Added GPLv3.0 license

J2ghz/palette

.gitignore

@@ -25,4 +25,3 @@ _testmain.go
 
 /gopow
 /build
-resources.go

LICENSE

@@ -0,0 +1,674 @@
+                     GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
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+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<https://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<https://www.gnu.org/licenses/why-not-lgpl.html>.

Makefile

@@ -1,45 +1,63 @@
 
-.PHONY: setup build resources lint clean
-
 VERSION = $(shell git describe --always --dirty)
 TIMESTAMP = $(shell git show -s --format=%ct)
 
-default: build_darwin
+default: build
 
+.PHONY: setup
 setup: 
 	go get -u github.com/jteeuwen/go-bindata/...
 
+.PHONY: resources
 resources:
 	go-bindata -pkg resources -o internal/resources/resources.go resources/...
 
-build_darwin: resources
-	GOOS=darwin GOARCH=amd64 go build -a -o ./build/gopow *.go
-	zip ./build/gopow_darwin64.zip ./build/gopow
+.PHONY: build
+build:
+	go build -o ./build/gopow *.go
 
-build_linux: resources
-	GOOS=linux GOARCH=amd64 go build -a -o ./build/gopow *.go
-	zip ./build/gopow_linux64.zip ./build/gopow
-
-build_arm5: resources
-	GOOS=linux GOARM=5 GOARCH=arm go build -a -o ./build/gopow *.go
-	zip ./build/gopow_linux_arm5.zip ./build/gopow
-
-build_arm7: resources
-	GOOS=linux GOARM=7 GOARCH=arm go build -a -o ./build/gopow *.go
-	zip ./build/gopow_linux_arm7.zip ./build/gopow
-
-build_win: resources
-	GOOS=windows GOARCH=amd64 go build -a -o ./build/gopow.exe *.go
-	zip ./build/gopow_win64.zip ./build/gopow.exe
-
-all: build_darwin build_linux build_arm5 build_arm7 build_win
+.PHONY: all
+all: build_darwin_x86 build_darwin_arm64 build_linux build_arm5 build_arm7 build_win64 build_win32
 	rm ./build/gopow
 	rm ./build/gopow.exe
 
-lint:
-	golint .
+.PHONY: build_darwin_x86
+build_darwin_x86:
+	GOOS=darwin GOARCH=amd64 go build -a -o ./build/gopow *.go
+	zip ./build/gopow_darwin_amd64.zip ./build/gopow
 
+.PHONY: build_darwin_arm64
+build_darwin_arm64:
+	GOOS=darwin GOARCH=arm64 go build -a -o ./build/gopow *.go
+	zip ./build/gopow_darwin_arm64.zip ./build/gopow
+
+.PHONY: build_linux
+build_linux:
+	GOOS=linux GOARCH=amd64 go build -a -o ./build/gopow *.go
+	zip ./build/gopow_linux_amd64.zip ./build/gopow
+
+.PHONY: build_arm5
+build_arm5:
+	GOOS=linux GOARM=5 GOARCH=arm go build -a -o ./build/gopow *.go
+	zip ./build/gopow_linux_arm5.zip ./build/gopow
+
+.PHONY: build_arm7
+build_arm7:
+	GOOS=linux GOARM=7 GOARCH=arm go build -a -o ./build/gopow *.go
+	zip ./build/gopow_linux_arm7.zip ./build/gopow
+
+.PHONY: build_win64
+build_win64:
+	GOOS=windows GOARCH=amd64 go build -a -o ./build/gopow.exe *.go
+	zip ./build/gopow_win64.zip ./build/gopow.exe
+
+.PHONY: build_win32
+build_win32:
+	GOOS=windows GOARCH=386 go build -a -o ./build/gopow.exe *.go
+	zip ./build/gopow_win32.zip ./build/gopow.exe
+
+.PHONY: clean
 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:
@@ -25,4 +52,7 @@ GLOBAL OPTIONS:
    --help, -h       show help
    --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).

