Nativescript-ui-feedback: Timeseries example for RadChart?

[brylie]

The example line hart is somewhat contrived, and represents a way to misuse line charts. Typically, line
charts connect a series of observations that are continuous in nature, such as timeseries data. Rather, this example data consists of discrete categories, which would be better represented as bar chart.

This feedback is not purely academic, as the example misses an opportunity to showcase proper timeseries datetime handling, often found in rich chart libraries.Please update the example to use more inappropriate data, and/or mention whether this chart library can handle timeseries data without significant developer effort.

[brylie]

I am using Plotly as a benchmark here, after coming up significantly short with several other charting libraries.

https://plot.ly/javascript/

Might it be possible to use Plotly as the recommended charting library, rather than going down the rabbit hole, which has considerable nuance, of creating yet another charting library?

[tgpetrov]

Hi @brylie
Thank you for the feedback.
Is this the example with the LineSeries presenting continuous data that you are looking for? Here's how it looks:

[brylie]

Yes, basically showing a date axis with a data axis (numeric). In general, each chart type is suitable for differing types of data, numeric, categorical, etc., so using the example data should be appropriate for the chart type. I also realize there is quite a lot of underlying complexity in date handling/rendering for timeseries charts, which is why it might be good to use an existing charting library that has already paved the way.

[tgpetrov]

Great, so if I understand correctly, we have an example of a LineChart using combination of Date and Number axes, but we need to improve docs and examples so that such examples are more easily discoverable. Also we should prefer more meaningful combinations of axes and series (i.e. connecting values in discrete categories with LineSeries is not the most popular scenario for these series)?

[brylie]

Yep, but I can't find the example you mention in the line chart documentation. Rather, the line chart documentation reuses the same sample data that is more appropriate for a bar chart example. I.e. there isn't a meaningful way to connect 'Germany', 'France', 'Bulgaria', etc. as they are distinct categories.

See: Data: Continuous vs. Categorical

[tgpetrov]

You are right. Thanks again for the feedback.

[djmgh]

I am also very confused by the choice of examples for LineSeries and SplineSeries. An example plotting an unordered list of x,y numbers would be appreciated... My attempts to use LinearAxis failed to plot the values on an Android device, but then I noticed it worked on iOS emulator. An update to the docs with an example using LinearAxis instead of CategoricalAxis would be great.

[brylie]

@tgpetrov would it be possible to integrate a more mature, and focused, charting library into NativeScript UI via JavaScript? For example, Plotly.js, ECharts, and TauCharts are all fairly mature with good APIs.

It sincerely seems that the NativeScript chart library is somewhat an afterthought, and it would be beneficial to defer to a project with holistic design and clear focus for data visualization.

[VladimirAmiorkov]

Hi @brylie ,

Simply integrating a JS library into the native rendering of the _nativescript-ui-chart_ is a relatively complex task. The current implementation is entirely custom both the logic and the rendering is done in native Objective-C code for iOS and Java for Android which means that there is no easy way to integrate a third party JS library which has been designed to use the DOM for rendering its elements. For now we are focused on resolving any ongoing issues with the _nativescript-ui-chart_ and we always welcome contributions via our DNA process that can be found here.