Optional manually defined power scale

Makefile

@@ -40,6 +40,6 @@ lint:
 	golint .
 
 clean:
-	rm -f build
-	rm -rf internal/resources
+	- rm -r build
+	- rm -rf internal/resources
 

README.md

@@ -1,9 +1,8 @@
 # rtl-gopow
-Render tables from rtl_power to a nice heat map
-Here is an render of rtl_power tool scanning 80-90 MHz during 2.5 hours moving in a car. ![80-90 MHz](http://i.imgur.com/knkzLXO.jpg).
+Render tables from rtl_power to a nice heat map. Faster and easier to use than other tools, gopow does not require a scripting enviroment, dependencies or development enviroment to run. Just download the binary and execute. At the same time gopow offers 2-3.6 times the performance compared to script based tools, depending on input file.
 
-# Availability
-Since Go is easy to cross compile, this tool can be easily distributed as a binary without any dependencies. You'll find it under Releases here on github. The following platforms are avalible as a ready to run binary file:
+## Availability
+Since Go is easy to cross compile, this tool can be easily distributed as a binary without any dependencies. You'll find it under [Releases](https://github.com/dhogborg/rtl-gopow/releases) here on github. The following platforms are avalible as a ready to run binary file:
 
 * OS X (x64)
 * Linux (x64)
@@ -11,9 +10,37 @@ Since Go is easy to cross compile, this tool can be easily distributed as a bina
 * Linux (arm7)
 * Windows (x64)
 
+https://github.com/dhogborg/rtl-gopow/releases
+
+## Building
+(only needed if making changes to the source, otherwise you can download a [release binary](https://github.com/dhogborg/rtl-gopow/releases))
+
+### Install tooling
+`make setup` will install [go-bindata](https://github.com/jteeuwen/go-bindata) which is needed to build the resources. Make sure $GOPATH/bin is in your $PATH so your shell can find the tool.
+
+### Make resources
+`make resources` will compile rtl-gopow/resources/ to rtl-gopow/internal/resources/resources.go. This file is disposable and will re-generate on every build. 
+
+### Make build
+Every platform has it's own make command. 
+* `make build_darwin`
+* `make build_linux`
+* `make build_arm5`
+* `make build_arm7`
+* `make build_win`
+
+All commands will compile a binary to rtl-gopow/build/gopow[.exe] and create a distributable zip file. For more info on cross compilation see [this document](http://dave.cheney.net/2013/07/09/an-introduction-to-cross-compilation-with-go-1-1).
+
+`make all` will build all platforms and create zip files in rtl-gopow/build/ and then remove the executable files.
+
+### go build/run
+Before runnning `go build *.go` or `go run *.go` make sure the resources has been generated by `make resources`. 
+
 ## Performance
 A render of a 600 MB csv file takes about 2 minutes on a 2,4 GHz Intel Core i5. There is still lots of room for improvement on that though. Memory usage is quite horrid.
 
+Compared to script based tools gopow will run more than 2x faster for smaller files, and more than 3x faster for bigger files.
+
 ## Options
 ```
 GLOBAL OPTIONS:
@@ -26,3 +53,6 @@ GLOBAL OPTIONS:
    --version, -v    print the version
 
 ```
+
+## Demo
+Here is an render of rtl_power tool scanning 80-90 MHz during 2.5 hours moving in a car. ![80-90 MHz](http://i.imgur.com/knkzLXO.jpg).

gopow.go

@@ -14,7 +14,7 @@ func main() {
 	app := cli.NewApp()
 	app.Name = "RTL GoPow"
 	app.Usage = "Render a rtl_power CSV output as waterfall image"
-	app.Version = "0.0.1"
+	app.Version = "0.0.3"
 	app.Author = "github.com/dhogborg"
 	app.Email = "d@hogborg.se"
 
