Affymetrix

AFFYMETRIX DEVELOPER NETWORK

Affymetrix® GRC Data File Format


GRC FILE

 

 Description
The GRC, grid control, file contains the set of feature coordinates associated with the B1 and B2 probes and unsynthesized features. The B1/B2 probes are those used for the checkerboard and border patterns. This file is used by the GCAST algorithm in the Tiling and HT software to determine those features that should be bright or dim and were not.

Format
The format of the GRC file is a binary file with data stored in big-endian format.

 The contents of the GRC file as defined as follows:

Item DescriptionType Size
1 Magic number. A value to identify the file type. The value is set to 129. char1 byte
2 The version number of the file. The version number is set to 1. char 1 byte
3 The number of columns of features on the array.int 4 bytes
4 The number of rows of features on the array.int 4 bytes
5 The number of B2 probes on the array.int 4 bytes
6 The number of B1 probes on the array.int 4 bytes
7 The number of non-synthesized features on the array. int 4 bytes
8 The X/Y coordinates of the B2 probes on the array. Array of X (unsigned short), Y (unsigned short) (2 bytes + 2 bytes) * #B2 probes.
9 The X/Y coordinates of the B1 probes on the array. Array of X (unsigned short), Y (unsigned short) (2 bytes + 2 bytes) * #B1 probes.
10 The X/Y coordinates of the non-synthesized probes on the array. Array of X (unsigned short), Y (unsigned short) (2 bytes + 2 bytes) * #non-synthesized features.