             output_file = output)
           , error = function(e) print(e)
  )              
}

Answer 2

countries <-  c("Germany",
                "France",
                "UK",
                "USA",
                "Japan",
                "Canada")

for (country in countries) {
  nationality <- switch (country,
                         "USA" = "American",
                         "France" = "French",
                         "Germany" = "German",
                         "UK" = "British",
                         "Japan" = "Japanese",
                         "Canada" = "Canadian")
  name <- switch (country,
                  "USA" = "the United States",
                  "France" = "France",
                  "Germany" = "Germany",
                  "UK" = "the United Kingdom",
                  "Japan" = "Japan",
                  "Canada" = "Canadian")
  input <- paste0(directory, "/", "iri2015template", ".Rmd")
  output <- paste0(directory, "/","iri2015", country, ".html")
  rmarkdown::render(input, params = list(country = country, nationality = nationality, name = name), output_file = output)
}

Answer 3

甚至考虑Map（包装到mapply），这是通过等长向量（即数据帧的列）的元素级循环，该等长向量无需调整switch即可缩放至数据if代码。

country_df <- data.frame(
     country = c("Germany", "France", "UK", "USA", "Japan", "Canada"),
     nationality = c("German", "French", "British", "American", "Japanese", "Canadian"),
     names = c("Germany", "France", "the United Kingdom", 
               "the United States", "Japan", "Canada")
)

# USER-DEFINED FUNCTION OF MULTIPLE ARGS
html_build <- function(country, nationality, names) {    
  input <- paste0(directory, "/", "iri2015template", ".Rmd")
  output <- paste0(directory, "/","iri2015", country, ".html")

  rmarkdown::render(input, 
                    params = list(country = country, 
                                  nationality = nationality, 
                                  name = names), 
                    output_file = output)
}

# ELEMENT WISE (LOOP-HIDING) CALL
Map(html_build, country_df$country, country_df$nationality, country_df$names)

# with(country_df, Map(html_build, country, nationality, names))           # LESS WORDY

R中for循环中具有渲染功能的多个参数

3 个答案: