Readonly axisXReadonly axisYReadonly chartReadonly scaleScale of the series
Add callback function to be triggered when specified event is fired.
// Example syntax
object.addEventListener('click', (event) => {
console.log(event)
})
Some classes also report extra information about the interacted object with the second parameter:
// Most series share information about interacted data point
series.addEventListener('click', (event, info) => {
console.log(info)
})
Optional third parameter allows registering event handlers that will automatically remove themselves after first trigger:
// Example this listener will only fire once
object.addEventListener('click', (event) => {})
Each class has its own list of supported events.
Some events are from HTML standard (click, pointerdown, etc.),
while others are own events from LightningChart JS (dispose, resize, etc.)
To find what events are available, you can try following:
TypeScript enabled, just write addEventListener and see what possible event types the IDE suggests. These APIs are strongly typed, and even the callback event will be correctly typed.K type parameter extends.Callback function that is triggered when event is fired.
Optional options: LCJSAddEventListenerOptionsOptional extra configuration options.
Push a Matrix of intensity values into the Heatmap grid. Each value describes one cell in the grid.
Order of data is selected when creating the series;
scrollDimension: 'columns' ->
[
[
0, // Intensity value column = 0, row = 0
0, // Intensity value column = 0, row = 1
0, // Intensity value column = 0, row = n
],
[
0, // Intensity value column = 1, row = 0
0, // Intensity value column = 1, row = 1
0, // Intensity value column = 1, row = n
],
]
scrollDimension: 'rows' ->
[
[
0, // Intensity value row = 0, column = 0
0, // Intensity value row = 0, column = 1
0, // Intensity value row = 0, column = n
],
[
0, // Intensity value row = 1, column = 0
0, // Intensity value row = 1, column = 1
0, // Intensity value row = 1, column = n
],
]
Example usage:
// Create x-scrolling intensity heatmap.
const series = ChartXY.addHeatmapScrollingGridSeries({
heatmapDataType: 'intensity',
scrollDimension: 'columns',
resolution: 5,
})
// Push a column into heatmap.
series.addIntensityValues([
[0, 10, 0, 20, 0]
])
invalidateIntensityValues can trigger warnings when used controversially.
In production applications, these can be controlled with warnings.
Object itself for fluent interface.
Matrix of intensity values - Each array represents a column or row, and each number represents a cell in the grid.
Attach object to an legendBox entry
Series itself for fluent interface
Object which has to be attached
Flag that indicates whether the Attachable should be hidden or not, when its respective Entry is clicked.
By default, entries are assigned a smooth looking gradient based on the component color. If this flag is true, then this is skipped, and exact component solid fill is used instead.
Clear all previous data pushed to the series.
Object itself for fluent interface.
Permanently destroy the component.
To fully allow Garbage-Collection to free the resources used by the component, make sure to remove any references to the component and its children in application code.
let chart = ...ChartXY()
let axisX = chart.getDefaultAxisX()
// Dispose Chart, and remove all references so that they can be garbage-collected.
chart.dispose()
chart = undefined
axisX = undefined
Object itself for fluent interface
Get whether series is taken into account with automatic scrolling and fitting of attached axes.
By default, this is true for all series.
true default, axes will take series into account in scrolling and fitting operations.
false, axes will ignore series boundaries.
Read whether series rendering should be clipped to the area enclosed by its owning axes or not. All series rendering is ALWAYS clipped so that it doesn't leak outside the owning charts series area. However, it is optional whether the series rendering should be able to leak outside the series owning axes viewport, which might be smaller than the charts viewport (for example, when using stacked axes).
By default, clipping is enabled (true).
True or false.
Beta
Get override behavior for when this series is formatted to be displayed by a cursor.
Override callback or undefined
Introduced in v6.0.0, the state and definition of this API is not finalized. It may change in future versions without regard to backwards compatibility if there is significant cause from user feedback.
Get theme effect enabled on component or disabled.
A theme can specify an Effect to add extra visual oomph to chart applications, like Glow effects around data or other components.
Whether this effect is drawn above a particular component can be configured using the setEffect method.
// Example, disable theme effect from a particular component.
Component.setEffect(false)
For the most part, theme effects are enabled by default on most components.
