Evoker

Evoker is a graphical tool for visualizing genotype intensity data in order to assess genotype calls as part of quality control procedures for genome-wide association studies.

It provides a solution to the computational and storage problems related to being able to work with the huge volumes of data generated by such projects by implementing a compact, binary format that allows rapid access to data, even with hundreds of thousands of observations.

[The Wellcome Trust Sanger Institute]

Downloads

Evoker is an open source project hosted on SourceForge.

SourceForge downloads

License

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

FAQs

Q: How do I launch Evoker for Windows?
A: Download Evoker from SourceForge (see 'Downloads') and unzip the install bundle then simply double click the Evoker.exe file in win folder.

Q: How do I launch Evoker for Mac?
A: Download Evoker from SourceForge (see 'Downloads') and unzip the install bundle then simply double click the Evoker.app file in mac folder.

Q: How do I launch Evoker for Unix?
A: Download Evoker from SourceForge (see 'Downloads') and unzip the install bundle then simply double click the Evoker.jar file in other folder.

Q: How do I load a remote data set?
A: To load a remote data set select Connect to remote server from the File menu. Fill in the resulting pop-up with the following information:

  • Host is the name of the computer that the data is stored on
  • Remote directory is the absolute path of the data directory on the host machine (an easy way to get the correct string to enter in the data connection dialog for the remote directory is to login to that machine, change to that directory and run the pwd command)
  • Local directory can be any directory on the machine you are working on that you are happy to store temporary files generated by Evoker in (make sure you do not select a directory that contains important files as Evoker can delete all the files in this folder each time a new data set is loaded)
  • Username and Password should be what you use to access the remote computer

Q: How do I generate a marker list?
A: An Evoker marker list is simply a plain text file containing each marker ID (the ID you use must match the ID used in the collection bim file) on a separate line.

Q: Where will my scores be saved?
A: Evoker writes the scores you have recorded into a file with .scores appended to the name of the marker list you loaded.

Q: How do I use the zoom feature?
A: You can zoom in and out of the plot either using the right click menu or by clicking and dragging (down and to the right creates a 'zoom in box', while up and to the left zooms back out again).

Q: How can I identify the sample name of a point on the plot?
A: Holding the pointer over the point of interest will show which sample corresponds to that point.

Q: How do I save an image of all the displayed plots?
A: To save a png image of all of the plots displayed in the Evoker window select Save SNP Plots from the File menu and enter your desired save location.

Q: How can I save an image of an individual plot?
A: To save an image of an individual plot right click on the plot of interest and select Save as… from the menu that appears then select your save location.

Q: What do I do if Evoker runs out of memory?
A: If Evoker needs more memory to load a data set then users can launch the program with additional memory from the command line by issuing the following command (increasing the –Xmx value as necessary):

java -Xmx1024m -jar Evoker.jar

Q: Where can I find the Evoker documentation?
A: The evoker documentation can be downloaded from SourceForge and is also included in the download package.

Contact

For questions or comments, please contact James Morris or Jeff Barrett.