README
¶
Go Chart Lib
Dead simple rrd like bandwidth charts with focus on pixel perfect rendering of source data.
Written in Go, the output can either be an interactive SVG chart or a static PNG image.
It was written to be able to show tens or hundreds of charts in seconds without interactivity in mind.
The SVG image allows basic analytics to be performed on the chart, like measurements of time or volume, showing/hiding datasets and showing a weighted moving average on demand.
Source data can be upsampled using a simple stretch method (bar charts) or downsampled using the largest triangle three buckets algorithm.
The javascript embedded in the SVG image does not have any dependencies.
Examples
Example screenshot:
Screenshots from the example website:
Example Usage
Example demo app:
go get github.com/tomarus/chart
go run $GOPATH/src/github.com/tomarus/chart/examples/main.go
open http://localhost:3000
Example /proc monitoring app (linux only):
go get github.com/tomarus/chart
go run $GOPATH/src/github.com/tomarus/chart/examples/sysmon/main.go
open http://localhost:3001
Code example:
import (
"github.com/tomarus/chart"
"github.com/tomarus/chart/svg"
)
opts := &chart.Options{
Title: "Traffic",
Image: svg.New(), // or png.New()
Size: "auto", // big is 1440px, small is 720px, auto is size of dataset
Height: 300, // Defaults to -1, when size=auto height=width/4, otherwise set fixed height
Scheme: "white", // or black/random/pink/solarized or hsl:180,0.5,0.25
Start: start_epoch,
End: end_epoch,
W: w,
SIBase: 1000, // or use 1024 to scale, only used when axes are not specified.
// If you don't specify axes, they will be automatically calculated using some defaults.
Axes: []*axis.Axis{
axis.NewTime(axis.Bottom, "Mon 15:04").Duration(8 * time.Hour).Grid(4),
axis.NewSI(axis.Left, 1000).Ticks(4).Grid(2),
},
}
c, err := chart.NewChart(opts)
if err != nil {
panic(err)
}
err = c.AddData(&data.Options{Title: "My Data Description"}, []yourData)
if err != nil {
panic(err)
}
w.Header().Set("Content-Type", "image/svg+xml")
err = c.Render()
if err != nil {
panic(err)
}
Notes
This is an experimental work in progress for my own personal educational and research purposes.
This project has just started and a lot of stuf is still missing or incomplete. The API will not be stable until 1.0.0 is tagged in git.
This is a small list of ideas, todos and limitations:
- Custom lines and markers, like 95th percentile line, downtime markers, etc
- Add support negative values
- It supports only area charts atm
- Only 4 sources per chart supported currently
Documentation
¶
Overview ¶
Package chart generates interactive svg or png charts from time series data.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Chart ¶
type Chart struct {
// contains filtered or unexported fields
}
Chart is the main chart type used for all operations.
Example ¶
opts := &Options{
Title: "Title on top of the chart",
Image: svg.New(), // or png.New()
Size: "big", // big is 1440px, small is 720px, auto is size of dataset
Height: 300, // Defaults to -1, when size=auto height is set to width/4, otherwise set fixed height
Width: 900, // If a width is supplied, height is implied and both are used in stead of size setting
Scheme: "white", // or black/random/pink/solarized or hsl:180,0.5,0.25
Theme: "light", // default is dark.
Start: time.Now().AddDate(0, 0, -1).Unix(),
End: time.Now().Unix(),
W: os.Stdout,
Axes: []*axis.Axis{
axis.NewTime(axis.Bottom, "01-02 15:04").Duration(4 * time.Hour).Grid(4),
axis.NewSI(axis.Left, 1000).Ticks(4).Grid(2),
//
// - Example custom time format
// axis.New(axis.Bottom, func(in float64) string {
// return time.Unix(int64(in), 0).Format("01-02 15:04")
// return in.(time.Time).Format("2006-01-02")
// }).Duration(4 * time.Hour).Grid(),
//
// - Example other custom format
// axis.New(axis.Left, func(in float64) string {
// return fmt.Sprintf("%.1f", in/3.14)
// }).Ticks(5).Grid(),
},
}
c, err := NewChart(opts)
if err != nil {
panic(err)
}
exdata := make([]float64, 256)
for i := 0; i < 255; i++ {
exdata[i] = float64(i)
}
warn := c.AddData(&data.Options{Type: "area", Title: "My Data Description"}, exdata)
if err != nil {
fmt.Println(warn)
}
c.Render()
type Options ¶
type Options struct {
Title string // guess what, leave empty to hide
Size string // big is 1440px, small is 720px, auto is size of dataset
Width, Height int // overrides Size
Scheme string // palette colorscheme, default "white"
Theme string // if random scheme is used, set to "light" to use light colors, otherwise a dark theme is generated
Start, End int64 // start + end epoch of data
Image image.Image // the chart image type, chart.SVG{} or chart.PNG{}
W io.Writer // output writer to write image to
SIBase int // SI Base for auto axis calculation, default is 1000.
Axes []*axis.Axis
}
Options defines a type used to initialize a Chart using NewChart()
Source Files
Directories
¶
| Path | Synopsis |
|---|---|
|
sysmon
command
Command sysmon is a basic /proc system monitoring tool storing only the last 15 minutes of data, sampled each second, in memory.
|
Command sysmon is a basic /proc system monitoring tool storing only the last 15 minutes of data, sampled each second, in memory. |
|
Package svg provides the svg interface for tomarus chart lib.
|
Package svg provides the svg interface for tomarus chart lib. |