/// <summary>
/// Division outarray[i] / val
/// </summary>
public static void Div(Floatarray outarray, float val)
{
for (int i = 0; i < outarray.Length1d(); i++)
{
outarray.Put1d(i, outarray.At1d(i) / val);
}
}
/// <summary>
/// Subtraction val - outarray[i]
/// </summary>
public static void Sub(float val, Floatarray outarray)
{
for (int i = 0; i < outarray.Length1d(); i++)
{
outarray.Put1d(i, val - outarray.At1d(i));
}
}
/// <summary>
/// Add outarray[i] + val
/// </summary>
public static void Add(Floatarray outarray, float val)
{
for (int i = 0; i < outarray.Length1d(); i++)
{
outarray.UnsafePut1d(i, outarray.UnsafeAt1d(i) + val);
}
}
/// <summary>
/// Normalize the 1-norm of the array.
/// </summary>
public static void Normalize1(Floatarray a)
{
double scale = 1.0 / Norm1(a);
for (int i = 0; i < a.Length1d(); i++)
{
a.UnsafePut1d(i, (float)(a.UnsafeAt1d(i) * scale));
}
}
/// <summary>
/// 1-norm.
/// </summary>
public static double Norm1(Floatarray a)
{
double total = 0.0;
for (int i = 0; i < a.Length1d(); i++)
{
total += Math.Abs(a.UnsafeAt1d(i));
}
return(total);
}
public static Floatarray operator -(Floatarray array, float val)
{
Floatarray res = array;
for (int i = 0; i < array.Length1d(); i++)
{
res.UnsafePut1d(i, array.UnsafeAt1d(i) - val);
}
return(res);
}
public static Floatarray operator /(Floatarray array, double val)
{
Floatarray res = array;
for (int i = 0; i < array.Length1d(); i++)
{
res.UnsafePut1d(i, (float)(array.UnsafeAt1d(i) / val));
}
return(res);
}
/// <summary>
/// Euclidean norm squared.
/// </summary>
public static double Norm2Squared(Floatarray a)
{
double total = 0.0;
for (int i = 0; i < a.Length1d(); i++)
{
float value = a.At1d(i);
total += value * value;
}
return(total);
}
public static void Shuffle <T>(Narray <T> values)
{
Floatarray temp = new Floatarray(values.Length());
Intarray index = new Intarray();
for (int i = 0; i < temp.Length(); i++)
{
temp.UnsafePut1d(i, DRandomizer.Default.drand());
}
Quicksort(index, temp);
Permute(values, index);
}
public static float Fractile(Narray <float> a, double f)
{
Floatarray temp = new Floatarray();
if (!(f >= 0 && f <= 1))
{
throw new Exception("CHECK: f >= 0 && f <= 1");
}
temp.Copy(a);
temp.Reshape(temp.Length1d());
Quicksort(temp);
return(temp[(int)(f * temp.Length())]);
}
public static Floatarray operator -(Floatarray outarray1, Floatarray array2)
{
if (!SameDims(outarray1, array2))
{
throw new Exception("outarray1 and array2 must be same dims!");
}
Floatarray res = outarray1;
for (int i = 0; i < outarray1.Length1d(); i++)
{
res.UnsafePut1d(i, outarray1.UnsafeAt1d(i) - array2.UnsafeAt1d(i));
}
return(res);
}
public static float Max(Floatarray a)
{
float value = a.At1d(0);
for (int i = 1; i < a.Length1d(); i++)
{
float nvalue = a.At1d(i);
if (nvalue <= value)
{
continue;
}
value = nvalue;
}
return(value);
}
public Floatarray ToFloatarray()
{
Floatarray fa = new Floatarray();
fa.Resize(Width, Height);
int yput;
for (int y = 0; y < Height; y++)
{
yput = Height - y - 1;
for (int x = 0; x < Width; x++)
{
fa.Put(x, yput, Convert.ToSingle(Get(y, x) / 255.0f));
}
}
return(fa);
}
/// <summary>
/// Euclidean distance squared.
/// </summary>
public static double Dist2Squared(Floatarray a, Floatarray b)
{
if (!a.SameDims(b))
{
throw new Exception("Dist2Squared: !a.SameDims(b)");
}
double total = 0.0;
for (int i = 0; i < a.Length1d(); i++)
{
float val = a.At1d(i) - b.At1d(i);
total += val * val;
}
if (double.IsNaN(total))
{
throw new Exception("Dist2Squared: total is NaN !");
}
return(total);
}
public static int ArgMin(Floatarray a)
{
if (!(/*a.Rank() == 1 && **/ a.Dim(0) > 0))
{
throw new Exception("CHECK_ARG: a.Rank()==1 && a.Dim(0)>0");
}
float value = a.At1d(0);
int index = 0;
for (int i = 1; i < a.Length1d(); i++)
{
float nvalue = a.At1d(i);
if (nvalue >= value)
{
continue;
}
value = nvalue;
index = i;
}
return(index);
}
/// <summary>
/// Euclidean norm.
/// </summary>
public static double Norm2(Floatarray a)
{
return(Math.Sqrt(Norm2Squared(a)));
}
/// <summary>
/// Euclidean distance.
/// </summary>
public static double Dist2(Floatarray a, Floatarray b)
{
return(Math.Sqrt(Dist2Squared(a, b)));
}