/// <summary>
/// Generates an NdArray with all elements set to a random value
/// </summary>
/// <param name="shape">The shape of the generated array</param>
/// <returns>An NdArray with all elements set to a random value</returns>
public virtual NdArray <T> Random(Shape shape)
{
var x = new NdArray <T>(shape);
UFunc.Apply <T, TRand>(new TRand(), x);
return(x);
}
/// <summary>
/// Repeats elements of the array
/// </summary>
/// <param name="repeats">The number of repeats to perform</param>
/// <param name="axis">The axis to repeat, if not speficied, repeat is done on a flattened array</param>
/// <returns>A repeated copy of the input data</returns>
public NdArray <T> Repeat(long repeats, long?axis = null)
{
long real_axis =
axis.HasValue ?
(axis.Value < 0 ? this.Shape.Dimensions.LongLength - (axis.Value + 1) : (axis.Value + 1))
: this.Shape.Dimensions.LongLength;
//First we add a new axis so all elements are in their own dimension
var lv = this.Subview(Range.NewAxis, real_axis);
//Then we extend the element dimension, and make the shapes match
long[] targetDims = lv.Shape.Dimensions.Select(x => x.Length).ToArray();
targetDims[real_axis] = repeats;
var tp = Shape.ToBroadcastShapes(lv.Shape, new Shape(targetDims));
//And then we can just copy data as normal
var res = UFunc.Apply <T, CopyOp <T> >(lv.Reshape(tp.Item1), new NdArray <T>(tp.Item2));
//With no axis specified, we return a flat view
if (!axis.HasValue)
{
return(new NdArray <T>(res.m_data));
}
else
{
//With a specified axis, we return a reshaped array
long[] newDims = this.Shape.Dimensions.Select(x => x.Length).ToArray();
newDims[real_axis - 1] = repeats * newDims[real_axis - 1];
return(res.Reshape(newDims));
}
}
/// <summary>
/// Sets all elements in the view to a specific value
/// </summary>
/// <param name="value">The value to set the elements to</param>
public void Set(T value)
{
var tmp = new NdArray <T>(value);
tmp = tmp.Reshape(Shape.ToBroadcastShapes(tmp.Shape, this.Shape).Item1);
UFunc.Apply <T, CopyOp <T> >(tmp, this);
}
/// <summary>
/// Generates an NdArray with sequential integers, starting with zero
/// </summary>
/// <param name="shape">The shape of the generated array</param>
/// <returns>A shaped NdArray with sequential integers, starting with zero</returns>
public NdArray <T> Range(Shape shape)
{
var x = new NdArray <T>(shape);
UFunc.Apply <T, TRange>(new TRange(), x);
return(x);
}
/// <summary>
/// Generates an NdArray with all elements set to a random value
/// </summary>
/// <param name="size">The length of the generated array</param>
/// <returns>An NdArray with all elements set to a random value</returns>
public virtual NdArray <T> Random(long size)
{
var x = new NdArray <T>(new Shape(size));
UFunc.Apply <T, TRand>(new TRand(), x);
return(x);
}
/// <summary>
/// Generates an NdArray with sequential integers, starting with zero
/// </summary>
/// <param name="size">The length of the generated array</param>
/// <returns>An NdArray with sequential integers, starting with zero</returns>
public NdArray <T> Range(long size)
{
var x = new NdArray <T>(new Shape(size));
UFunc.Apply <T, TRange>(new TRange(), x);
return(x);
}
/// <summary>
/// Gets a subview on the array, collapses all single dimensions
/// </summary>
/// <param name="ranges">The range get the view from</param>
/// <returns>A view on the selected element</returns>
public NdArray <T> this[params Range[] ranges]
{
get
{
return(this.Subview(ranges, true));
}
set
{
NdArray <T> lv = this[ranges];
var broadcastShapes = Shape.ToBroadcastShapes(value.Shape, lv.Shape);
UFunc.Apply <T, NumCIL.CopyOp <T> >(value.Reshape(broadcastShapes.Item1), lv.Reshape(broadcastShapes.Item2));
}
}
/// <summary>
/// Returns a transposed view of this array. If <paramref name="out"/> is supplied, the contents are copied into that array.
