Category: JavaScript

I’m trying to add a axis label/marker to the yAxis of my chart.
This label should follow the intersection between a FastLineRenderableSeries (that i’m using to render a moving average filtered dataSeries) and the yAxis.

I tried to extend the “draw” method of the FastLineRenderableSeries to draw a label ontop of the yAXis, using the “drawModifiersAxisLabel” helper function. Like:

class CustomFastLineRenderableSeries extends FastLineRenderableSeries {
draw(renderContext: WebGlRenderContext2D, renderPassData: RenderPassData) {
    super.draw(renderContext, renderPassData)
    const yAxis = getYAxis(this.parentSurface);
    drawModifiersAxisLabel(
        yAxis,
        renderContext,
        150, // testing values
        "#00ff00", // testing values
        "#00ff00", // testing values
    );
}

but the label don’t get drawn.

The attached image shows the desired feature (image from another charting lib)

How can I implement this?

I have a use case for a chart, that is a heatmap, which may also contain multiple series drawn on top, with multiple internal axis as well.
I can’t transform the data I receive, because that would be too slow, and it needs to maintain a speedy feeling, even when appending more data.

For this reason, when building the chart, I just flip the axis. The bottom axis is the Y axis, and the left axis it the X axis.

The multiple series that can be added (XyDataSeries), provide one extra axis each, and use one of the main axis.
We can think of them as horizontal or vertical series, depending if they use the main X axis, or the main Y axis.

When hovering over the chart, I want to show a tooltip, that shows for each series, their own axis value.

The issue — The normal CursorModifier, can’t correctly present a tooltip, for this case of mixed horizontal/vertical series. I’m not sure if there are configurations I’m missing, or if it is an actual uncovered edge case, hoping to get an answer on this.

To show what the issue is, and how I’m currently fixing it, please have a look at the codepen I made -> https://codepen.io/jrfv/full/zYMjEzP

Any tips on this, is it something scichart will fix eventually?

Hello,

Can you show this example(https://codepen.io/PodaRocheK/pen/yLGxGEL?editors=0011) and tell me, why metadata labels are not displayed in some cases? May be you can tell me how to do it correctly? A have similar chart with a lot of datapoints and can’t understand why labels show only in some time(20s or > 1m after start the chart)

Thank you!

Hi,

I am facing a issue with latest version of SciChart. Because of this type error not able to build the project. Can you check this error.

Hi, I have an issue where I am trying to create multiple xAxes where one is normal and the rest are horizontally stacked. Then I calculate the stacked length of each stacked axes, but the issue comes when I change the width of the chart or inspect element, which would alter the width of the chart somehow, I got error saying the total width of the stacked axes is bigger than available size.

I have a codesanbox example of it:
https://codesandbox.io/s/scichart-stacked-xaxis-stacked-length-issue-3knt23?file=/src/App.tsx

I am using percentage for the stacked xAxes length and then I added them up to be 100% total, but somehow it is saying that it is more than available size.

So, my question is, how can I listen or get the width/size changes event of the chart/xAxis, so that I can calculate accordingly?

Please tell me, is it possible to make sure that there is no empty space between records on those days when there is no trading on the stock exchange? It appears that the X-axis is linear and not transactional. How can I make it transactional?

Hi,

I am creating an application where, we fetch data and display it in multiple heatmaps. The user can manipulate the heatmaps with changing colormap or changing ranges on the colormap.

Data from these multiple heatmaps is composited to another chart for visualization.

I was able to get a reference to the series, but adding the series to another chart errors with a message:

Invalid operation in sciChartSurface.attachSeries, this series has already been attached to a SciChartSurface. Please detach it from a SciChartSurface before attaching to another
at BaseRenderableSeries.onAttach (BaseRenderableSeries.js:634:1)
at __webpack_modules__../node_modules/scichart/Charting/Visuals/SciChartSurface.js.SciChartSurface.attachSeries (SciChartSurface.js:1385:1)

of course this means we cannot attach the same series to two different charts, but is there a way around this such as deepcloning?

renderable series: attached image

sample code: attached image

Dear Andrew,

Thank you for the past answers. I have a new question. I have a heatmap with 2 line charts at its left aand top position. the top line chart plot the horizontal values where the mouse if hovering and left chart displays vertical values from the mouse position.

