ARFF

Small utility for reading Attribute-Relation File Format (ARFF) data. For now, only a subset of
features is supported.

Supported:

• Numeric attributes
• String attributes
• Nominal attributes
• Date attributes (ISO-8601 UTC only)
• Weighted data
• Unicode

Not-supported:

• Relational attributes
• Sparse format

Example: Reader

import(
  "bytes"
  "fmt"
  "github.com/bsm/arff"
)
func main() {
    data, err := arff.Open("./testdata/weather.arff")
    if err != nil {
        panic("failed to open file: " + err.Error())
    }
    defer data.Close()
    for data.Next() {
        fmt.Println(data.Row().Values...)
    }
    if err := data.Err(); err != nil {
        panic("failed to read file: " + err.Error())
    }
}

Example: Writer

import (
  "bytes"
  "fmt"
  "github.com/bsm/arff"
)
func main() {
    buf := new(bytes.Buffer)
    w, err := arff.NewWriter(buf, &arff.Relation{
        Name:    "data relation",
        Attributes: []arff.Attribute{
            {Name: "outlook", DataType: arff.DataTypeNominal, NominalValues: []string{"sunny", "overcast", "rainy"}},
            {Name: "temperature", DataType: arff.DataTypeNumeric},
            {Name: "humidity", DataType: arff.DataTypeNumeric},
            {Name: "windy", DataType: arff.DataTypeNominal, NominalValues: []string{"TRUE", "FALSE"}},
            {Name: "play", DataType: arff.DataTypeNominal, NominalValues: []string{"yes", "no"}},
        },
    })
    if err != nil {
        panic("failed to create writer: " + err.Error())
    }
    if err := w.Append(&arff.DataRow{Values: []interface{}{"sunny", 85, 85, "FALSE", "no"}}); err != nil {
        panic("failed to append row: " + err.Error())
    }
    if err := w.Append(&arff.DataRow{Values: []interface{}{"overcast", 83, 86, "FALSE", "yes"}}); err != nil {
        panic("failed to append row: " + err.Error())
    }
    if err := w.Append(&arff.DataRow{Values: []interface{}{"rainy", 65, 70, "TRUE", "no"}}); err != nil {
        panic("failed to append row: " + err.Error())
    }
    if err := w.Close(); err != nil {
        panic("failed to close writer: " + err.Error())
    }
    fmt.Println(buf.String())
}