Leeds Chart Generator

This app, which creates a Leeds Chart from Ancestry.com DNA data, was developed by David Nowotnik, one of our members, using Claude 3.5 Sonnet AI. Instructions for using the app are displayed lower down on this webpage.  Updated November 26, 2024

This app has not been extensively tested. If you have a problem, or have any comments or suggestions, please write to: colleyvillegenealogy@gmail.com

INSTRUCTIONS

The Leeds Method was developed by Dana Leeds to cluster autosomal DNA matches into groups. Ideally, it produces four groups in which each group is related to one of your grandparents. Often, the results don't provide this ideal situation, but the Leeds method can still help you a lot in determining how your DNA matches are related to you.

The first step in using this application is to capture your DNA match list from Ancestry.com. On your DNA match list page, scroll to the bottom and select whether you want to show 20 or 50 matches per page. A Leeds analysis typically uses your DNA matches in the range of 90-400cM, and you can use Ancestry's filters to show just the matches in this range. But, you can choose any range, or no filter, if you want.

On the Ancestry.com page listing DNA data, click CTRL-A then CTRL-C (CMD-A and CMD-C on a Mac) to copy the data to clipboard. Click the paste box below the "Leeds Chart Generator" title (above) to activate it, then click CTRL-V (or CMD-V) to paste the data into the paste box. You should get a 2-column table of the data. If you want to add more matches to this list, click 'yes' in the pop-up box; otherwise click 'no' and the app then switches to shared matches.

Note that with Ancestry.com's new data format, pressing CTRL-A does not always select all data on the page. It is recommended that you scroll to the end of the page and click blank space near the bottom of the page, then press CTRL-A. For the DNA match list, you will need to scroll to the bottom of the page to increase the listing amount from 20 to 50 matches per page.

In the Leeds method, the general rule is that you start with the highest cM match in the 90-400cM range. The app will highlight this match for you. You can capture the shared match data for this match, or another if you decide on a different starting point. Go to the shared match listing and again do CTRL-A and CTRL-C to capture data to the clipboard. Return to the app, and activate the paste box, then CTRL-v to paste the data into the paste box. You'll get your first column of matches. 

The next shared match is the highest cM below 400cM that is unassigned in any group. Again, the app highlights it for your convenience. Capture the shared match data for this match as before, and add it to the app, as before. You'll get a 2nd column. Repeat, and you'll get 3rd and 4th columns.

The app should work whether your shared match data is the 'regular' type or the 'Pro' type.

You may wish to merge columns. Click the merge button, and select which column that you merge from and which you want to merge into, then press OK. In the standard Leeds method, there is just one color per column, but the app keeps color from both columns, as this may subsequently be helpful in analyzing the chart. If you make a mistake and want to delete a shared match column, there is a 'delete last column' button.

Click the title of a shared match column, and you will get a dialog box to change the title. As space is limited in the title box, keep it short!

There are two copy buttons. One is used to copy the data to clipboard, so that it can be pasted into a spreadsheet for further analysis. The other copy button places an image of the chart onto the clipboard. At present, security restrictions on this Google Sites website prevent the use of these Copy buttons. You can request a standalone version of this app for personal use, in which these functions are available.