Mega Code Archive
Defines a 2D Array
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#region Using Statements
using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
#endregion
namespace JigLibX.Utils
{
/// <summary>
/// Defines a 2D Array
/// </summary>
public class Array2D
{
public delegate float Function(int x, int z, Array2D arrInstance);
private int nx, nz;
private bool wrap;
public float[] Array;
public Array2D(Array2D arr)
{
if (arr == null || arr.Array == null)
return;
this.Array = new float[arr.Array.Length];
this.nx = arr.Nx;
this.nz = arr.Nz;
Buffer.BlockCopy(arr.Array, 0, this.Array, 0, this.Array.Length * 4);
}
public Array2D(int nx, int nz)
{
Array = new float[nx * nz];
this.nx = nx;
this.nz = nz;
}
public Array2D(int nx, int nz, float val)
{
Array = new float[nx * nz];
this.nx = nx;
this.nz = nz;
for (int i = 0; i < Array.Length; i++)
Array[i] = val;
}
/// <summary>
/// Creates 2D array from mathematical function
/// </summary>
/// <param name="nx"></param>
/// <param name="ny"></param>
/// <param name="yScale"></param>
/// <returns></returns>
public static Array2D CreateArray(int nx, int nz, Function func)
{
Array2D arr = new Array2D(nx, nz);
if (func == null)
return arr;
for (int xx = 0; xx < nx; xx++)
{
for (int zz = 0; zz < nz; zz++)
{
arr.Array[xx + zz * nx] = func(xx, zz, arr);
}
}
return arr;
}
/// <summary>
/// allows resizing. Data will be lost if resizing occurred
/// </summary>
/// <param name="nx"></param>
/// <param name="ny"></param>
public void Resize(int nx, int nz)
{
if (nx == this.nx && nz == this.nz)
return;
Array = new float[nx * nz];
this.nx = nx;
this.nz = nz;
}
/// <summary>
/// raise array elements to a power
/// </summary>
/// <param name="rhs"></param>
/// <returns></returns>
public Array2D Pow(float rhs)
{
for (int i = 0; i < this.nx * this.nz; ++i)
{
Array[i] = (float)System.Math.Pow(Array[i], rhs);
}
return this;
}
/// <summary>
/// sets each value to its absolute value by comparison with float(0)
/// </summary>
public void Abs()
{
for (int i = 0; i < Array.Length; ++i)
{
if (Array[i] < 0)
Array[i] = -Array[i];
}
}
/// <summary>
/// Apply a Gaussian filter with length scale r, extending over a
/// square of half-width n (so n=1 uses a square of 9 points, n = 2
/// uses 25 etc). Suggest using n at least 2*r.
/// </summary>
/// <param name="r">length scale</param>
/// <param name="n">half-width</param>
public void GaussianFilter(float r, int n)
{
int i, j, ii, jj, iii, jjj;
int size = (n * 2 + 1);
float[] filter = new float[size * size];
for (i = 0; i < size; ++i)
{
for (j = 0; j < size; ++j)
filter[i + j * size] = (float)System.Math.Exp(-((i - n) * (i - n) + (j - n) * (j - n)) / (r * r));
}
for (i = 0; i < (int)this.nx; ++i)
{
for (j = 0; j < (int)this.nz; ++j)
{
float total = 0;
float weight_total = 0;
for (ii = -n; ii < (int)n; ++ii)
{
if ((((iii = i + ii) >= 0) && (iii < this.nx)) || (wrap))
{
for (jj = -n; jj < (int)n; ++jj)
{
if ((((jjj = j + jj) >= 0) && (jjj < this.nz)) || (wrap))
{
// in a valid location
int index = (n + ii) + (n + jj) * size;
weight_total += filter[index];
total += filter[index] * GetAt(iii, jjj);
}
}
}
}
SetAt(i, j, total / weight_total);
}
}
}
/// <summary>
/// shifts all the elements...
/// </summary>
/// <param name="offsetX"></param>
/// <param name="offsetY"></param>
public void Shift(int offsetX, int offsetZ)
{
Array2D orig = new Array2D(this);
for (int i = 0; i < this.nx; ++i)
{
for (int j = 0; j < this.nz; ++j)
{
int i0 = (i + offsetX) % this.nx;
int j0 = (j + offsetZ) % this.nz;
this.SetAt(i0, j0, orig.GetAt(i, j));
}
}
}
/// <summary>
/// scale to fit within range...
/// </summary>
/// <param name="valMin"></param>
/// <param name="valMax"></param>
public void SetRange(float valMin, float valMax)
{
int i;
float origMin = this.Min;
float origMax = this.Max;
// set min to 0 and scale...
float scale = (valMax - valMin) / (origMax - origMin);
float offset = valMin - scale * origMin;
for (i = 0; i < Array.Length; ++i)
{
Array[i] = scale * Array[i] + offset;
}
}
/// <summary>
/// Set to a constant value
/// </summary>
/// <param name="val"></param>
public void SetTo(float val)
{
for (int i = 0; i < Array.Length; ++i)
{
Array[i] = val;
}
}
/// <summary>
/// checked access - unwraps if wrapping set
/// </summary>
/// <param name="i"></param>
/// <param name="j"></param>
/// <returns></returns>
public float GetAt(int i, int j)
{
UnwrapIndices(ref i, ref j);
return Array[i + j * this.nx];
}
/// <summary>
/// checked access - unwraps if wrapping set
/// </summary>
public void SetAt(int i, int j, float val)
{
UnwrapIndices(ref i, ref j);
Array[i + j * this.nx] = val;
}
private void UnwrapIndices(ref int i, ref int j)
{
if (wrap == false)
return;
while (i < 0)
i += this.nx;
while (j < 0)
j += this.nz;
i = i % this.nx;
j = j % this.nz;
}
/// <summary>
/// ! Unchecked access - no wrapping
/// </summary>
/// <param name="i"></param>
/// <param name="j"></param>
/// <returns></returns>
public float this[int i, int j]
{
get
{
return Array[i + j * this.nx];
}
}
/// <summary>
/// enables/disables wrapping
/// </summary>
public bool Wrap
{
get { return wrap; }
set { wrap = value; }
}
/// <summary>
/// Gets the 'x' size of the array
/// </summary>
public int Nx
{
get { return this.nx; }
}
/// <summary>
/// Gets the 'y' size of the array
/// </summary>
public int Nz
{
get { return this.nz; }
}
public float Min
{
get
{
float min = Array[0];
for (int i = 0; i < Array.Length; ++i)
{
if (Array[i] < min)
min = Array[i];
}
return min;
}
}
public float Max
{
get
{
float max = Array[0];
for (int i = 0; i < Array.Length; ++i)
{
if (max < Array[i])
max = Array[i];
}
return max;
}
}
}
}
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