public Matrix2DFloat RandomChoice(int count)
{
if (count <= 0)
{
return(null);
}
count = Math.Min(count, Height);
var result = new Matrix2DFloat(Width, count);
var index = new List <int>();
for (var i = 0; i < Height; i++)
{
index.Add(i);
}
var random = new Random();
for (var i = 0; i < Height; i++)
{
var n = random.Next(Height);
var tmp = index[n];
index[n] = index[i];
index[i] = tmp;
}
for (var i = 0; i < count; i++)
{
var n = index[i];
for (var x = 0; x < Width; x++)
{
result[x, i] = this[x, n];
}
}
return(result);
}
public Matrix2DFloat Clone()
{
var result = new Matrix2DFloat(_Width, _Height);
_Data.CopyTo(result._Data, 0);
return(result);
}
public static Matrix2DFloat operator +(float value1, Matrix2DFloat value2)
{
var result = new Matrix2DFloat(value2.Width, value2.Height);
result.ForEach((x, y) => {
result[x, y] = value1 + value2[x, y];
});
return(result);
}
public static Matrix2DFloat operator -(Matrix2DFloat value)
{
var result = new Matrix2DFloat(value.Width, value.Height);
result.ForEach((x, y) => {
result[x, y] = -value[x, y];
});
return(result);
}
public static float Sum(Matrix2DFloat matrix)
{
float result = 0;
matrix.ForEach((x, y) => {
result = result + matrix[x, y];
});
return(result);
}
public static Matrix2DFloat operator /(Matrix2DFloat value1, float value2)
{
var result = new Matrix2DFloat(value1.Width, value1.Height);
result.ForEach((x, y) => {
result[x, y] = value1[x, y] / value2;
});
return(result);
}
public static Matrix2DFloat operator *(Matrix2DFloat value1, Matrix2DFloat value2)
{
var width = Math.Max(value1.Width, value2.Width);
var height = Math.Max(value1.Height, value2.Height);
var result = new Matrix2DFloat(width, height);
result.ForEach((x, y) => {
result[x, y] = value1[x, y] * value2[x, y];
});
return(result);
}
public Matrix2DFloat Equals(Matrix2DFloat value)
{
if (value == null)
{
return(null);
}
var result = new Matrix2DFloat(Width, Height);
result.ForEach((x, y) => {
result[x, y] = this[x, y] == value[x, y] ? 1 : 0;
});
return(result);
}
public static Matrix2DFloat operator >=(Matrix2DFloat value1, float value2)
{
if (value1 == null)
{
return(null);
}
var result = new Matrix2DFloat(value1.Width, value1.Height);
result.ForEach((x, y) => {
result[x, y] = value1[x, y] >= value2 ? 1 : 0;
});
return(result);
}
public static Matrix2DFloat operator -(Matrix2DFloat value1, Matrix2DFloat value2)
{
if (value1 == null || value2 == null)
{
return(null);
}
var width = Math.Max(value1.Width, value2.Width);
var height = Math.Max(value1.Height, value2.Height);
var result = new Matrix2DFloat(width, height);
result.ForEach((x, y) => {
result[x, y] = value1[x, y] - value2[x, y];
});
return(result);
}
public Matrix2DFloat Every(Func <float, float, float> predicate, float right)
{
int width = _Width;
int height = _Height;
var result = new Matrix2DFloat(width, height);
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
result[x, y] = predicate(this[x, y], right);
}
}
return(result);
}
public Matrix2DFloat Dot(Matrix2DFloat value)
{
if (Width != value.Height)
{
throw new ArgumentException(string.Format(
"ValueError: shapes ({0}, {1}) and ({2}, {3}) not aligned",
Width, Height,
value.Width, value.Height
));
}
var result = new Matrix2DFloat(value.Width, Height);
result.ForEach((x, y) => {
float total = 0;
int count = Width;
for (int i = 0; i < count; i++)
{
var r = this[i, y] * value[x, i];
total += r;
}
result[x, y] = total;
});
return(result);
}
