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The STRAF Book

7 File conversion

As STRAF is a web application and can be used simultaneously by multiple users, computing resources are limited. Therefore, the most computationally intensive analyses are not available in STRAF. Also, allele frequencies sometimes have to be imported to other software for kinship analysis or DNA profile interpretation including mixtures.

In order to ease the path to other software, file conversion utilities have been implemented. It is possible to convert the input file to the Genepop, Arlequin and Familias formats. They are all available in the File conversion tab of the application.

7.1 How to convert a file in STRAF

Once you have imported your file, it is straightforward to convert it to another format. You can go to the File conversion tab and click on one of the following buttons to download your genotypes in another format.

7.2 Genepop and Arlequin formats

Genepop (Rousset 2008) and Arlequin (Excoffier and Lischer 2010) softwares implement several population genetics methods, including ones that are part of standard forensics practice:

  • linkage disequilibrium computation

  • Hardy-Weinberg tests

STRAF currently implements these computations, however the ones implemented in Genepop are overall more reliable as they can rely on more permutations. They are overall preferable to the HW and LD tests implemented in STRAF.

7.3 Familias

Here a file containing allele frequencies is created. This file can be used in Familias (Kling, Tillmar, and Egeland 2014) to provide allele frequency reference data for relationship testing.