@ptrblck
l=tensor([100,  12,  75,  55])
i have this tensor list
and i want to use it his way
X[:,- l:]
but i will get an error saying only
 only integer tensors of a single element can be converted to an index
basically i want to mask certain range of labels/outputs while computing the loss/metric.
eg. for first tensor element in Batch i  want to use elements starting only from -100:,for second element  from -12: and like wise