/// </summary>
/// <param name="out">Optional output array</param>
/// <returns>A transposed view or copy</returns>
public NdArray <T> Transpose(NdArray <T> @out = null)
{
if (this.Shape.Dimensions.LongLength == 1)
{
return(new NdArray <T>(this));
}
//Optimal case, just reshape the array
if (@out == null)
{
return(this.Reshape(new Shape(this.Shape.Dimensions.Reverse().ToArray())));
}
var lv = this.Reshape(new Shape(this.Shape.Dimensions.Select(x => x.Length).Reverse().ToArray()));
UFunc.Apply <T, CopyOp <T> >(lv, @out);
return(@out);
}
/// <summary>
/// Gets a subview on the array
/// </summary>
/// <param name="index">The element to get the view from</param>
/// <returns>A view on the selected element</returns>
public NdArray <T> this[params long[] index]
{
get
{
NdArray <T> v = this;
foreach (long n in index)
{
v = v.Subview(n);
}
return(v);
}
set
{
NdArray <T> lv = this[index];
//Self-assignment
if (lv.Shape.Equals(value.Shape) && value.m_data == this.m_data)
{
return;
}
if (lv.Shape.Dimensions.Length != value.Shape.Dimensions.Length)
{
throw new Exception("Cannot assign incompatible arrays");
}
for (long i = 0; i < lv.Shape.Dimensions.Length; i++)
{
if (lv.Shape.Dimensions[i].Length != value.Shape.Dimensions[i].Length)
{
throw new Exception("Cannot assign incompatible arrays");
}
}
UFunc.Apply <T, NumCIL.CopyOp <T> >(value, lv);
}
}
/// <summary>
/// Concatenates multiple arrays into a single array, joined at the axis
/// </summary>
/// <param name="axis">The axis to join at</param>
/// <param name="args">The arrays to join</param>
/// <returns>The joined array</returns>
public static NdArray <T> Concatenate(NdArray <T>[] args, long axis = 0)
{
if (args == null)
{
throw new ArgumentNullException("args");
}
if (args.LongLength == 1)
{
return(args[0]);
}
Shape basicShape = args[0].Shape.Plain;
NdArray <T>[] ext = new NdArray <T> [args.LongLength];
foreach (var a in args)
{
if (a.Shape.Elements != 1)
{
basicShape = a.Shape.Plain;
break;
}
}
for (long i = 0; i < args.LongLength; i++)
{
var lv = args[i];
while (lv.Shape.Dimensions.LongLength <= axis)
{
lv = lv.Subview(Range.NewAxis, 0);
}
ext[i] = lv;
}
long newAxisSize = 0;
foreach (var a in ext)
{
newAxisSize += a.Shape.Dimensions[axis].Length;
}
long[] dims = basicShape.Plain.Dimensions.Select(x => x.Length).ToArray();
dims[Math.Min(axis, dims.LongLength - 1)] = newAxisSize;
var res = new NdArray <T>(new Shape(dims));
var reslv = res;
while (reslv.Shape.Dimensions.LongLength <= axis)
{
reslv = reslv.Subview(Range.NewAxis, 0);
}
foreach (var a in ext)
{
if (a.Shape.Dimensions.LongLength != reslv.Shape.Dimensions.LongLength)
{
throw new Exception(string.Format("Incompatible shapes, size {0} vs {1}", a.Shape.Dimensions.LongLength, reslv.Shape.Dimensions.LongLength));
}
for (long i = 0; i < dims.LongLength; i++)
{
if (i != axis && reslv.Shape.Dimensions[i].Length != a.Shape.Dimensions[i].Length)
{
throw new Exception(string.Format("Incompatible shapes, sizes in dimension {0} is {1} vs {2}", i, a.Shape.Dimensions[i].Length, reslv.Shape.Dimensions[i].Length));
}
}
}
long startOffset = 0;
foreach (NdArray <T> a in ext)
{
long endOffset = startOffset + a.Shape.Dimensions[axis].Length;
var lv = reslv.Subview(new Range(startOffset, endOffset), axis);
UFunc.Apply <T, CopyOp <T> >(a, lv);
startOffset = endOffset;
}
return(res);
}
/// <summary>
/// Repeats elements of the array
/// </summary>
/// <param name="repeats">The number of repeats to perform in each axis</param>
/// <param name="axis">The axis to repeat, if not specified, repeat is done on a flattened array</param>
/// <returns>A repeated copy of the input data</returns>
public NdArray <T> Repeat(long[] repeats, long?axis = null)
{
long real_axis =
axis.HasValue ?
