Question

我正在尝试使用.xlsx中的openxlsx包从R文件中读取值。简单来说，我需要写一行数据，然后填充一些必须在R中读回的输出单元格。我将分享一个例子来更好地解释这个问题。

.xlsx文件的初始状态：

我现在正在尝试向单元格写入新值：A2：A3 = c（“c”，5）。理想情况下，我期待A6 = 15

以下是使用的代码：

require(openxlsx)
path <- "C:/path_to_file/for_SO1.xlsx"
input_row <- c("c", 5)
# Load workbook; create if not existing
wb <- loadWorkbook(path)
# createSheet(wb, name = "1")
writeData(wb, 
          sheet = "Sheet1",
          x = data.frame(input_row),
          startCol=1,
          startRow=1
)  

data_IM <- read.xlsx(wb, 
                     sheet = "Sheet1",
                     rows = c(5,6),
                     cols = c(1))
# Save workbook
saveWorkbook(wb, file = path, overwrite = TRUE)

#> data_IM
#  output_row
#1          3

但我得到了初始值（3）。但是，如果我打开.xlsx文件，我可以看到驻留在那里的15：

无法读取此单元格的原因是什么？在写入文件并再次阅读之后我尝试保存它，但即便失败也是如此。由于XLConnect等的JAVA错误，openxlsx是我唯一的选择。

Answer 1

?read.xlsx

使用writeFormula写入Workbook对象的公式将无法获取由read.xlsx（）获取。这是因为只写了公式并在Excel中打开文件时进行评估。开幕使用Excel保存和关闭文件将解决此问题。

因此需要在Excel中打开文件然后保存，我可以验证这确实有效。但是，这可能不适合你。

XLConnect似乎具有所需的功能

# rjava can run out of memory sometimes, this can help.
options(java.parameters = "-Xmx1G")
library(XLConnect)

file_path = "test.xlsx"

input_row <- c("c", 5)

wb <- loadWorkbook(file_path, create=F)
writeWorksheet(wb, 1, startRow = 1, startCol = 1, data = data.frame(input_row))
setForceFormulaRecalculation(wb, 1, TRUE)
saveWorkbook(wb)

# checking
wb <- loadWorkbook(file_path, create=F)
readWorksheet(wb, 1)

Answer 2

文件https://cran.r-project.org/web/packages/openxlsx/openxlsx.pdf说

readbook.xlsx（）不会拾取工作簿对象。这是因为在Excel中打开文件时，仅编写公式并留待评估。使用Excel打开，保存和关闭文件将解决此问题。因此，如果您使用的是Windows，将以下文件vbs文件保存到例如opensaveexcel.vbs

Set objExcel = CreateObject("Excel.Application")
Set objWorkbook = objExcel.Workbooks.Open("D:\Book2.xlsx")
objWorkbook.Save
objWorkbook.Close 
objExcel.Quit
Set objExcel = Nothing
Set objWorkbook = Nothing

然后您可以编写R代码，因为单元格A4在Book1.xlsx中的公式为= A3 * 5

mywritexlsx(fname="d:/Book1.xlsx",data = 20,startCol = 1,startRow = 3)
system("cp d:\\Book1.xlsx d:\\Book2.xlsx")
system("cscript //nologo d:\\opensaveexcel.vbs")
tdt1=read.xlsx(xlsxFile = "d:/Book1.xlsx",sheet = "Sheet1",colNames = FALSE)
tdt2=read.xlsx(xlsxFile = "d:/Book2.xlsx",sheet = "Sheet1",colNames = FALSE)

以mywritexlsx的方式为我工作

mywritexlsx<-function(fname="temp.xlsx",sheetname="Sheet1",data,
                  startCol = 1, startRow = 1, colNames = TRUE, rowNames = FALSE)
{
  if(!file.exists(fname))
  {
   wb = openxlsx::createWorkbook()
   sheet = openxlsx::addWorksheet(wb, sheetname)
  }
  else
 {
   wb <- openxlsx::loadWorkbook(file =fname)
   if(!(sum(openxlsx::getSheetNames(fname)==sheetname)))
   sheet = openxlsx::addWorksheet(wb, sheetname)
   else
    sheet=sheetname
  }

  openxlsx::writeData(wb,sheet,data,startCol = startCol, startRow = startRow, 
          colNames = colNames, rowNames = rowNames)
  openxlsx::saveWorkbook(wb, fname,overwrite = TRUE)
}

openxlsx无法读取R

2 个答案: