utils.py 文件源码

def getlearningrate(epoch, opt):
    # update lr
    lr = opt.LR
    if opt.lrPolicy == "multistep":
        if epoch + 1.0 > opt.nEpochs * opt.ratio[1]:  # 0.6 or 0.8
            lr = opt.LR * 0.01
        elif epoch + 1.0 > opt.nEpochs * opt.ratio[0]:  # 0.4 or 0.6
            lr = opt.LR * 0.1
    elif opt.lrPolicy == "linear":
        k = (0.001-opt.LR)/math.ceil(opt.nEpochs/2.0)
        lr = k*math.ceil((epoch+1)/opt.step)+opt.LR
    elif opt.lrPolicy == "exp":
        power = math.floor((epoch+1)/opt.step)
        lr = lr*math.pow(opt.gamma, power)
    elif opt.lrPolicy == "fixed":
        lr = opt.LR
    else:
        assert False, "invalid lr policy"

    return lr