/// <summary>
/// Intended for use with data augmentation
/// </summary>
/// <param name="volume">Input volume</param>
/// <param name="crop">Size of output</param>
/// <param name="dx">Offset wrt incoming volume, of the shift</param>
/// <param name="dy">Offset wrt incoming volume, of the shift</param>
/// <param name="flipLeftRight">flip left/right</param>
/// <returns></returns>
public static Volume Augment(this Volume volume, int crop, int dx = -1, int dy = -1, bool flipLeftRight = false)
{
if (dx == -1)
{
dx = Random.Next(volume.Width - crop);
}
if (dy == -1)
{
dy = Random.Next(volume.Height - crop);
}
// randomly sample a crop in the input volume
Volume w;
if (crop != volume.Width || dx != 0 || dy != 0)
{
w = new Volume(crop, crop, volume.Depth, 0.0);
for (var x = 0; x < crop; x++)
{
for (var y = 0; y < crop; y++)
{
if (x + dx < 0 || x + dx >= volume.Width || y + dy < 0 || y + dy >= volume.Width)
{
continue; // oob
}
for (var depth = 0; depth < volume.Depth; depth++)
{
w.Set(x, y, depth, volume.Get(x + dx, y + dy, depth)); // copy data over
}
}
}
}
else
{
w = volume;
}
if (flipLeftRight)
{
// flip volume horziontally
var w2 = w.CloneAndZero();
for (var x = 0; x < w.Width; x++)
{
for (var y = 0; y < w.Height; y++)
{
for (var depth = 0; depth < w.Depth; depth++)
{
w2.Set(x, y, depth, w.Get(w.Width - x - 1, y, depth)); // copy data over
}
}
}
w = w2; //swap
}
return(w);
}
public override Volume Forward(Volume input, bool isTraining = false)
{
this.InputActivation = input;
var outputActivation = new Volume(this.OutputWidth, this.OutputHeight, this.OutputDepth, 0.0);
#if PARALLEL
Parallel.For(0, this.OutputDepth, depth =>
#else
for (var depth = 0; depth < this.OutputDepth; depth++)
#endif
{
var n = depth * this.OutputWidth * this.OutputHeight; // a counter for switches
var x = -this.Pad;
var y = -this.Pad;
for (var ax = 0; ax < this.OutputWidth; x += this.Stride, ax++)
{
y = -this.Pad;
for (var ay = 0; ay < this.OutputHeight; y += this.Stride, ay++)
{
// convolve centered at this particular location
var a = double.MinValue;
int winx = -1, winy = -1;
for (var fx = 0; fx < this.Width; fx++)
{
for (var fy = 0; fy < this.Height; fy++)
{
var oy = y + fy;
var ox = x + fx;
if (oy >= 0 && oy < input.Height && ox >= 0 && ox < input.Width)
{
var v = input.Get(ox, oy, depth);
// perform max pooling and store pointers to where
// the max came from. This will speed up backprop
// and can help make nice visualizations in future
if (v > a)
{
a = v;
winx = ox;
winy = oy;
}
}
}
}
this.switchx[n] = winx;
this.switchy[n] = winy;
n++;
outputActivation.Set(ax, ay, depth, a);
}
}
}
/// <summary>
/// Intended for use with data augmentation
/// </summary>
/// <param name="volume">Input volume</param>
/// <param name="crop">Size of output</param>
/// <param name="dx">Offset wrt incoming volume, of the shift</param>
/// <param name="dy">Offset wrt incoming volume, of the shift</param>
/// <param name="flipLeftRight">flip left/right</param>
/// <returns></returns>
public static IVolume Augment(this Volume volume, int crop, int dx = -1, int dy = -1, bool flipLeftRight = false)
{
if (dx == -1)
{
dx = Random.Next(volume.Width - crop);
}
if (dy == -1)
{
dy = Random.Next(volume.Height - crop);
}
// randomly sample a crop in the input volume
Volume w;
if (crop != volume.Width || dx != 0 || dy != 0)
{
w = new Volume(crop, crop, volume.Depth, 0.0);
for (var x = 0; x < crop; x++)
{
for (var y = 0; y < crop; y++)
{
if (x + dx < 0 || x + dx >= volume.Width || y + dy < 0 || y + dy >= volume.Width)
{
continue; // oob
}
for (var depth = 0; depth < volume.Depth; depth++)
{
w.Set(x, y, depth, volume.Get(x + dx, y + dy, depth)); // copy data over
}
}
}
}
else
{
w = volume;
}
IVolume result = w;
if (flipLeftRight)
{
result = w.Flip(FlipMode.LeftRight);
}
return(result);
}
public static Volume Flip(this Volume volume, FlipMode mode)
{
Volume result = volume;
if (mode == FlipMode.LeftRight || mode == FlipMode.Both)
{
// flip volume horziontally
var w = volume.CloneAndZero();
for (var x = 0; x < volume.Width; x++)
{
for (var y = 0; y < volume.Height; y++)
{
for (var depth = 0; depth < volume.Depth; depth++)
{
w.Set(x, y, depth, volume.Get(volume.Width - x - 1, y, depth)); // copy data over
