USAGE: [result, ivx]=iViewX(cstr, ivx [, params])
iViewX requires as input:
1. a command string
2. a structure with iViewX default values.
cstr: command to execute
ivx: structure holding default information
params: optional parameters to pass on with the command
returns:
result: any result produced by the command
ivx: structure with default information (that may have been modified)
Psychtoolbox/PsychHardware/iViewXToolbox/iViewX.m