56 lines
1.1 KiB
Go
56 lines
1.1 KiB
Go
package main
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import (
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"encoding/csv"
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"fmt"
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"io"
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"strconv"
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)
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type statsFunc func(data []float64) float64
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func sum(data []float64) float64 {
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sum := 0.0
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for _, v := range data {
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sum += v
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}
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return sum
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}
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func avg(data []float64) float64 {
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return sum(data) / float64(len(data))
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}
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func csv2float(r io.Reader, column int) ([]float64, error) {
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cr := csv.NewReader(r)
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// set this to reuse the same slice for each read
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// operation to reduce the memory allocation
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cr.ReuseRecord = true
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if column < 1 {
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return nil, fmt.Errorf("%w: please provide a valid column number", ErrInvalidColumn)
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}
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column--
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var data []float64
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for i := 0; ; i++ {
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row, err := cr.Read()
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if err == io.EOF {
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break
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}
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if err != nil {
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return nil, fmt.Errorf("cannot read data from file: %w", err)
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}
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if i == 0 {
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continue
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}
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if len(row) <= column {
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return nil, fmt.Errorf("%w: File has only %d columns", ErrInvalidColumn, len(row))
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}
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v, err := strconv.ParseFloat(row[column], 64)
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if err != nil {
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return nil, fmt.Errorf("%w: %s", ErrNotNumber, err)
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}
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data = append(data, v)
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}
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return data, nil
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}
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