C# SPSS SAV file reader and writer library

This library enables to read and write SPSS data files (.sav) on .net from and to a Stream. The library is UTF-8 safe.

It is available as a nuget package at https://www.nuget.org/packages/Curiosity.SPSS, and can be installed using the package manager or by issueing:

Install-Package Curiosity.SPSS

It's a fork of SPSS-.NET-Reader by fbiagi (based on spsslib-80132 by elmarj). Since forking we have added writing ability, solved many bugs, provided closer SPSS binary integration by following the PSPP provided SPSS format.

This library has been tested in production at @SIIS-Ltd, but mostly for write scenarios.

To read a data file:

// Open file, can be read only and sequential (for performance), or anything else
using (FileStream fileStream = new FileStream("data.sav", FileMode.Open, FileAccess.Read, FileShare.Read, 2048*10, 
                                              FileOptions.SequentialScan))
{
    // Create the reader, this will read the file header
    using (SpssReader spssDataset = new SpssReader(fileStream))
    {
        // Iterate through all the varaibles
        foreach (var variable in spssDataset.Variables)
        {
            // Display name and label
            Console.WriteLine("{0} - {1}", variable.Name, variable.Label);
            // Display value-labels collection
            foreach (KeyValuePair<double, string> label in variable.ValueLabels)
            {
                Console.WriteLine(" {0} - {1}", label.Key, label.Value);
            }
        }
        
        // Iterate through all data rows in the file
        foreach (var record in spssDataset.Records)
        {
            foreach (var variable in spssDataset.Variables)
            {
                Console.Write(variable.Name);
                Console.Write(':');
                // Use the corresponding variable object to get the values.
                Console.Write(record.GetValue(variable));
                // This will get the missing values as null, text with out extra spaces,
                // and date values as DateTime.
                // For original values, use record[variable] or record[int]
                Console.Write('\t');
            }
            Console.WriteLine("");
        }
    }
}

To write a data file:

// Create Variable list
var variables = new List<Variable>
{
    new Variable
    {
        Label = "The variable Label",
        ValueLabels = new Dictionary<double, string>
                {
                    {1, "Label for 1"},
                    {2, "Label for 2"},
                },
        Name = "avariablename_01",
        PrintFormat = new OutputFormat(FormatType.F, 8, 2),
        WriteFormat = new OutputFormat(FormatType.F, 8, 2),
        Type = DataType.Numeric,
        Width = 10,
        MissingValueType = MissingValueType.NoMissingValues
    },
    new Variable
    {
        Label = "Another variable",
        ValueLabels = new Dictionary<double, string>
                    {
                        {1, "this is 1"},
                        {2, "this is 2"},
                    },
        Name = "avariablename_02",
        PrintFormat = new OutputFormat(FormatType.F, 8, 2),
        WriteFormat = new OutputFormat(FormatType.F, 8, 2),
        Type = DataType.Numeric,
        Width = 10,
        MissingValueType = MissingValueType.OneDiscreteMissingValue
    }
};
// Set the one special missing value
variables[1].MissingValues[0] = 999;  

// Default options
var options = new SpssOptions();

using (FileStream fileStream = new FileStream("data.sav", FileMode.Create, FileAccess.Write))
{
    using (var writer = new SpssWriter(fileStream, variables, options))
    {
        // Create and write records
        var newRecord = writer.CreateRecord();
        newRecord[0] = 15d;
        newRecord[1] = 15.5d;
        writer.WriteRecord(newRecord);
        
        newRecord = writer.CreateRecord();
        newRecord[0] = null;
        newRecord[1] = 200d;
        writer.WriteRecord(newRecord);
        writer.EndFile();
    }
}

If you find any bugs or have issues, please open an issue on GitHub.

SAV file format

Binary description of *.sav file format is available here: http://www.gnu.org/software/pspp/pspp-dev/html_node/System-File-Format.html.