On Thursday, 26 February 2015 at 23:25:22 UTC, Ali Çehreli wrote:
On 02/26/2015 12:01 PM, Andrey wrote:> HI guys!!!
>
> Have a problem with 3d array memory allocation in next code:
>
> //////////////////////////////////////////////////////////
> class NeuronNet(T, const uint layersNum)
> {
> T[] _inputs;
> T[][layersNum - 2] _hidden;
> T[] _outputs;
> T[] _target;
>
> //waights [col][row][dimension]
> T[][][layersNum - 1] _waightsArray;
(Unrelated: That may be a typo if its actually "weights".)
> this(in uint[] nodesArr)
> {
> //values init
> _inputs = new T[nodesArr[0]];
> _outputs = new T[nodesArr[$-1]];
>
> for(uint j = 0; j < layersNum - 2; j++)
Better:
foreach (j; 0 .. layersNum - 2)
> {
> _hidden[][j] = new T[nodesArr[j + 1]];
You have extra [] up there. This is equivalent:
_hidden[j] = new T[nodesArr[j + 1]];
The reason is, _hidden[] means "the entire _hidden slice"
anyway. So, the empty [] has no meaning at all.
> }
> //waights init
> for(uint i = 0; i < layersNum - 1; i++)
> {
> _waightsArray[][][i] = new T[][nodesArr[1+i]];
Same there:
_waightsArray[i] = new T[][nodesArr[1+i]];
> for(uint ii = 0; ii < nodesArr[1+i]; ii++)
> {
> _waightsArray[][ii][i] = new T[nodesArr[i]];
You want to set ii'th element of the i'th element, right? This
is the right way to do it in D:
_waightsArray[i][ii] = ...
Unlike C and C++, the array syntax is natural in D. In other
words, it is not "inside out".
T[] --> A slice of Ts
T[][] --> A slice of T slices
T[][][layersNum - 1] --> A number of those
So, _waightsArray[i] is one of the slices that you've just set
in the previous for loop.
Ali
I very much appreciate. The author of D-book respond to me.
THANKS VERY MUCH!!!!!
