Allow only positive values as an interval except -1
Allow only positive values as an interval except -1

chainer/chainer,ktnyt/chainer,chainer/chainer,wkentaro/chainer,hvy/chainer,okuta/chainer,cupy/cupy,chainer/chainer,ysekky/chainer,aonotas/chainer,wkentaro/chainer,niboshi/chainer,keisuke-umezawa/chainer,keisuke-umezawa/chainer,cupy/cupy,keisuke-umezawa/chainer,cupy/cupy,cupy/cupy,anaruse/chainer,niboshi/chainer,hvy/chainer,hvy/chainer,hvy/chainer,jnishi/chainer,pfnet/chainer,chainer/chainer,jnishi/chainer,wkentaro/chainer,ronekko/chainer,jnishi/chainer,rezoo/chainer,okuta/chainer,tkerola/chainer,okuta/chainer,ktnyt/chainer,delta2323/chainer,niboshi/chainer,jnishi/chainer,keisuke-umezawa/chainer,kiyukuta/chainer,kashif/chainer,ktnyt/chainer,wkentaro/chainer,okuta/chainer,niboshi/chainer,ktnyt/chainer