change gpu id

[hourieh-jamali]

hi
I have a question about running this code on system has one gpu,my system has a GeForce GTX 980 Ti GPU and I comment MPI_LIB & MPI_INCLUDE in config file, and as a wrote in expriments part I have to change GPU device id in these files:
train_model() and extract_features() of scripts/rountines.sh
main() of tools/compute_impact_score.py**
how to change Gpu Id in these parts?
I change train_model() method like as this

Training

if [[ $# -eq 2 ]]; then
GLOG_logtostderr=1 ${CAFFE_DIR}/build/tools/caffe train
-solver ${solver} -gpu 0 2>&1 | tee ${log}
else
GLOG_logtostderr=1 ${CAFFE_DIR}/build/tools/caffe train
-solver ${solver} -weights ${pretrained_model} -gpu 0 2>&1 | tee ${log}
but I don't know how to change extract_feature() and compute_impact_score..py parts?
thank you