Options to modify the opacity and width of each line

[shangzTJ]

Hi, is it possible to modify the opacity and width of each line?

[danthe3rd]

Hi @shangzTJ

Several questions to help you better:

• Which lines are you talking about? The ones of the parallel plot, or the ones from the XY plot?
• How do you use hiplot? (notebook? NPM package? within streamlit? with the included webserver ...?)

Thank you :)

[shangzTJ]

Thank you for your quick reply @danthe3rd
The line refers to those in the parallel plot，and Hiplot is used in streamlit.

[danthe3rd]

Indeed there is no way to change that in the parallel plot. I can work something out tho.
Can you tell me more about what you are trying to achieve? We want to get the best visualisation by default if possible

[shangzTJ]

Thanks.
I have thousands of data to be visualized in parallel plot, which induces the line clutter problem. I attempted to solve the problem by calculating line densities (link) and adjusting the corresponding opacity or width.
As far as I know, many parallel plot applications require the configuration of line opacities, so will this option be provided in the future?

[danthe3rd]

Sure I could add that. You want a global opacity, or a different opacity value for each line?
Do you compute the opacity as a function of the number of rows?

My concern is that you might want to have a different opacity depending on the number of rows displayed (when slicing for instance).

EDIT: Currently, opacity is computed as d3.min([2/Math.pow(n,0.3),1]) with n the number of rows displayed

[shangzTJ]

(1) A different opacity value for each line is preferred, and is expected to be specified by a column in the input DataFrame.
(2) The opacity values are not calculated based on the number of all rows.