}
}
}
result = w; //swap
}
if (mode == FlipMode.UpDown || mode == FlipMode.Both)
{
// flip volume horziontally
var w = volume.CloneAndZero();
for (var x = 0; x < volume.Width; x++)
{
for (var y = 0; y < volume.Height; y++)
{
for (var depth = 0; depth < volume.Depth; depth++)
{
w.Set(x, y, depth, result.Get(x, volume.Height - y - 1, depth)); // copy data over
}
}
}
result = w; //swap
}
return(result);
}
public override Volume Forward(Volume input, bool isTraining = false)
{
this.InputActivation = input;
var outputActivation = new Volume(this.OutputWidth, this.OutputHeight, this.OutputDepth, 0.0);
#if PARALLEL
Parallel.For(0, this.OutputDepth, depth =>
#else
for (var depth = 0; depth < this.OutputDepth; depth++)
#endif
{
var n = depth * this.OutputWidth * this.OutputHeight; // a counter for switches
var x = -this.Pad;
var y = -this.Pad;
for (var ax = 0; ax < this.OutputWidth; x += this.Stride, ax++)
{
y = -this.Pad;
for (var ay = 0; ay < this.OutputHeight; y += this.Stride, ay++)
{
// convolve centered at this particular location
var a = double.MinValue;
int winx = -1, winy = -1;
for (var fx = 0; fx < this.Width; fx++)
{
for (var fy = 0; fy < this.Height; fy++)
{
var oy = y + fy;
var ox = x + fx;
if (oy >= 0 && oy < input.Height && ox >= 0 && ox < input.Width)
{
var v = input.Get(ox, oy, depth);
// perform max pooling and store pointers to where
// the max came from. This will speed up backprop
// and can help make nice visualizations in future
if (v > a)
{
a = v;
winx = ox;
winy = oy;
}
}
}
}
this.switchx[n] = winx;
this.switchy[n] = winy;
n++;
outputActivation.Set(ax, ay, depth, a);
}
}
}
#if PARALLEL
);
#endif
this.OutputActivation = outputActivation;
return this.OutputActivation;
}
public override Volume Forward(Volume input, bool isTraining = false)
{
this.InputActivation = input;
var depth = this.OutputDepth;
var outputActivation = new Volume(this.OutputWidth, this.OutputHeight, this.OutputDepth, 0.0);
// optimization branch. If we're operating on 1D arrays we dont have
// to worry about keeping track of x,y,d coordinates inside
// input volumes. In convnets we do :(
if (this.OutputWidth == 1 && this.OutputHeight == 1)
{
for (var i = 0; i < depth; i++)
{
var ix = i * this.GroupSize; // base index offset
var a = input.Weights[ix];
var ai = 0;
for (var j = 1; j < this.GroupSize; j++)
{
var a2 = input.Weights[ix + j];
if (a2 > a)
{
a = a2;
ai = j;
}
}
outputActivation.Weights[i] = a;
this.switches[i] = ix + ai;
}
}
else
{
var n = 0; // counter for switches
for (var x = 0; x < input.Width; x++)
{
for (var y = 0; y < input.Height; y++)
{
for (var i = 0; i < depth; i++)
{
var ix = i * this.GroupSize;
var a = input.Get(x, y, ix);
var ai = 0;
for (var j = 1; j < this.GroupSize; j++)
{
var a2 = input.Get(x, y, ix + j);
if (a2 > a)
{
a = a2;
ai = j;
}
}
outputActivation.Set(x, y, i, a);
this.switches[n] = ix + ai;
n++;
}
}
}
}
this.OutputActivation = outputActivation;
return(this.OutputActivation);
}
public override Volume Forward(Volume input, bool isTraining = false)
{
this.InputActivation = input;
var depth = this.OutputDepth;
var outputActivation = new Volume(this.OutputWidth, this.OutputHeight, this.OutputDepth, 0.0);
// optimization branch. If we're operating on 1D arrays we dont have
// to worry about keeping track of x,y,d coordinates inside
// input volumes. In convnets we do :(
if (this.OutputWidth == 1 && this.OutputHeight == 1)
{
for (var i = 0; i < depth; i++)
{
var ix = i * this.GroupSize; // base index offset
var a = input.Weights[ix];
var ai = 0;
for (var j = 1; j < this.GroupSize; j++)
{
var a2 = input.Weights[ix + j];
if (a2 > a)
{
a = a2;
ai = j;
}
}
outputActivation.Weights[i] = a;
this.switches[i] = ix + ai;
}
}
else
{
var n = 0; // counter for switches
for (var x = 0; x < input.Width; x++)
{
for (var y = 0; y < input.Height; y++)
{
for (var i = 0; i < depth; i++)
{
var ix = i * this.GroupSize;
var a = input.Get(x, y, ix);
var ai = 0;
for (var j = 1; j < this.GroupSize; j++)
{
var a2 = input.Get(x, y, ix + j);
if (a2 > a)
{
a = a2;
ai = j;
}
}
outputActivation.Set(x, y, i, a);
this.switches[n] = ix + ai;
n++;
}
}
}
}
this.OutputActivation = outputActivation;
return this.OutputActivation;
}