@@ -68,6 +68,16 @@ func main() {
 			Value: "png",
 			Usage: "Output file format, default png [png,jpeg]",
 		},
+		cli.Float64Flag{
+			Name:  "max-power",
+			Value: 0,
+			Usage: "Define a manual maximum power (format nn.n)",
+		},
+		cli.Float64Flag{
+			Name:  "min-power",
+			Value: 0,
+			Usage: "Define a manual minimum power (format nn.n)",
+		},
 		cli.BoolFlag{
 			Name:  "verbose",
 			Usage: "Enable more verbose output",

internal/gopow/gopow.go

@@ -13,11 +13,17 @@ import (
 	"github.com/dustin/go-humanize"
 )
 
+const (
+	PowerConfigAuto = -9813
+)
+
 type RunConfig struct {
 	InputFile   string
 	OutputFile  string
 	Format      string
 	Annotations bool
+	MaxPower    float64
+	MinPower    float64
 }
 
 type GoPow struct {
@@ -33,6 +39,15 @@ func NewGoPow(c *cli.Context) (*GoPow, error) {
 		OutputFile:  c.String("output"),
 		Format:      c.String("format"),
 		Annotations: !c.Bool("no-annotations"),
+		MaxPower:    c.Float64("max-power"),
+		MinPower:    c.Float64("min-power"),
+	}
+
+	if !c.IsSet("max-power") {
+		config.MaxPower = PowerConfigAuto
+	}
+	if !c.IsSet("min-power") {
+		config.MinPower = PowerConfigAuto
 	}
 
 	if config.InputFile == "" {
@@ -66,10 +81,20 @@ func NewGoPow(c *cli.Context) (*GoPow, error) {
 
 func (g *GoPow) Render() error {
 
+	conf := &RenderConfig{}
+
+	if g.config.MaxPower != PowerConfigAuto {
+		conf.MaxPower = &g.config.MaxPower
+	}
+
+	if g.config.MinPower != PowerConfigAuto {
+		conf.MinPower = &g.config.MinPower
+	}
+
 	log.Debug("staring render")
 	g.timestamp = time.Now()
 
-	table, err := NewTable(g.config.InputFile)
+	table, err := NewTable(g.config.InputFile, conf)
 	if err != nil {
 		return err
 	}
@@ -77,7 +102,7 @@ func (g *GoPow) Render() error {
 	g.image = table.Image()
 
 	for y, row := range table.Rows {
-		for x, _ := range row.Samples {
+		for x := range row.Samples {
 			g.image.Set(x, y, table.ColorAt(x, y))
 		}
 	}

internal/gopow/line.go

@@ -1,6 +1,7 @@
 package gopow
 
 import (
+	"math"
 	"strconv"
 	"strings"
 	"time"
@@ -108,9 +109,9 @@ func (l *LineComplex) AddSamples(line *LineComplex) {
 
 func (l *LineComplex) HighSample() float64 {
 
-	high := float64(-99999)
+	high := float64(math.MaxFloat64 * -1)
 	for _, sample := range l.Samples {
-		if sample > high {
+		if sample > high && !math.IsInf(sample, 0) {
 			high = sample
 		}
 	}
@@ -119,9 +120,10 @@ func (l *LineComplex) HighSample() float64 {
 }
 
 func (l *LineComplex) LowSample() float64 {
-	low := float64(99999)
+
+	low := float64(math.MaxFloat64)
 	for _, sample := range l.Samples {
-		if sample < low {
+		if sample < low && !math.IsInf(sample, 0) {
 			low = sample
 		}
 	}

internal/gopow/table.go

@@ -1,6 +1,7 @@
 package gopow
 
 import (
+	"bytes"
 	"image"
 	"image/color"
 	"io/ioutil"
@@ -16,12 +17,10 @@ import (
 
 type TableComplex struct {
 	File   string // our input file
+	Config *RenderConfig
 
 	Rows []*LineComplex
 
-	Min float64 // minimum power value, used for color rendering
-	Max float64 // maximum dito
-
 	Bins         int // horizontal slots, columns, bandwidth
 	Integrations int // vertical slots, rows
 
