What is the name of this line summary of heatmap I have asked on SO about some implementation details of my problem. But I have realized that it is hard to ask (and search) if you do not know the name of the graph. Because this community is more about statistics I am asking here - how is the name of the following variant of a data-visualization.
I have an experiment, where for every location (1-100) a value of Y variable changes over time. I want to show this with a 2d graph, where X-axis correspond to the locations (1-100) and Y-axis correspond to the average value of Y for this location in the chosen time interval (e.g. for yesterday).
EDIT: I am talking about a line that is overlayed the heatmap. Every point in a line is average value of the corresponding column. Maybe, this is to trivial to have a name?

 A: I would guess that this visualisation does not have a name. And there's a good reason for that - this is just not a good way to visualise data and should be avoided. It breaks some basic principles of visualisation.

*

*If you use time and location as your X- and Y- axes in a 2D plot, readers will reasonably conclude that any line you draw indicates the relationship between time and location. Using a line to indicate some property of an implicit third dimension (colour) is unintuitive.

*'Locations' isn't continuous but is shown as though it is. Even if there is some natural ordering to the locations, this depiction (both the colour variation and the continuous line) paints a misleading picture unless these are evenly spaced sampling locations (in which case location = distance).

There are much better ways to visualise this data. It's possible to indicate both the time series and the overall means on one plot but I would recommend splitting these into two.
First, the time series. I would recommend a joy plot to depict them if there aren't too many locations. Small multiples line plots are another option.
Second, use a Cleveland dot plot to indicate the means.
