davvo / node-gnuplot

A thin wrapper around gnuplot for node.js

node-gnuplot

A super-thin wrapper around gnuplot for node.js

example

var gnuplot = require('gnuplot');
gnuplot()
    .set('term png')
    .set('output "out.png"')
    .set('title "Some Math Functions"')
    .set('xrange [-10:10]')
    .set('yrange [-2:2]')
    .set('zeroaxis')
    .plot('(x/4)**2, sin(x), 1/x')
    .end();

You can use streams!

var data = fs.createReadStream('input.dat'),
    out = fs.createWriteStream('output.svg'),
    plotter = gnuplot().set('term svg');
    
data.pipe(plotter).pipe(out);

methods

var gnuplot = require('gnuplot')

gnuplot()

Spawn a new gnuplot process and return a duplex stream combining stdout and stdin.

gnuplot.print(data, options={})

Write data to stdin of the gnuplot process. If the stream should be closed after the write, pass {end: true} as options.

gnuplot.println(data, options={})

Same as gnuplot.print(data + '\n', options)

gnuplot.set(data, options={})

Same as gnuplot.println('set ' + data, options)

gnuplot.unset(data, options={})

Same as gnuplot.println('unset ' + data, options)

gnuplot.plot(data, options={})

Same as gnuplot.println('plot ' + data, options)

gnuplot.splot(data, options={})

Same as gnuplot.println('splot ' + data, options)

gnuplot.replot(data='', options={})

Same as gnuplot.println('replot ' + data, options)

All of the above functions returns the gnuplot object and can be chained together:

gnuplot()
    .set('term png')
    .unset('output')
    .plot('[-6:6] sin(x)')
    .end();

To automatically call end() on the input stream after a command, pass {end: true} as options:

gnuplot()
    .set('term png')
    .unset('output')
    .plot('[-6:6] sin(x)', {end: true})
    .pipe(fs.createWriteStream('out.png'));

install

With npm do:

npm install gnuplot

You need to have gnuplot installed. On OSX you can do this with homebrew:

brew install gnuplot

license

ISC

node-gnuplot's Issues

Callback before image generation finish

Hi, I'm using gnuplot in order to create an image and send it in Telegram, the function it's like this:

function img_generation (result, callback) {

  let plot = gnuplot()
    .set('terminal png medium size 400,300')
    .set('output "out.png"')
    .set('title "Isotopic distribution"')
    .unset('key') // no legend
    .set('border 3')
    .set('xlabel "m/z (Da)"')
    .set('ylabel "Intensity (%)"')
    .set('ytics nomirror') // hide ticks left
    .set('xtics nomirror') // hide ticks top
    .set('grid xtics lw 1 lc rgb "#dddddd"')
    .set('grid ytics lw 1 lc rgb "#dddddd"')
    .set('xrange [' + result.chartXFrom + ':' + result.chartXTo + ']')
    .set('yrange [0:120]');

  result.xy.forEach( (point) => {
    plot.set('arrow from ' + point[0] + ',0 to ' + point[0] + ',' + point[1] * 100 + ' nohead lw 2 lc rgb "blue"');
  });
  plot.plot('sin(x) lc rgb "white"');
  plot.end( (err) => {
    if (err) console.error(err);

   // here I send the image
    bot.sendPhoto(fromId, 'out.png');
  });
}

The problem is that the image it's trying to be sended before it's generated, do you have any idea why it's that happening?

Thanks, I love your module 👍

Add 'replot' command

it would be nice to add the replot command :)

Error handling?

Is there any error handling in this? What happens when an instruction (string) given to gnuplot creates and error and fails to produce a plot? I'm not seeing any obvious way to get feedback if something fails. Thanks!

add pause support

if you add 'pause', then running from command line can open x11 windows.

in gnuplot.js
['set', 'unset', 'plot', 'splot', 'replot','pause'].forEach(function (name) {

thanks.

set is not working correctly

direct access to term libraries as an alternative to canvas and cairo

Have you seen a project which uses gnuplot's term library api (is there one) as an alternative to node-canvas and cairo? Say I want to write a new term and want to access it like canvas from vega-scenegraph to write to a PLY or STL 3d printer file? Thanks!