Relationship Matrix - This shows the A matrix for the stud "Roan Gauntlet" from Wrights original 1922 paper on inbreeding, with the "A" matrix values are shown as fractions
To view this report, choose Relationship Matrices from the report selector (at the top of the report pane) in the main window.
PedScope will compute and display various relationship matrices, such as the 'NRM' or 'A' matrix of additive genetic relations, between any group of related animals. The matrix is calculated for all of the source animal records, plus a given depth of their ancestors and, optionally, their descendants. The matrix can be saved (i.e. exported) including to spreadsheets.
When the report pane is set to display relationship matrices, several extra pulldown menus are available below the report selector:
Below the displayed matrix are some further controls:
When showing a relationship matrix the property pane to the right will display the details of the selected cell. Just click a matrix cell to have the details of the row + column animals displayed.
There are various other ways you can customize the display of matrices:
Memory Usage: It is important to be aware that computing relationship matrices can require a very large, potentially huge, amount of memory. A relationship matrix contains as many rows and columns as the number of animals, and their ancestors and descendants that you have chosen to display. E.g. lets say you choose to display the additive matrix for 10 particular animals, plus 16 generations of their ancestors. And that once those ancestors have been found, this results in a total of 10,000 animals. A matrix with 10,000 rows and columns contains 100,000,000 cells. If each cell takes, say 8 bytes of storage (typical for a floating point number on many systems), this would be 800 Mb memory. Which is a lot. Whilst the program can (and does) use optimizations where it can to reduce the memory footprint (e.g. relationship matrices are symmetric, which at a stroke halves the memory requirement), it is still very easy to run out of memory. You can see the amount of memory used in the stats line displayed above the property pane when you have a relationship matrix visible. E.g. "N=1,696, memory=6.1Mb" says that the relationship matrix contains 1,696 rows + columns, and occupied 6.1Mb main memory. The program will not crash if you try to use more memory than is available, but it might become very slow or you might see an error message. Note also that if you compute the genomic relationship matrix, this will occupy 4 times as much memory for the same number of animals, because it has 2 rows and 2 columns for each animal.
PedScope is a product of Tenset Technologies Ltd, © 2011-14 All Rights Reserved. v2.4.01, June 2014