go.mod

@@ -0,0 +1,18 @@
+module github.com/dhogborg/rtl-gopow
+
+require (
+	github.com/codegangsta/cli v1.4.2-0.20150128051617-e1712f381785
+	github.com/dustin/go-humanize v0.0.0-20151125214831-8929fe90cee4
+	github.com/golang/freetype v0.0.0-20160410050536-c67e4d98d212
+	github.com/lucasb-eyer/go-colorful v0.0.0-20150907065137-e524a63fc3d3
+	github.com/sirupsen/logrus v1.6.0
+	golang.org/x/image v0.0.0-20160423080830-f551d3a6b7fc
+)
+
+require (
+	github.com/konsorten/go-windows-terminal-sequences v1.0.3 // indirect
+	github.com/stretchr/testify v1.6.1 // indirect
+	golang.org/x/sys v0.3.0 // indirect
+)
+
+go 1.19

go.sum

@@ -0,0 +1,30 @@
+github.com/codegangsta/cli v1.4.2-0.20150128051617-e1712f381785 h1:dd7vSznOk2xIT8gJyFqbcrshRrTIWtPG7f41LLfTtMY=
+github.com/codegangsta/cli v1.4.2-0.20150128051617-e1712f381785/go.mod h1:/qJNoX69yVSKu5o4jLyXAENLRyk1uhi7zkbQ3slBdOA=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dustin/go-humanize v0.0.0-20151125214831-8929fe90cee4 h1:WX/DKY159S5AHCpmUWGsVKoCXqLSpKd0R1150CWscw8=
+github.com/dustin/go-humanize v0.0.0-20151125214831-8929fe90cee4/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
+github.com/golang/freetype v0.0.0-20160410050536-c67e4d98d212 h1:erqso4t6p/N1EjjNntiZUXlhmdTEIDSmM8lzICeaY/c=
+github.com/golang/freetype v0.0.0-20160410050536-c67e4d98d212/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
+github.com/konsorten/go-windows-terminal-sequences v1.0.3 h1:CE8S1cTafDpPvMhIxNJKvHsGVBgn1xWYf1NbHQhywc8=
+github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/lucasb-eyer/go-colorful v0.0.0-20150907065137-e524a63fc3d3 h1:HKvdgi34B5ivKjlR94L4WMyiC37Kzvmti867/EdbGRk=
+github.com/lucasb-eyer/go-colorful v0.0.0-20150907065137-e524a63fc3d3/go.mod h1:NXg0ArsFk0Y01623LgUqoqcouGDB+PwCCQlrwrG6xJ4=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sirupsen/logrus v1.6.0 h1:UBcNElsrwanuuMsnGSlYmtmgbb23qDR5dG+6X6Oo89I=
+github.com/sirupsen/logrus v1.6.0/go.mod h1:7uNnSEd1DgxDLC74fIahvMZmmYsHGZGEOFrfsX/uA88=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
+github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+golang.org/x/image v0.0.0-20160423080830-f551d3a6b7fc h1:2xx8haaLdeT9SyZMv+NzYjaPJbm5ZU4CzTiF9icqXQg=
+golang.org/x/image v0.0.0-20160423080830-f551d3a6b7fc/go.mod h1:ux5Hcp/YLpHSI86hEcLt0YII63i6oz57MZXIpbrjZUs=
+golang.org/x/sys v0.0.0-20190422165155-953cdadca894 h1:Cz4ceDQGXuKRnVBDTS23GTn/pU5OE2C0WrNTOYK1Uuc=
+golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.3.0 h1:w8ZOecv6NaNa/zC8944JTU3vz4u6Lagfk4RPQxv92NQ=
+golang.org/x/sys v0.3.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

gopow.go

@@ -3,24 +3,22 @@ package main
 import (
 	"os"
 
-	log "github.com/Sirupsen/logrus"
 	"github.com/codegangsta/cli"
+	log "github.com/sirupsen/logrus"
 
 	"github.com/dhogborg/rtl-gopow/internal/gopow"
 )
 
 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 = "0.0.4"
 	app.Author = "github.com/dhogborg"
 	app.Email = "d@hogborg.se"
 
 	app.Action = func(c *cli.Context) {
-
-		if c.Bool("verbose") == true {
+		if c.Bool("verbose") {
 			log.SetLevel(log.DebugLevel)
 		} else {
 			log.SetLevel(log.InfoLevel)
@@ -49,7 +47,6 @@ func main() {
 			}).Fatal("write failed")
 			return
 		}
-
 	}
 
 	app.Flags = []cli.Flag{
@@ -68,6 +65,16 @@ 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",
@@ -76,6 +83,11 @@ func main() {
 			Name:  "no-annotations",
 			Usage: "Disabled annotations such as time and frequency scales",
 		},
+		cli.StringFlag{
+			Name:  "palette",
+			Usage: "Select the palette for output image. [spectrum,yellow]",
+			Value: "spectrum",
+		},
 	}
 
 	app.Run(os.Args)

internal/gopow/annotater.go

@@ -6,9 +6,10 @@ import (
 	"math"
 	"time"
 