(axis.Value < 0 ? this.Shape.Dimensions.LongLength - axis.Value : axis.Value)
: this.Shape.Dimensions.LongLength;
if (!axis.HasValue)
{
//Inefficient because we need to access each element
long elements = this.Shape.Elements;
if (elements % repeats.LongLength != 0)
{
throw new ArgumentException(string.Format("The repeats array has length {0} and is not broadcast-able to length {1}", repeats.LongLength, elements), "repeats");
}
//We need to be able to address each element individually,
// so we do not use tricks stride tricks and
// just copy each element individually
long resultSize = 0;
for (long i = 0; i < elements; i++)
{
resultSize += repeats[i % repeats.LongLength];
}
T[] result = new T[resultSize];
long[] counters = new long[this.Shape.Dimensions.LongLength];
long[] limits = this.Shape.Dimensions.Select(x => x.Length).ToArray();
var va = this.Value;
long resCount = 0;
//The we remove all the outer axis definitions, but preserve the stride for each element
for (long i = 0; i < elements; i++)
{
T value = va[counters];
for (long j = 0; j < repeats[i % repeats.LongLength]; j++)
{
result[resCount++] = value;
}
//Basically a ripple carry adder
long p = counters.LongLength - 1;
while (++counters[p] == limits[p] && p > 0)
{
counters[p] = 0;
p--;
}
}
return(new NdArray <T>(result));
}
else
{
if (this.Shape.Dimensions[real_axis].Length % repeats.LongLength != 0)
{
throw new ArgumentException(string.Format("The repeats array has length {0} and is not broadcast-able to length {1}", repeats.LongLength, this.Shape.Dimensions[real_axis].Length), "repeats");
}
long resultSize = 1;
if (repeats.LongLength != this.Shape.Dimensions[real_axis].Length)
{
long[] tmp = new long[this.Shape.Dimensions[real_axis].Length];
for (long i = 0; i < tmp.LongLength; i++)
{
tmp[i] = repeats[i % repeats.LongLength];
}
repeats = tmp;
}
long extendedSize = repeats.Aggregate((a, b) => a + b);
for (long i = 0; i < this.Shape.Dimensions.LongLength; i++)
{
if (i == real_axis)
{
resultSize *= extendedSize;
}
else
{
resultSize *= this.Shape.Dimensions[i].Length;
}
}
long[] resultDims = this.Shape.Dimensions.Select(x => x.Length).ToArray();
resultDims[real_axis] = extendedSize;
var resultShape = new Shape(resultDims);
var result = new NdArray <T>(resultShape);
long curStart = 0;
for (long i = 0; i < repeats.LongLength; i++)
{
var lv = this.Subview(Range.El(i), real_axis);
var xv = result.Subview(new Range(curStart, curStart + repeats[i]), real_axis);
var broadcastShapes = Shape.ToBroadcastShapes(lv.Shape, xv.Shape);
UFunc.Apply <T, CopyOp <T> >(lv.Reshape(broadcastShapes.Item1), xv.Reshape(broadcastShapes.Item2));
curStart += repeats[i];
}
return(result);
}
}
/// <summary>
/// Returns a copy of the underlying data, shaped as this view
/// </summary>
/// <returns>A copy of the view data</returns>
public NdArray <T> Clone()
{
return(UFunc.Apply <T, CopyOp <T> >(this));
}
/// <summary>
/// Sets the values in this view to values from another view, i.e. copies data
/// </summary>
/// <param name="value">The data to assign to this view</param>
public void Set(NdArray <T> value)
{
var broadcastShapes = Shape.ToBroadcastShapes(value.Shape, this.Shape);
UFunc.Apply <T, NumCIL.CopyOp <T> >(value.Reshape(broadcastShapes.Item1), this.Reshape(broadcastShapes.Item2));
}