@@ -32,11 +31,19 @@ type TableComplex struct {
 	TimeEnd   *time.Time
 }
 
-func NewTable(file string) (*TableComplex, error) {
+// RenderConfig overrides automaticly calculated defaults
+type RenderConfig struct {
+	MinPower *float64 // minimum power value, used for color rendering
+	MaxPower *float64 // maximum dito
+}
+
+func NewTable(file string, conf *RenderConfig) (*TableComplex, error) {
 
 	log.Debug("creating table")
 
-	t := &TableComplex{}
+	t := &TableComplex{
+		Config: conf,
+	}
 
 	err := t.Load(file)
 	if err != nil {
@@ -69,17 +76,16 @@ func (t *TableComplex) Load(file string) error {
 
 func (t *TableComplex) parseBuffer(filebuffer []byte) []*LineComplex {
 
-	t.Max = float64(math.MaxFloat64 * -1)
-	t.Min = float64(math.MaxFloat64)
+	var max = float64(math.MaxFloat64 * -1)
+	var min = float64(math.MaxFloat64)
 
-	block := string(filebuffer)
-	lines := strings.Split(block, "\n")
+	lines := bytes.Split(filebuffer, []byte("\n"))
 
 	table := map[string][]*LineComplex{}
 
 	for _, l := range lines {
 
-		cells := strings.Split(l, ",")
+		cells := strings.Split(string(l), ",")
 		line := NewLineComplex(cells)
 
 		if table[line.Hash] == nil {
@@ -100,11 +106,11 @@ func (t *TableComplex) parseBuffer(filebuffer []byte) []*LineComplex {
 
 			rows = append(rows, row)
 
-			if t.Min > row.LowSample() {
-				t.Min = row.LowSample()
+			if min > row.LowSample() {
+				min = row.LowSample()
 			}
-			if t.Max < row.HighSample() {
-				t.Max = row.HighSample()
+			if max < row.HighSample() {
+				max = row.HighSample()
 			}
 
 			t.HzLow = row.HzLow
@@ -134,9 +140,17 @@ func (t *TableComplex) parseBuffer(filebuffer []byte) []*LineComplex {
 
 	sort.Sort(LineSort(rows))
 
+	if t.Config.MaxPower == nil {
+		t.Config.MaxPower = &max
+	}
+
+	if t.Config.MinPower == nil {
+		t.Config.MinPower = &min
+	}
+
 	log.WithFields(log.Fields{
-		"pMax": t.Max,
-		"pMin": t.Min,
+		"pMax": *t.Config.MaxPower,
+		"pMin": *t.Config.MinPower,
 	}).Debug("integrated lines")
 
 	t.Integrations = len(rows)
@@ -176,7 +190,6 @@ func (t *TableComplex) IntegrateLines(lines []*LineComplex) *LineComplex {
 		if i > 0 {
 			masterline.AddSamples(l)
 		}
-
 	}
 
 	return masterline
@@ -186,14 +199,21 @@ func (t *TableComplex) ColorAt(x, y int) color.Color {
 
 	cell := t.Rows[y].Sample(x)
 
-	hue_start := 236.0
-	hue_end := 0.0
+	hueStart := 236.0
+	hueEnd := 0.0
 
-	span := (t.Min - t.Max) * -1
-	h_per_deg := (hue_start - hue_end) / span
-	pow_normalized := cell - t.Min
-	pow_degrees := pow_normalized * h_per_deg
-	hue := hue_start - pow_degrees
+	span := (*t.Config.MinPower - *t.Config.MaxPower) * -1
+	hPerDeg := (hueStart - hueEnd) / span
+	powNormalized := cell - *t.Config.MinPower
+	powDegrees := powNormalized * hPerDeg
+	hue := hueStart - powDegrees
+
+	if hue > hueStart {
+		hue = hueStart
+	}
+	if hue < hueEnd {
+		hue = hueEnd
+	}
 
 	return colorful.Hsv(hue, 1, 0.90)