====== Data Conversion ======

Use the Statistical Data Conversion app to convert a data file from one supported format to another. The maximum upload size is 20 MB. The app identifies the input format from the file extension.

===== Supported formats =====

^ Format ^ Input ^ Output ^
| SPSS | ''.sav'' | ''.sav'' |
| SAS data | ''.sas7bdat'' | ''.sas7bdat'' |
| SAS transport | ''.xpt'' | ''.xpt'' |
| Stata | ''.dta'' | ''.dta'' |
| Excel | ''.xls'', ''.xlsx'' | ''.xlsx'' |
| Comma-separated values | ''.csv'' | ''.csv'' |
| Text data | ''.txt'', ''.dat'' | ''.txt'' |

The app exports Excel files as ''.xlsx''; it does not export ''.xls''. Text output is tab-delimited.

===== Convert a file =====

  - [[https://webpower.psychstat.org/models/convertdata/|Open the Statistical Data Conversion app]].
  - Select a data file in one of the supported input formats.
  - Choose the format to convert to.
  - For CSV, TXT, or DAT input, indicate whether the first row contains variable names.
  - For CSV, TXT, or Excel output, choose how to handle value labels.
  - Select **Convert**.
  - When conversion finishes, review the reported row and variable counts and the data structure preview, then select the download link.

===== Options =====

^ Option ^ Description ^
| Variable names in first row | Choose **Yes** if the first row of CSV, TXT, or DAT input contains column names. Choose **No** if it contains data; the app will assign names such as V1 and V2. |
| Value labels | For CSV, TXT, or Excel output, choose **Keep numeric codes** to retain the underlying values, or **Replace codes with labels** to write available value labels as text. This setting does not affect other output formats. |

===== SAS format warning =====

**SAS data files (''.sas7bdat''):** These files are created with ''write_sas()''. The SAS file format is complex and undocumented, so this output is unreliable; in most cases, SAS will not read the file.

**For reliable SAS compatibility, choose SAS transport (''.xpt'').** ''write_xpt()'' produces files in the open SAS transport format, which SAS reliably reads. The transport format has limitations.

===== Troubleshooting =====

  * Confirm that the file extension matches the file’s actual format.
  * Check that the file is no larger than 20 MB.
  * For CSV, TXT, or DAT input, verify the variable-name setting matches the first row of the file.
  * If SAS cannot read an exported ''.sas7bdat'' file, convert the data to ''.xpt'' instead.