[chuck-users] Remove duplicates from array

21 Apr 2006

      Hello everyone,

I tried to send this earlier today, and it didn't seem to come through, but
in the meantime I did more work on the problem.

I am writing some functions that will be made into a class, for doing basic
serial operations on cells (i.e. arrays of floats). The operations I have so
far are: transpose, reverse, invert, permute, shuffle.

The next function to finish is multiply, which does Boulez-style cell
multiplication. For the function to work correctly, it should remove any
duplicates from the array. Unfortunately, my brain's a little rusty right
now. I'm sure I did this in the only computer class I ever took (C++). But
I'm too sleepy to figure out the correct solution offhand, I think the ways
I'm coming up with are inefficient. Can anyone help? My attempt at this is
in the function remDup below, but I made some mistake, I'm sure relating to
using a while loop--I'm not sure what the problem is though, or a better way
to do it.

I've gotten really spoiled, by usually coding these sorts of things in
Python, where its amazingly quick to do list manipulations of any kind.

//cellFun.ck

public class Argh
{
  fun static void print(float cell[])
  {
    for (0 => int i; i>> ;
    }
  }

  fun static void remove (float a[], int index)
  {
    a.cap()-1 => int newLength;
    float temp[newLength];
    for (0 => int i; i < newLength; i++)
    {
      if (i temp[i];
      }
      else
      {
        a[i+1] => temp[i];
      }
    }
    float a[newLength];
    for (0 => int i; i < newLength; i++ )
    {
      temp[i] => a[i];
    }
  }

  //match
  fun static int match(float cell[], float element)
  {
    cell.cap() => int length;
    -1 => int position;
    for (0 => int i; i position;
        break;
      }
    }
    return position;
  }

  fun static float[] copy(float cell[])
  {
    cell.cap() => int length;
    float newCell[length];
    for (0 => int i; i newCell[i];
    }
    return (newCell);
  }

  //sort
  fun static float[] sort(float cell[])
  {
  cell.cap() => int length;
  float temp;
  for (0 => int x ; x < length-1; x++)
    {
    for (0 => int y; y < length-x-1; y++)
      {
          if (cell[y] > cell[y+1])
          {
              cell[y] => temp;
              cell[y+1] => cell[y];
              temp => cell[y+1];
          }
      }
    }
  return cell;
  }

  fun static float[] remDup(float cell[])
  {
  1 => int i;
  cell.cap() => int length;
  while (i < length-1)
  {
    if (cell[i]==cell[i+1])
    {
      remove(cell,i+1);
    }
    else
    {
      i++;
    }
  }
  return cell;
  }

}

[chuck-users] Remove duplicates from array

David Powers