Null values on a line chart about dimple

[johnkiernander]

As of version 2.0 this now draws ok, but it treats null as zero. The way I see it we can either :

• treat as zero
• ignore it so the line goes straight between the points on either side
• break the line in 2 pieces

I'm not crazy about the last option as it would look bad where a single point is left behind. I'd probably vote for option 2 (even though option 1 means no work!).

I'm interested to get anybody else's thoughts on this?

All of the three behaviors are valid on some use cases, but

• to achieve 1, you pass a zero
• to achieve 2, you don't pass that point
• to achieve 3, you pass a null - and hope the library does its job

I vote for 3, that's sometimes very useful.
e.g. when data is like (100, 150, unknown, unknown, unknown, unknown, unknown, 200, 150). Yes, that happens.

[dss010101]

i agree with sarcidiacono. Infact, i think there should be an option that allows you to decide how you want nulls to be treated. Right now i'm looking for a way to print dates on the x-axis, but no value. the use case i'm struggling with is that a page has two charts, and i want the dates of the two to be the same..even if no data exist for one of the time-series. Another use-case: data-integrity checks - i want users to see gaps in data if they are the master of those data.

[RichardNeill]

I have a suggestion - at least for a bar chart. Let's say we've measured 50 different branches, and got a score for each of them. Some branches scored 0. One branch didn't return their data. So... how can we represent the latter? We could remove the bar entirely, but I think there is a case for explicitly drawing a representation of "this branch failed to submit a value".

At the moment, dimple does the "least surprise" approach and treats the null as a zero when drawing the bar height.

I suggest re-formatting the bar label (probably as a strikethrough), and adding the word "NULL" into the tooltip where it currently shows the value of 0. Is there a neat way to do this?

[RichardNeill]

With a bar chart, a zero-height bar is at least invisible. But with a bubble, the bubble is now shown as zero. Worse, the tool-tip shows that the value is "0", when it should actually say "null".