Confusion, on my part, about how to change chart legend... series labels?

Confusion, on my part, about how to change chart legend... series labels?

I know you can initialize a chart with labels, data, series information from scratch in a payload, but I have a chart that has received data and I just want to change the legend, after the chart is populated, for an already defined set of series.

I figured, [{'labels': theLabels}];, where theLabels is just an array of strings. But all I get is 'Bad data inject' which suggests you can't update or change labels once a series is established? Tell me there is a way?

I have a ui-table that is updated dynamically, with a list of web sites, each site is monitored via ping and other statistics, the operator can change this table at anytime, so I never know the list of sites before hand. Even then, sending the raw data points to a ui-chart object is easy, just set the topic and done. But the default labels are 0,1,2, etc. or some such. How do I change such? Wonder why the legend does not just use the topic strings? That would make the labeling easy!

As far as I know, I can't do [{"labels":, "data":[], "series":}] as a payload, initialization of the chart, would blow out all the data already present in the chart?

As far as I have seen it does use the topic string, can you share a simple example flow demonstrating the issue.