Point-and-figure chart function issue

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I used the point-and-figure chart function of mplfinance and have two issue. One is that the point-and-figure chart does not strictly follow the 1:1 ratio to draw each cell, that is, we can think of the canvas as a grid of countless 1:1 squares, and each X or O appears in the grid in order, no matter if it is enlarged or reduced our chart, this ratio is no change. The purpose of this is that the point-and-figure chart has an important technology called the “45-degree trend line”. We can use it to judge the later trend. If the point-and-figure chart is not drawn to scale, for example, there is a certain distance between the two columns, then the “45-degree trend line” loses its meaning.

The second issue is could the mplfinance can add a function, that is, the lines of every 5 rows and every 5 columns are thickened, just like the real graphics drawn on paper.

Thanks a lot for nice work of mplfinance.

Point-and-figure on paper sample:

[http://www.forexalchemy.com/wp-content/uploads/2015/04/point-and-figure-chart.jpg](url)

Start by locating mplfinance's point-and-figure chart function and reproduce both reported behaviors with a small chart. Check how cell dimensions and column spacing are calculated, then define tests for a fixed 1:1 grid and for thicker lines every five rows and columns. Done means the chart preserves the grid ratio at different sizes and renders the requested paper-style guides.

Written by the indexing model from the issue text.