Adding an horizontal line to each trace

I have rephrased my post, plus adding lines of codes:


Assuming a graph with 4 lines, coded using the feature traces.append(), I would like to know if it is possible to add a shape on the y axis, a straight horizontal line, but for each of the four lines.

Basically, It would be a straight line on the โ€œtraceโ€ part, not on the layout.

What I am looking to do itโ€™s plotting the minimum of each line. So I would end up having 8 lines, 4 with my time series, and 4 horizontal lines with the minimum of each of the time series.

@ruhkog Please put an image of a manual plot to understand better what are you talking about, because
from your above presentation itโ€™s not clear what do you mean by horizontal line for each four lines. Then we could suggest how to define the horizontal lines.

I changed my way of approaching the problem. I am just adding a line on the trace.append() part, and using legendgroup to make sure it stays synchronized with my main line.