/// <summary>
/// Return a new array of given shape and type, filled with ones.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="np"></param>
/// <param name="shape"></param>
/// <returns></returns>
public NDArray ones(Shape shape, Type dtype = null)
{
if (dtype == null)
{
dtype = typeof(double);
}
var nd = new NDArray(dtype, shape);
switch (dtype.Name)
{
case "Int32":
nd.Set(Enumerable.Range(0, nd.size).Select(x => 1).ToArray());
break;
case "Double":
nd.Set(Enumerable.Range(0, nd.size).Select(x => 1.0).ToArray());
break;
case "Boolean":
nd.Set(Enumerable.Range(0, nd.size).Select(x => true).ToArray());
break;
}
return(nd);
}
/// <summary>
/// Stack arrays in sequence vertically (row wise).
/// </summary>
/// <param name="nps"></param>
/// <returns></returns>
public NDArray vstack <T>(params NDArray[] nps)
{
if (nps == null || nps.Length == 0)
{
throw new Exception("Input arrays can not be empty");
}
List <T> list = new List <T>();
var np = new NDArray(typeof(T));
foreach (NDArray ele in nps)
{
if (nps[0].shape != ele.shape)
{
throw new Exception("Arrays mush have same shapes");
}
list.AddRange(ele.Data <T>());
}
np.Set(list.ToArray());
if (nps[0].ndim == 1)
{
np.Storage.Shape = new Shape(new int[] { nps.Length, nps[0].shape.Shapes[0] });
}
else
{
int[] shapes = nps[0].shape.Shapes.ToArray();
shapes[0] *= nps.Length;
np.Storage.Shape = new Shape(shapes);
}
return(np);
}
public NDArray randint(int low, int?high = null, Shape shape = null)
{
var rng = new Random();
if (high == null)
{
high = int.MaxValue;
}
if (shape == null)
{
shape = new Shape(high.Value - low);
}
var data = new int[shape.Size];
for (int i = 0; i < data.Length; i++)
{
data[i] = rng.Next(low, high.Value);
}
var np = new NDArray(typeof(int), shape.Shapes.ToArray());
np.Set(data);
return(np);
}
public static NDArray operator /(double scalar, NDArray np1)
{
var nd = new NDArray(typeof(double), np1.shape);
switch (np1.dtype.Name)
{
case "Double":
nd.Set(np1.float64.Select(x => scalar / x).ToArray());
break;
case "Int32":
nd.Set(np1.int32.Select(x => scalar / x).ToArray());
break;
}
return(nd);
}
public static NDArray array <T>(this NumPy np, IEnumerable <T> array, int ndim = 1)
{
var nd = new NDArray(typeof(T));
nd.Set(array.ToArray());
nd.Shape = new Shape(new int[] { array.Count() });
return(nd);
}
public NDArray unique <T>()
{
var nd = new NDArray(dtype);
var data = Data <T>().Distinct().ToArray();
nd.Set(data);
nd.Storage.Shape = new Shape(data.Length);
return(nd);
}
public new matrix transpose()
{
Storage.Shape = new Shape(this.Storage.Shape.Shapes.Reverse().ToArray());
var nd = new NDArray(this.dtype, this.shape);
switch (this.dtype.Name)
{
case "Double":
nd.Set(this.float64);
break;
case "Int32":
nd.Set(this.int32);
break;
}
if (ndim == 1)
{
Storage = NDStorage.CreateByShapeAndType(dtype, new Shape(1, shape.Shapes[0]));
Storage.SetData(nd.float64);
}
else if (ndim == 2)
{
for (int idx = 0; idx < shape.Shapes[0]; idx++)
{
for (int jdx = 0; jdx < shape.Shapes[1]; jdx++)
{
this[idx, jdx] = nd[jdx, idx];
}
}
}
else
{
throw new NotImplementedException();
}
return(this);
}
public static NDArray array <T>(this NumPy np, System.Drawing.Bitmap image)
{
var imageArray = new NDArray(typeof(T));
var bmpd = image.LockBits(new System.Drawing.Rectangle(0, 0, image.Width, image.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, image.PixelFormat);
var dataSize = bmpd.Stride * bmpd.Height;
imageArray.Set(new byte[dataSize]);
System.Runtime.InteropServices.Marshal.Copy(bmpd.Scan0, (imageArray.Storage.values as byte[]), 0, imageArray.Size);
image.UnlockBits(bmpd);
imageArray.Shape = new Shape(new int[] { bmpd.Height, bmpd.Width, System.Drawing.Image.GetPixelFormatSize(image.PixelFormat) / 8 });
return(imageArray);
}
public NDArray randint(int low, int?high = null, Shape size = null)
{
var rng = new Random();
var data = new int[size.Size];
for (int i = 0; i < data.Length; i++)
{
data[i] = rng.Next(low, high.HasValue ? high.Value : int.MaxValue);
}
var np = new NDArray(typeof(int), size.Shapes.ToArray());
np.Set(data);
return(np);
}
public NDArray randint(int low, int size = 1)
{
var rng = new Random();
var data = new int[size];
for (int i = 0; i < data.Length; i++)
{
data[i] = rng.Next(low, int.MaxValue);
}
var np = new NDArray(typeof(int), size);
np.Set(data);
return(np);
}
public NDArray linspace <T>(double start, double stop, int num, bool entdpoint = true)
{
double steps = (stop - start) / ((entdpoint) ? (double)num - 1.0 : (double)num);
double[] doubleArray = new double[num];
for (int idx = 0; idx < doubleArray.Length; idx++)
{
doubleArray[idx] = start + idx * steps;
}
var nd = new NDArray(typeof(T), doubleArray.Length);
nd.Set(doubleArray);
return(nd);
}
public NDArray array <T>(T[][] data)
{
int size = data.Length * data[0].Length;
var all = new T[size];
int idx = 0;
for (int row = 0; row < data.Length; row++)
{
for (int col = 0; col < data[row].Length; col++)
{
all[idx] = data[row][col];
idx++;
}
}
var nd = new NDArray(typeof(T));
nd.Set(all.ToArray());
nd.Storage.Shape = new Shape(new int[] { data.Length, data[0].Length });
return(nd);
}