Global functions

• array merge( iarray mask, array a, array b )

  return an array (or iarray) r such that where mask[i]==1, r[i]=a[i], otherwise r[i]=b[i].

• array pack( array x, iarray mask, [int ntrue])

  Construct a new array from elements of x that correspond to where the mask is true. ntrue is an optional parameter equal to the number of true elements of mask. If not given, then pack will count the true elements of mask. Give this parameter if you are using the same mask in multiple pack statements.

• iarray enumerate(iarray mask)

  Return the running sum of mask.

• iarray pcoord( int size)

  return [0..size-1]

• iarray gen_index(iarray x)

  generate a list of index values, with each number appearing in the list according to the value passed in its position. For example, if x={0,0,1,2,0,1} then the output from this function will be {3,4,4,6}

• void lgspread( array& a, array s )

  Perform lognormal variation of the components of a, with standard error given by s, ie
  

  
  
  where is normal random variate.

• void gspread( array& a, array s )

  Perform normal variation of the components of a, with standard error given by s, ie
  

  
  
  where is normal random variate.