-	"code.google.com/p/freetype-go/freetype"
-	log "github.com/Sirupsen/logrus"
 	"github.com/dustin/go-humanize"
+	"github.com/golang/freetype"
+	log "github.com/sirupsen/logrus"
+	"golang.org/x/image/font"
 
 	"github.com/dhogborg/rtl-gopow/internal/resources"
 )
@@ -53,7 +54,7 @@ func (a *Annotator) init() error {
 		return err
 	}
 
-	font, err := freetype.ParseFont(fontBytes)
+	luxisr, err := freetype.ParseFont(fontBytes)
 	if err != nil {
 		return err
 	}
@@ -63,7 +64,7 @@ func (a *Annotator) init() error {
 
 	a.context = freetype.NewContext()
 	a.context.SetDPI(dpi)
-	a.context.SetFont(font)
+	a.context.SetFont(luxisr)
 	a.context.SetFontSize(size)
 
 	a.context.SetClip(a.image.Bounds())
@@ -72,9 +73,9 @@ func (a *Annotator) init() error {
 
 	switch hinting {
 	default:
-		a.context.SetHinting(freetype.NoHinting)
+		a.context.SetHinting(font.HintingNone)
 	case "full":
-		a.context.SetHinting(freetype.FullHinting)
+		a.context.SetHinting(font.HintingFull)
 	}
 
 	return nil
@@ -203,7 +204,7 @@ func (a *Annotator) DrawInfoBox() error {
 	pt := freetype.Pt(left, top)
 	for _, s := range strings {
 		_, _ = a.context.DrawString(s, pt)
-		pt.Y += a.context.PointToFix32(size * spacing)
+		pt.Y += a.context.PointToFixed(size * spacing)
 	}
 
 	return nil

internal/gopow/gopow.go

@@ -8,9 +8,13 @@ import (
 	"os"
 	"time"
 
-	log "github.com/Sirupsen/logrus"
 	"github.com/codegangsta/cli"
 	"github.com/dustin/go-humanize"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	PowerConfigAuto = -9813
 )
 
 type RunConfig struct {
@@ -18,6 +22,9 @@ type RunConfig struct {
 	OutputFile  string
 	Format      string
 	Annotations bool
+	MaxPower    float64
+	MinPower    float64
+	Palette     string
 }
 
 type GoPow struct {
@@ -27,12 +34,21 @@ type GoPow struct {
 }
 
 func NewGoPow(c *cli.Context) (*GoPow, error) {
-
 	config := &RunConfig{
 		InputFile:   c.String("input"),
 		OutputFile:  c.String("output"),
 		Format:      c.String("format"),
 		Annotations: !c.Bool("no-annotations"),
+		MaxPower:    c.Float64("max-power"),
+		MinPower:    c.Float64("min-power"),
+		Palette:     c.String("palette"),
+	}
+
+	if !c.IsSet("max-power") {
+		config.MaxPower = PowerConfigAuto
+	}
+	if !c.IsSet("min-power") {
+		config.MinPower = PowerConfigAuto
 	}
 
 	if config.InputFile == "" {
@@ -65,11 +81,28 @@ 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
+	}
+
+	var palette Palette
+	switch g.config.Palette {
+	case "yellow":
+		palette = &YellowPalette{}
+	default:
+		palette = &SpectrumPalette{}
+	}
 
 	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
 	}
@@ -77,13 +110,12 @@ func (g *GoPow) Render() error {
 	g.image = table.Image()
 
 	for y, row := range table.Rows {
-		for x, _ := range row.Samples {
-			g.image.Set(x, y, table.ColorAt(x, y))
+		for x := range row.Samples {
+			g.image.Set(x, y, palette.ColorAt(table, x, y))
 		}
 	}
 
 	if g.config.Annotations {
-
 		annotator, err := NewAnnotator(g.image, table)
 		if err != nil {
 			return err
@@ -99,7 +131,6 @@ func (g *GoPow) Render() error {
 }
 
 func (g *GoPow) Write() error {
-
 	log.WithFields(log.Fields{
 		"file": g.config.OutputFile,
 	}).Debug("staring output write")

internal/gopow/line.go

@@ -1,11 +1,12 @@
 package gopow
 
 import (
+	"math"
 	"strconv"
 	"strings"
 	"time"
 
-	log "github.com/Sirupsen/logrus"
+	log "github.com/sirupsen/logrus"
 )
 
 type LineComplex struct {
@@ -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/palette.go

