In order to more easily compare correlation of scatter-plots to identity mapping, it would be great to have the first diagonal line being plotted just as the x-y-grid in the background of the plot.
I played with
fig.update_layout(
shapes=[
dict(
type= 'line',
yref= 'y', y0=-1000, y1= 1000,
xref= 'x', x0=-1000, x1= 1000
)
])
but that obviously changes the plot extent. I chose arbitrarily high extent in order to cover all real value ranges.
I guess, there must be a more straight-forward way to add graph elements in the background (not taking any own extent)?