Theme effect is configured with effect property.
Boolean that describes whether drawing the theme effect is enabled around the component or not.
Get heatmap fill pixel interpolation mode.
Heatmap fill pixel interpolation mode selection.
Get boolean flag that is true when a Pointer device is over the chart component.
In order for this method to work, the components pointer event tracking must be enabled (getPointerEvents)
Boolean
Invalidate existing and/or add new intensity values in the Heatmap grid. The location along scrolling dimension is identified by a sample index.
Sample index 0 would reference the first sample in the heatmap, whereas 1 the second sample.
This allows, for example, the modification of previously pushed heatmap samples.
This method is also capable of adding new samples into the heatmap, which happens if the sample index exceeds the currently existing sample count (this can be received with getSampleCount method).
If this method is used to push new samples into the heatmap in a manner where gaps form between the new samples and previous ones, the gaps are automatically filled by duplicating the previous last heatmap sample!
// Example, modify last sample pushed to heatmap
heatmapSeries.invalidateIntensityValues({
iSample: heatmapSeries.getSampleCount() - 1,
values: [[0, 0, 0, 0, 0]]
})
// Example, update 5 samples starting at sample index 2
heatmapSeries.invalidateIntensityValues({
iSample: 2,
values: [
[0, 0, 0],
[0, 0, 0],
[0, 0, 0],
[0, 0, 0],
[0, 0, 0],
]
})
Object itself.
Object with sample index and intensity values parameters.
Remove event listener added using addEventListener.
The expected argument should be the exact same callback function that was supplied using addEventListener:
// Basic example syntax
const listener = () => {}
obj.addEventListener('click', listener)
obj.removeEventListener('click', listener)
// Basic boilerplate of custom interaction when user drags on an object
obj.addEventListener('pointerdown', (eventDown) => {
let prevCoord = eventDown
const handlePointerMove: LCJSInteractionEventListener<'pointermove'> = (eventMove) => {
const delta = { x: eventMove.clientX - prevCoord.clientX, y: eventMove.clientY - prevCoord.clientY }
prevCoord = eventMove
console.log(delta, eventMove.clientX, eventMove.clientY)
}
const handlePointerUp: LCJSInteractionEventListener<'pointerup'> = (eventUp) => {
window.removeEventListener('pointermove', handlePointerMove)
window.removeEventListener('pointerup', handlePointerUp)
}
window.addEventListener('pointermove', handlePointerMove)
window.addEventListener('pointerup', handlePointerUp)
})
Listener that was added using addEventListener.
Set component highlight animations enabled or not. For most components this is enabled by default.
// Example usage, disable highlight animations.
component.setAnimationHighlight(false)
Object itself
Animation enabled?
Set whether series is taken into account with automatic scrolling and fitting of attached axes.
By default, this is true for all series.
By setting this to false, any series can be removed from axis scrolling/fitting.
// Example syntax, remove series from automatic scrolling / fitting.
LineSeries.setAutoScrollingEnabled(false)
Object itself for fluent interface.
true default, axes will take series into account in scrolling and fitting operations.
false, axes will ignore series boundaries.
Configure whether series rendering should be clipped to the area enclosed by its owning axes or not. All series rendering is ALWAYS clipped so that it doesn't leak outside the owning charts series area. However, it is optional whether the series rendering should be able to leak outside the series owning axes viewport, which might be smaller than the charts viewport (for example, when using stacked axes).
By default, clipping is enabled (true).
// Example, disable clipping, allowing the series rendering to leak outside its own axes.
SeriesXY.setClipping(false)
Object itself
Clipping enabled or disabled.
Configure whether cursors should pick on this particular series or not.
// Example, prevent chart auto cursor from snapping to a series.
LineSeries.setCursorEnabled(false)
Related API:
Beta
Set override behavior for when this series is formatted to be displayed by a cursor. This can be used to alter and expand on cursor formatting done for a specific series, either by the library's default cursor formatters or even the users own cursor formatters defined on chart level.
