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plot-grid

2.4.2 • Public • Published

plot-grid unstable gzip-size

Grid component for webgl/canvas2d with zooming, panning, polar mode etc. See demo.

Usage

npm install plot-grid

const createGrid = require('plot-grid');
 
//cartesian grid
let grid = createGrid({
    x: {
        type: 'logarithmic',
        min: 0
    },
    y: {
        min: -100,
        max: 0
    }
});

This will create frequency response and directional diagram.

API

let grid = new Grid(options?)

Create new grid instance. It can serve both as a class or constructor function (no new). By default it displays cartesian grid, but

Name Default Description
container document.body Container to place grid into. Can be null to render in memory.
context null Can be pre-existing context.
pixelRatio window.devicePixelRatio Pixel ratio of canvas.
autostart true Render every frame automatically or call render method manually. Useful if plot-grid is used in cooperation with other components.
interactions true Enable pan/zoom interactions, see interact event.
x, y, r, a Bool, String, Object Boolean, enabling coordinates of linear type or a string, defining custom type: linear, logarithmic or time. If object is passed, it defines custom lines behaviour, see the table below.

Each of x, y, r, a can be customized by the following options:

Name Type Default Description
type String, null null Default type to extend, one of linear, logarithmic, time.
color String rgba(0,0,0,1) Default color for the lines, axes, ticks and labels.
format Function null Formatter for label values. Takes a value and returns a string. pretty-number can be used as such.
lines Bool, Array, Function, null Array with values, defining lines, or function returning such array, state => [values...]. Can be disabled by passing false. By default implemented by type.
ticks Bool, Array, Number, Function 5 Tick size. Can be disabled by passing false.
labels Bool, Array, Object , Function, null null Object or array with labels corresponding to lines. Can be defined as a function returning such array (state) => labels. null value will output values as is. Can be disabled by passing false.
axis Bool true Enable axis.

Pan & zoom

Additional pan/zoom params can be set for each coordinate x, y, r, a:

Name Type Default Description
offset Number 0 Defines start point for the visible range, in terms of values.
origin Number 0.5 Defines position of the offset on the screen, for example, .5 for center, 1 for right/top edge of the screen, 0 for left/bottom.
scale Number 1 Sets scale for the current range, number of values per pixel.
min, max Number -Infinity, Infinity Limits for panning.
minScale, maxScale Number 0, Infinity Scale limits.
zoom Bool true Enables zoom interaction.
pan Bool true Enables pan interaction.

To change pan or zoom, use update method with the propertives above, as update({x: {offset, scale}, y: {offset, scale});.

Another time it might be useful to engage grid.on('interact', grid => {}) handler for grid interactions, like moving and zooming.

Style

Each coordinate can be customized more with additional options:

Name Type Default Description
lineColor String, Number, Function, null .3 Color for lines. Number value will take the base color above with changed opacity. Function signature is state => [...values].
lineWidth Number 1 Width of lines. We guess that width of sublines should not differ from the width of lines, if you have use-case requiring the opposite, please address issues.
axisOrigin Number 0 Define axis alignment by value on the opposite coordinate.
axisColor String, Number 0.1 Axis color, redefines default color.
axisWidth Number 2 Width of axis line.
align Number 0.5 The side to align ticks and labels, 0..1.
fontSize String, Number 10pt Font size for labels. Sizes with units will be automatically transformed to pixels by to-px.
fontFamily String sans-serif Font family to use for labels.
padding WIP Number, Array(4) 0 Padding inside the viewport to indent lines from axes and labels. Ordering is top, right, bottom, left, as in css.
style WIP String lines Style of rendering: lines or dots. Note that dots is available only when x and y are both enabled.
distance Number 120 Minimum distance between lines.

grid.update(options)

Pass new options to update grid look. Note that passed options extend existing ones.

grid.update({
    x: {
        type: 'logarithmic',
        offset: 0,
        min: 0,
        scale: .01
    }
});

Note that you may need to call render in manual mode grid.update().render().

grid.render()

Redraw grid. Call whenever you need to redraw grid, like resize etc. It will not recalculate lines, just rerender existing lines. To recalculate lines, use grid.update().

grid.draw()

Directly invoke draw method, useful in case if grid needs to be drawn over other content.

Used by

Thanks

To @evanw with thetamath for grid API inspiration.

Related

  • grid — collection of grids for canvas2d.

Install

npm i plot-grid

DownloadsWeekly Downloads

7

Version

2.4.2

License

MIT

Last publish

Collaborators

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