--- a/cmd/soundingresults/main.go	Mon Sep 10 12:51:04 2018 +0200
+++ b/cmd/soundingresults/main.go	Mon Sep 10 15:10:31 2018 +0200
@@ -2,17 +2,13 @@
 
 import (
 	"bufio"
-	"compress/bzip2"
-	"compress/gzip"
 	"database/sql"
 	"flag"
 	"fmt"
-	"io"
 	"log"
 	"os"
 	"path/filepath"
 	"runtime"
-	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -58,85 +54,6 @@
 	depthReference string
 }
 
-func wrap(fname string, f io.Reader) (io.Reader, error) {
-
-	switch strings.ToLower(filepath.Ext(fname)) {
-	case ".gz":
-		return gzip.NewReader(f)
-	case ".bz2":
-		return bzip2.NewReader(f), nil
-	}
-
-	return bufio.NewReader(f), nil
-}
-
-type point3d struct {
-	x float64
-	y float64
-	z float64
-}
-
-func parseXYZ(fname string) ([]*point3d, error) {
-	f, err := os.Open(fname)
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-
-	r, err := wrap(fname, f)
-	if err != nil {
-		return nil, err
-	}
-
-	// Alloc in larger chunks to reduce pressure on memory management.
-	var chunk []point3d
-	alloc := func() *point3d {
-		if len(chunk) == 0 {
-			chunk = make([]point3d, 8*1024)
-		}
-		p := &chunk[0]
-		chunk = chunk[1:]
-		return p
-	}
-
-	var points []*point3d
-
-	s := bufio.NewScanner(r)
-	if s.Scan() { // Skip header line.
-		for line := 2; s.Scan(); line++ {
-			p := alloc()
-			text := s.Text()
-			// fmt.Sscanf(text, "%f,%f,%f") is 4 times slower.
-			idx := strings.IndexByte(text, ',')
-			if idx == -1 {
-				log.Printf("format error in line %d\n", line)
-				continue
-			}
-			if p.x, err = strconv.ParseFloat(text[:idx], 64); err != nil {
-				log.Printf("format error in line %d: %v\n", line, err)
-				continue
-			}
-			text = text[idx+1:]
-			if idx = strings.IndexByte(text, ','); idx == -1 {
-				log.Printf("format error in line %d\n", line)
-				continue
-			}
-			if p.y, err = strconv.ParseFloat(text[:idx], 64); err != nil {
-				log.Printf("format error in line %d: %v\n", line, err)
-				continue
-			}
-			text = text[idx+1:]
-			if p.z, err = strconv.ParseFloat(text, 64); err != nil {
-				log.Printf("format error in line %d: %v\n", line, err)
-				continue
-			}
-			points = append(points, p)
-		}
-	}
-
-	return points, s.Err()
-}
-
 func substituteName(fname, name string) string {
 	dir := filepath.Dir(fname)
 	info := filepath.Join(dir, "INFO.txt")

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cmd/soundingresults/points.go	Mon Sep 10 15:10:31 2018 +0200
@@ -0,0 +1,99 @@
+package main
+
+import (
+	"bufio"
+	"compress/bzip2"
+	"compress/gzip"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+type point3d struct {
+	x float64
+	y float64
+	z float64
+}
+
+type points3d []*point3d
+
+func parseXYZ(fname string) (points3d, error) {
+	f, err := os.Open(fname)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	r, err := wrap(fname, f)
+	if err != nil {
+		return nil, err
+	}
+	return readXYZ(r)
+}
+
+func wrap(fname string, f io.Reader) (io.Reader, error) {
+
+	switch strings.ToLower(filepath.Ext(fname)) {
+	case ".gz":
+		return gzip.NewReader(f)
+	case ".bz2":
+		return bzip2.NewReader(f), nil
+	}
+
+	return bufio.NewReader(f), nil
+}
+
+func readXYZ(r io.Reader) (points3d, error) {
+
+	// Alloc in larger chunks to reduce pressure on memory management.
+	var chunk []point3d
+	alloc := func() *point3d {
+		if len(chunk) == 0 {
+			chunk = make([]point3d, 8*1024)
+		}
+		p := &chunk[0]
+		chunk = chunk[1:]
+		return p
+	}
+
+	var points points3d
+
+	s := bufio.NewScanner(r)
+	if s.Scan() { // Skip header line.
+		for line := 2; s.Scan(); line++ {
+			p := alloc()
+			text := s.Text()
+			// fmt.Sscanf(text, "%f,%f,%f") is 4 times slower.
+			idx := strings.IndexByte(text, ',')
+			if idx == -1 {
+				log.Printf("format error in line %d\n", line)
+				continue
+			}
+			var err error
+			if p.x, err = strconv.ParseFloat(text[:idx], 64); err != nil {
+				log.Printf("format error in line %d: %v\n", line, err)
+				continue
+			}
+			text = text[idx+1:]
+			if idx = strings.IndexByte(text, ','); idx == -1 {
+				log.Printf("format error in line %d\n", line)
+				continue
+			}
+			if p.y, err = strconv.ParseFloat(text[:idx], 64); err != nil {
+				log.Printf("format error in line %d: %v\n", line, err)
+				continue
+			}
+			text = text[idx+1:]
+			if p.z, err = strconv.ParseFloat(text, 64); err != nil {
+				log.Printf("format error in line %d: %v\n", line, err)
+				continue
+			}
+			points = append(points, p)
+		}
+	}
+
+	return points, s.Err()
+}