2Dlineintegral

代码说明：

  PIECEWISE_EVAL: evaluates a piecewise function of x usage: y = PIECEWISE_EVAL(x,breakpoints,funs) arguments (input) x - vector or array of points to evaluate though the function breakpoints - list of n breakpoints, -inf and +inf are implicitly(PIECEWISE_EVAL : evaluates a piecewise function of x usage : PIECEWISE_EVAL y = (x, breakpoints, funs) arguments (input) x-vector or array of po ints to evaluate the function though breakpoin ts-list of n breakpoints.- inf and inf are implicitly)