This is working great, but the issue is the heatmap is not always square and I am trying the aligh the line charts with the heatmap dimensions

two issues,

1. the heatmap X/Y dimension are not always same, in fact I have a function which listens to the changing heatmap zoom factor and makes sure the X/Y are always “square” as we want to show the heatmap with square pixels. (see video #2) https://youtu.be/wXStF-7bWsw

2. As I dynamically chage the size of the plot the… the proportion of actual chart area to axis lable changes thus varying the overlap. (see video #1) https://youtu.be/loAVpYSRJ38

Let me know if you need more information,

Best,

Pramod

Hello, how do I remove the shadow from tooltips, generated by the VerticalSliceModifier?

Thanks!

Hi,

EDataLabelSkipMode Customization is possible with some time range limit?
When i checked the documentation saw the options to skip the label for overlaping. Is it possible can add some index to skip the values. Eg: for Time chart One value is displayed in the chart at 10:30:00. So if i add some index value to skip the next 1 min data. So based on skip index next available value can ba displayed in chart. (10:31:00 or next available value). Can you implement this option to skip ?

I have a chart in the center of the page and the chart will resize according to the browser window size. When I expand the browser window, the chart will expand to fit the browser size. In this case, the chart grows downward gradually (with animation). How can I remove this animation effect when resizing the chart?

In case it’s related to my style. Here are my markup and style for reference:

//Markup

//Style
.contentPanel {
flex: 1 1 auto;
width: calc(100% – 335px);
max-height: calc(100vh – 108px);
display: flex;
flex-direction: column;
}

.chartContainer {
position: relative;
margin: 10px 0;
display: flex;
flex-direction: column;
flex: 1;
}

.scichart-root {
width: 100%;
height: 100%;
}

In a DateTimeNumericAxis, can I convert the number from VisibleRange to a formatted string HH:MM:SS?
For example, I’d like to convert this x1 to 12/1/1984, 3:00:00 PM, or 15:00:00.

let x1 = this.parentSurface.annotations.getById("hrv").x1;
// x1 =470761200, seconds since 1970.01.01 00:00:00

Thanks.

I am considering applying server-side licensing for my javerScript application.

In the document below, there is a phrase “Our server-side licensing component is written in C++.”
(https://support.scichart.com/index.php?/Knowledgebase/Article/View/17256/42/)

However, there is only asp.net sample code on the provided github.
(https://github.com/ABTSoftware/SciChart.JS.Examples/tree/master/Sandbox/demo-dotnet-server-licensing)

I wonder if there is a sample code implemented in C++ for server-side licensing.

Can you provide c++ sample code?
Also, are there any examples to run on Ubuntu?

I have a real time updated chart with very large data size and I am facing the slow client problem. i.e. The data sending speed is faster than the data receiving and handling speed which causes memory growing up issue. I am trying to use Web Workers to increase the data handling speed in frontend. I have found a related post:

https://www.scichart.com/questions/wpf/is-xydataseries-safe-to-being-changed-in-a-separate-thread

It seems possible to update XyDataSeries in the background thread with WPF. My UI is built with NextJS. I tried to use Web Workers to implement multiple threads. But I found that it can’t pass the SciChartSurface or XyDataSeries to the worker thread. Could you show me an example on how to update XyDataSeries in the worker thread with Web Workers?

I recently upgraded SciChart from version 2 to version 3.0.266. It was working fine. But I got error (please refer to the attached screenshot) when I try to run my application today. It’s so strange as it worked fine yesterday and I didn’t make any codes change today.

How to update the text Annotation in JavaScript. I can add the new Text annotation but I can’t update the old text Annotation. whether we have any option in sci chart for JavaScript.