// Example syntax, add extra row to display a custom data property
series.setCursorFormattingOverride((hit, before) => {
if (!isHitSampleXY(hit)) return before
const customPropertyValue = data[hit.iSample].customProperty
return [...before, ['ASD', '', customPropertyValue.toFixed(3)]]
})
To use this with users own cursor formatters, you can use useCursorFormatterSeriesOverride:
// Example syntax, define custom cursor formatting with support for series overrides
chart.setCursorFormatting((_, __, hits) => {
return [
[hits[0].axisX.formatValue(hits[0].x)],
...hits.map((hit) => useCursorFormatterSeriesOverride(hit, [['Y:', '', hit.axisY.formatValue(hit.y)]])).flat(),
]
})
Object itself.
Introduced in v6.0.0, the state and definition of this API is not finalized. It may change in future versions without regard to backwards compatibility if there is significant cause from user feedback.
Override callback or undefined
Disable automatic data cleaning.
// Example syntax, disable data cleaning.
series.setDataCleaning(undefined)
Object itself for fluent interface.
Data cleaning configuration.
Enable automatic data cleaning by minDataPointCount configuration.
Specifying minDataPointCount enables lazy cleaning of data that is outside view as long as the remaining data amount doesn't go below the configured threshold.
// Example syntax for specifying minDataPointCount
series.setDataCleaning({ minDataPointCount: 10000 })
Usage of minDataPointCount is recommended in most common applications that require automatic data cleaning.
The actual value is often not very particular, just setting it above 0 to enable it is usually enough (lazy data cleaning of out of view data).
// Example, enable lazy data cleaning of out of view data.
series.setDataCleaning({ minDataPointCount: 1 })
Object itself for fluent interface.
Data cleaning configuration.
Enable automatic data cleaning by maxDataPointCount configuration.
Specifying maxDataPointCount results in data cleaning always happening exactly when total data amount exceeds the supplied threshold.
// Example syntax for specifying maxDataPointCount
series.setDataCleaning({ maxDataPointCount: 10000 })
maxDataPointCount is usually used in memory limited applications to prevent running out of memory.
maxDataPointCount is currently only supported by only select series:
If the feature receives good support and usage from the user base, it might be expanded to all series types in a future release.
Object itself for fluent interface.
Data cleaning configuration.
Configure draw order of the series.
The drawing order of series inside same chart can be configured by configuring their seriesDrawOrderIndex.
This is a simple number that indicates which series is drawn first, and which last.
The values can be any JS number, even a decimal. Higher number results in series being drawn closer to the top.
By default, each series is assigned a running counter starting from 0 and increasing by 1 for each series.
// Example, create 2 series and configure them to be drawn in reverse order.
const series1 = ChartXY.addLineSeries()
.setDrawOrder({ seriesDrawOrderIndex: 1 })
const series2 = ChartXY.addLineSeries()
.setDrawOrder({ seriesDrawOrderIndex: 0 })
// Example, ensure a series is drawn above other series.
SeriesXY.setDrawOrder({ seriesDrawOrderIndex: 1000 })
Object itself.
Object with seriesDrawOrderIndex property.
Set theme effect enabled on component or disabled.
A theme can specify an Effect to add extra visual oomph to chart applications, like Glow effects around data or other components.
Whether this effect is drawn above a particular component can be configured using the setEffect method.
// Example, disable theme effect from a particular component.
Component.setEffect(false)
For the most part, theme effects are enabled by default on most components.
Theme effect is configured with effect property.
Object itself.
Theme effect enabled
Set fill style of heatmap series.
Supported fill styles:
PalettedFill:
Colors heatmap fill by looking color up from LUT based on heatmap intensity values.
// Example, color look up by intensity values.
heatmapSeries.setFillStyle(
new PalettedFill({
lut: new LUT({
steps: [
{ value: 0, color: ColorCSS('red') },
{ value: 20, color: ColorCSS('blue') },
],
interpolate: true,
}),
}),
)
Intensity values are defined when data is pushed in with addIntensityValues method.
Note, Heatmap doesn't currently support color (fallback color).
SolidFill:Solid color for all heatmap cells. Supported for debugging purposes mainly.
emptyFill:
Disables heatmap fill.
