TSP (libtsp) - MAfTpQuad

MAfTpQuad

Routine

double MAfTpQuad (const float R[], const float x[], int N)

Purpose

Calculate a quadratic form for a symmetric Toeplitz matrix

Description

This routine calculates a quadratic form S = x'R x, where x is a vector and R is a symmetric Toeplitz matrix,

      N-1 N-1
  S = SUM SUM x(i) R(i,j) x(j) .
      i=0 j=0

The elements of the matrix R are constant down diagonals, R(i,j) = R(|i-h|). In this routine R is specified by its first column or row. The result is accumulated as a double value and returned as a double value.

Parameters

<- double MAfTpQuad: Resultant value
-> const float R[]: First column (or row) of the symmetric Toeplitz matrix (N values)
-> const float x[]: Vector of N values
-> int N: Number of elements in x and R

Author / revision