@@ -0,0 +1,61 @@
+package gopow
+
+import (
+	"image/color"
+
+	"github.com/lucasb-eyer/go-colorful"
+)
+
+type Palette interface {
+	ColorAt(table *TableComplex, x, y int) color.Color
+}
+
+type YellowPalette struct {
+}
+
+func (p *YellowPalette) ColorAt(table *TableComplex, x, y int) color.Color {
+	cell := table.Rows[y].Sample(x)
+
+	hueStart := 0.0
+	hueEnd := 1.0
+
+	span := (*table.Config.MinPower - *table.Config.MaxPower) * -1
+	hPerDeg := (hueStart - hueEnd) / span
+	powNormalized := cell - *table.Config.MinPower
+	powDegrees := powNormalized * hPerDeg
+	hue := hueStart - powDegrees
+
+	if hue < hueStart {
+		hue = hueStart
+	}
+	if hue > hueEnd {
+		hue = hueEnd
+	}
+
+	return colorful.Color{hue, hue, 0}
+}
+
+type SpectrumPalette struct {
+}
+
+func (p *SpectrumPalette) ColorAt(table *TableComplex, x, y int) color.Color {
+	cell := table.Rows[y].Sample(x)
+
+	hueStart := 236.0
+	hueEnd := 0.0
+
+	span := (*table.Config.MinPower - *table.Config.MaxPower) * -1
+	hPerDeg := (hueStart - hueEnd) / span
+	powNormalized := cell - *table.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)
+}

internal/gopow/table.go

@@ -1,27 +1,24 @@
 package gopow
 
 import (
+	"bytes"
 	"image"
-	"image/color"
 	"io/ioutil"
 	"math"
 	"sort"
 	"strings"
 	"time"
 
-	log "github.com/Sirupsen/logrus"
 	"github.com/dustin/go-humanize"
-	"github.com/lucasb-eyer/go-colorful"
+	log "github.com/sirupsen/logrus"
 )
 
 type TableComplex struct {
-	File string // our input file
+	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 +29,18 @@ 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 {
@@ -47,7 +51,6 @@ func NewTable(file string) (*TableComplex, error) {
 }
 
 func (t *TableComplex) Load(file string) error {
-
 	log.Debug("loading table")
 
 	t.File = file
@@ -68,18 +71,15 @@ func (t *TableComplex) Load(file string) error {
 }
 
 func (t *TableComplex) parseBuffer(filebuffer []byte) []*LineComplex {
+	var max = float64(math.MaxFloat64 * -1)
+	var min = float64(math.MaxFloat64)
 
-	t.Max = float64(math.MaxFloat64 * -1)
-	t.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 {
@@ -93,25 +93,21 @@ func (t *TableComplex) parseBuffer(filebuffer []byte) []*LineComplex {
 
 	// loop over hash keys with lines
 	for _, lines := range table {
-
 		row := t.IntegrateLines(lines)
-
 		if row != nil {
-
 			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
 			t.HzHigh = row.HzHigh
 
 			if row.Time != nil {
-
 				if t.TimeStart == nil {
 					t.TimeStart = row.Time
 				}
@@ -128,15 +124,22 @@ func (t *TableComplex) parseBuffer(filebuffer []byte) []*LineComplex {
 					t.TimeEnd = row.Time
 				}
 			}
-
 		}
 	}
 
 	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)
@@ -156,7 +159,6 @@ func (t *TableComplex) parseBuffer(filebuffer []byte) []*LineComplex {
 }
 
 func (t *TableComplex) Image() *image.RGBA {
-
 	log.WithFields(log.Fields{
 		"width":  t.Bins,
 		"height": t.Integrations,
@@ -166,7 +168,6 @@ func (t *TableComplex) Image() *image.RGBA {
 }
 
 func (t *TableComplex) IntegrateLines(lines []*LineComplex) *LineComplex {
-
 	if len(lines) == 0 {
 		return nil
 	}
@@ -176,25 +177,7 @@ func (t *TableComplex) IntegrateLines(lines []*LineComplex) *LineComplex {
 		if i > 0 {
 			masterline.AddSamples(l)
 		}
-
 	}
 
 	return masterline
 }
-
-func (t *TableComplex) ColorAt(x, y int) color.Color {
-
-	cell := t.Rows[y].Sample(x)
-
-	hue_start := 236.0
-	hue_end := 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
-
-	return colorful.Hsv(hue, 1, 0.90)
-
-}