Hi,

We use SciChart extensively in our WPF applications and make use of CustomRenderableSeries, writing all kinds of different lines and bitmaps directly to the IRenderContext2D depending on the point metadata.

We’re now looking at doing something similar in JavaScript, but can’t find any examples of this kind of customisation in the documentation. In the JavaScript library, is it possible to draw directly to a ‘canvas’ in the same way as in the WPF version? If so, could you please point to an example?

Many thanks,

Graham.

How can we change the color(Red) of custom box annotation when it is clicked .
thanks

I have combed through KB articles and other documentations and samples here and SO, but I am not able to fix the issue. I am desperate for any help.

I have a react app that shows the chart, but at the top of the page, I have a header section and the remaining height is filled with Chart. All the samples and answers that I have seen thus far has no header section on the page. So the chart is 100% filled within it’s container. But, in my case the chart does not fit its container width & height and I end up with a scroll-bar. This is especially evident when you maximize the page (Chrome maximize window).

I am on Windows 10.

I have attached the code and a screen-shot of what the resulting page in Chrome. I have tried with and without CSS and it made no difference in terms of chart filling its container.

React Code:

import { useCallback, useEffect, useState } from 'react';
import { createRoot } from 'react-dom/client';
import './Chart-styles.scss';
import { SciChartSurface } from 'scichart/Charting/Visuals/SciChartSurface';
import { NumericAxis } from 'scichart/Charting/Visuals/Axis/NumericAxis';
import { getSciChartLicense } from '../common/chartUtils';

const Chart = () => {
const [chartId] = useState('line-chart');

const initChartAsync = useCallback(async () => {
    const { sciChartSurface, wasmContext } = await SciChartSurface.create(chartId);

    const xAxis = new NumericAxis(wasmContext);
    const yAxis = new NumericAxis(wasmContext);
    sciChartSurface.xAxes.add(xAxis);
    sciChartSurface.yAxes.add(yAxis);
}, []);

useEffect(() => {
    SciChartSurface.setRuntimeLicenseKey(getSciChartLicense());
    initChartAsync()
        .catch(error => {
            console.error('ChartRenderer | useEffect | initChartAsync failed!', error);
        });
}, [chartId]);

return (
    <div className="App">
        <div className='App-header'>
            <h2>Chart Header</h2>
            <h3>Chart Sub-Header</h3>
        </div>
        <div
            id={chartId}
            style={{width: '100%', height: '100%'}}
        />
    </div>
);
};

const container = document.getElementById('app');
const root = createRoot(container!);
root.render(<Chart/>);

Chart-Style.scss

#app {
    display: flex;
    flex-flow: column nowrap;
    margin: 0;
    padding: 0;
}

.App {
    flex: 1 1 auto;
    display: flex;
    flex-flow: column nowrap;
    text-align: center;
}

.App-header {
    flex: 0 1 auto;
    display: flex;
    flex-flow: column nowrap;
    background-color: #855b24;
    color: white;
    h2 {
        background-color: #2e2e2d;
        flex: 0 1 auto;
        margin: 0;
        padding: 2px;
    }
    h3 {
        background-color: #5c5c5b;
        flex: 0 1 auto;
        margin: 0;
        padding: 2px;
    }
}

#line-chart {
    flex: 1 1 auto;
}

I have a real time updated chart and users can add annotation to the chart. The position of the annotation will be updated with the chart data. I would like to stop updating the annotation position while user dragging the annotation. So I added a flag (e.g. isDragging) to the annotation dragStarted and dragEnded events. The isDragging flag will be set to true in dragStarted and then set to false in dragEnded. I will check this flag before updating the annotation position.

Here’s the problem, the annotation dragStarted event will be triggered when users do panning in the chart. But the dragEnded will not be triggered in this case. It breaks my plan to stop updating the annotation position as the isDragging will be incorrect. Is it a bug that the annotation dragStarted event (but not the dragEnded event) triggered when panning?

Hello.

The graph is automatically stretched in width. How to do the same in height?

Video