Stack type based

[eprata]

I am trying to use the based stack type for some of my TimeChart's. But I've noticed some behavior I can not understand.

I have two series pointing to the same stack (based type):

The code:

      stacks: {
          "stackA": {
              name: "A",
              type: "based"
          },

      },
      series: [
        {
            name: "Total",
            id: "serie1",
            type: "columns",
            data: {
                index: 1
            },
            style: { fillColor: color_verde_claro },
            stack: "stackA"
        },

          {
              name: "CVC",
              id: "serie2",
              type: "columns",
              data: {
                  index: 2
              },
              style: { fillColor: color_cinza_claro },
              stack: "stackA"
          },

The result:

If "total" is disabled:

If "CVC" is disabled:

The only reference I could find to the based type - I mean, some explanation about - was:

https://zoomcharts.com/developers/en/time-chart/introductory-topics/data-series.html

So, if the series are based to zero value... Why I can see a piece of the green one, when both of them are enabled? And if both have the same high, which one should be in the front and which one should be hidden by the other? Or, what is the expected behavior in this case?

[karlis]

What are the actual correct values? Is Total ~670 and CVC ~42?

[eprata]

Yes:

[karlis]

For the based stack type the order of the series is important. In your case what happens is that the "Total" column is drawn from 0 to 665. Now after this the CVC column is drawn from 665 down to 42. If you would add semi-transparent fill color, you would see that the columns overlap.

So in your case the easy workaround is to switch the series in the settings.

In version 1.14.4 (will be released shortly after I finish writing this) we changed this slightly so that Total column would be drawn from 0 to 665 but the CVC column would be skipped (the columns with positive values will never be drawn downwards).

We also discussed that in future we would either change the based type or add another type (which is more likely now that the based type will depend on the order and draw reasonable results) that would automatically reorder the values so that all of them are always visible.

[eprata]

I don't know if you consider some suggestions, but...

Also, it would really be nice, at least in my case, if I could have two types of stacks in only one stack. Let me see if I can explain better:

For example, I am trying to show the total of pacients and then, show the portion of them that use some type of medicine... Let's say I am interested only in the A, B and C drugs...
So, what I would like to have: the serie of the total of pacients and the number of pacients using A, B and C - each one as a separated serie... But, A, B and C like a stack normal or proportional, but drawn over the stack of the total of pacients...

[karlis]

In these scenarios we ourselves usually

a) show the total number as a line series behind the columns.
b) calculate an "Others" value in the data source. This however would not work as you described if you want to toggle the series using legend.

Essentially what is needed is the ability to draw multiple stacks one over the other instead of only side-by-side. This would allow the scenario you described.

[eprata]

Ok, thanks for the idea.

Just to be sure: until now, "the ability to draw multiple stacks one over the other instead of only side-by-side" is not possible yet, right?

[karlis]

Yes, that is currently not yet possible.