// Example, hide heatmap fill and show wireframe.
heatmapSeries
.setFillStyle(emptyFill)
.setWireframeStyle(new SolidFill({ color: ColorRGBA(255, 0, 0) }))
Object itself for fluent interface.
FillStyle object or function which modifies current value.
Set state of component highlighting.
// Example usage
component.setHighlight(true)
component.setHighlight(0.5)
If highlight animations are enabled (which is true by default), the transition will be animated. As long as the component is highlighted, the active highlight intensity will be animated continuously between 0 and the configured value. Highlight animations can be disabled with setAnimationHighlight
Object itself
Boolean or number between 0 and 1, where 1 is fully highlighted.
Set highlight on mouse hover enabled or disabled.
Mouse interactions have to be enabled on the component for this to function as expected. See setPointerEvents for more information.
Object itself for fluent interface.
True if highlighting on mouse hover, false if no highlight on mouse hover
Beta
Set icon of the chart component. This is displayed in legends and by default cursor formatters.
const image = new Image()
image.src = 'image.png'
const icon = chart.engine.addCustomIcon(image)
ChartComponent.setIcon(icon)
Object itself.
Released as beta feature in v5.2.0 feature may still change according to user feedback and experiences.
Icon
Sets the name of the Component updating attached LegendBox entries
Object itself
Name of the Component
Set heatmap fill pixel interpolation mode.
'disabled' or undefined: Interpolation disabled; all pixels within a grid cell share the same color.
'bilinear': Each pixel is colored individually by bilinear interpolation.
Object itself for fluent interface.
Heatmap fill pixel interpolation mode selection.
Set whether element can be target of pointer events or not.
Disabling pointer events means that the objects below this component can be interacted through it.
Object itself for fluent interface
Specifies state of mouse interactions
Set start coordinate of Heatmap on its X and Y axis.
Object itself.
Coordinate on axis where 1st heatmap sample will be positioned.
Set Step between each consecutive heatmap value on the X and Y Axes.
X = columns, Y = rows
Object itself.
Axis offset between heatmap samples.
Set element visibility.
Object itself.
true when element should be visible and false when element should be hidden.
Set style of wireframe.
Wireframe is a line grid that highlights the edges of each cell of the heatmap.
// Example, disable wireframe.
heatmapSeries.setWireframeStyle(emptyLine)
// Example, set wireframe style.
heatmapSeries.setWireframeStyle(new SolidLine({
thickness: 1,
fillStyle: new SolidFill({ color: ColorRGBA(255, 0, 0, 255) })
}))
Note that wireframe is not supported on high precision axis!
Series itself for fluent interface.
Either a LineStyle object or a function, which will be used to create a new LineStyle based on current value.
Method for solving the nearest data point to a given coordinate on screen.
// Example syntax
chart.onSeriesBackgroundMouseClick((_, event) => {
const nearest = series.solveNearest(event, 'show-nearest')
console.log(nearest)
})
SolveResult object or undefined.
Reference coordinate on web page as client coordinates. This can for example be directly an Event object.
Optional control for solve nearest behavior
Match legend entry style to reflect components own style.
By default, entries are assigned a smooth looking gradient based on the component color. If this flag is true, then this is skipped, and exact component solid fill is used instead.
Series class for visualizing a Heatmap Grid, with API for pushing data in a scrolling manner (append new data on top of existing data).
HeatmapScrollingGridSeriesIntensityValuesis optimized for massive amounts of data - here are some reference specs on average PC to give an idea:rows: 2048, 1000 columns/s) runs consistently and smoothly with 60 FPS and no stuttering. CPU usage stays easily below 40%.rows: 4096, 2000 columns/s) runs consistently and smoothly with 60 FPS and minor stuttering.HeatmapScrollingGridSeriesIntensityValuesmax data amount is entirely restricted by the client hardware RAM and more specifically amount of RAM usable by the context running LightningChart JS. If performance suddenly plummets at some approximate data threshold, then it is likely that there is not enough RAM available. Use data cleaning configuration and suitable Axis intervals to adjust to your hardware limitations.Each cell of the heatmap grid is associated with a numeric intensity value, which can be used in conjuction with a Color look up table (LUT).
Created with addHeatmapScrollingGridSeries.
Frequently used API: