How do you get two lines with unique yaxes to begin at the same vertical point

Dash Python
1

I have just finished creating your basic Draw the performance of one Stock and one Market Index on the same chart.

Screen Shot 2020-05-08 at 9.49.52 PM
Screen Shot 2020-05-08 at 9.49.52 PM1596×906 98.3 KB

The problem is that to properly compare the performance between the two, they both need to start at the same vertical starting point on the left side. Dash is drawing them independently, most likely with consideration for best fit.

How can you define both lines to start at the same vertical point on the left side?

3

I think the best way to do it now is to chart percentage gain. Both values will be 0 on the left and the graph will be fitted to the gain or fall of the lines. The work will be to get the prices correct as a secondary axis but that should be way easier than the other way around.