Selects the GPU device to use for computation. This is only useful on a
machine equipped with multiple GPU devices. The numbering starts at 0
and is assigned by the CUDA capable driver.
Choosing a device can only be done before any other GPU operation and
only once per thread.
Usage
chooseGpu(deviceId = 0)
Arguments
deviceId
an integer >= 0 designating the GPU to use for computation.
Value
chooseGpu should print out an integer specifying the device id chosen or
an error message.