ReadStata13.Rmd

---
title: "Read Stata 13 data file"
author: "Benjamin Chan (chanb@ohsu.edu)"
date: "Thursday, September 18, 2014"
output:
  html_document:
    keep_md: yes
---

Define the function `readStata13`.

```{r}
readStata13 <- function (fIn) {
  if (Sys.info()["nodename"] == "CHSE") {
    top <- file.path("E:", "Share")
    } else {
      top <- file.path("E:")
      }
  pathApp <- file.path(top, "Applications")
  # Convert from Stata version 13 to version 12
  # Can't use StatTransfer 11; need to convert using Stata 13
  # Create a temporary do file to do this
  tempFileName <- tempfile()
  fOut <- paste0(tempFileName, ".dta")
  fDo <- paste0(tempFileName, ".do")
  fLog <- paste0(tempFileName, ".log")
  lines <- newline(NULL, "capture log close")
  lines <- newline(lines, paste("log using", fLog, ", replace"))
  lines <- newline(lines, paste("use", paste0("\"", fIn, "\""), ", clear"))
  lines <- newline(lines, paste("saveold", paste0("\"", fOut, "\""), ", replace"))
  lines <- newline(lines, "")
  cat(lines, file=fDo)
  # Run Stata in batch mode
  cmd <- paste(file.path(pathApp, "Stata13", "StataMP-64.exe"), "/e do", paste0("\"", fDo, "\""))
  system(cmd, invisible=FALSE)
  # Check the log
  show(readLines(fLog))
  # Then use the foreign package to read the converted version 12 dta file
  require(foreign)
  D <- read.dta(fOut)
  D
}
```

Define some helper functions.

```{r}
newline <- function (lines, lineToAdd) {
  lines <- paste(lines, lineToAdd, sep="\n")
  lines
}
```

Set file paths.

```{r}
if (Sys.info()["nodename"] == "CHSE") {
  top <- file.path("E:", "Share")
} else {
  top <- file.path("E:")
}
pathStata <- file.path(top, "Other", "Some code by John", "CCO analyses", "3 Final Data Sets")
```

Read this Stata 13 file.

```{r}
f <- file.path(pathStata, "quarterly_mcaid_commercial.dta")
```

Try reading the Stata 13 file **without converting** to Stata 12.

```{r, error=TRUE}
require(foreign)
D <- read.dta(f)
```

Try reading the Stata 13 file **after converting** to Stata 12.

```{r}
D <- readStata13(f)
```

Check the returned data frame.

```{r}
str(D)
```