some bugs of transform.merge()

[ZongweiZhou1]

when i run the provided example of transform.merge():

f = transform.merge{
        [1] = function(x) return 2*x end,
        [2] = function(x) return x + 10 end,
        foo = function(x) return x / 2 end,
        [4] = function(x) return x - x end
   }
f(3)

there is always the error information:

...hou/torch/install/share/lua/5.1/torchnet/utils/table.lua:123: attempt to index a number value

i find that the function 'f()' call the function 'utils.table.mergetensor(newz)', and then the line 123 of utils.table attempt to operate 'newz[1]:size()', but here the newz[1] is a number,thus the conflict is produced.

maybe the line 144 can be fixed as 'return newz' ?

[lvdmaaten]

You should never use a table with text keys as input into transform.merge: such a hashtable has no guarantees on the order of elements when you iterate over it with pairs(), making the behavior of your example undefined. Please use a table with numerical indexes (a table you can iterate over with ipairs()) instead.