Trapezoidal numerical integration.

  Z = TRAPZ(X,Y) computes the integral of Y with respect to X using

  trapezoidal integration.  X and Y must be vectors of the same length,

  or X must be a column vector and Y a matrix with as many rows as X.

  TRAPZ computes the integral of each column of Y separately.

  The resulting Z is a scalar or a row vector.



  Z = TRAPZ(Y) computes the trapezoidal integral of Y assuming unit

  spacing between the data points.  To compute the integral for

  spacing different from one, multiply Z by the spacing increment.



  See also SUMN26LU2, CUMSUMKIA13Y.