intc integral along a straight path in the complex plan

## Syntax

              [y, err] = intc(a, b, f)
              [y, err] = intc(a, b, f, abserr)
              [y, err] = intc(a, b, f, abserr, relerr)

## Arguments

a, b
  two complex numbers: starting and ending points of the integral in the complex plan.

f
  Identifier of the function to be integrated.

abserr, relerr
  real scalars: absolute and relative errors. Default values: `1.d-13` and `1d-8`.

err
  real number: estimated absolute error on the result.

## Description

If `f` is a complex-valued function, `intc(a, b, f)` computes the integral from `a` to `b` of `f(z)dz` along the straight line `[a b]` of the complex plan.

## Examples

    function y = f(z)
      y = z^(3 + %pi * %i);
    endfunction

    intc(1+%i, 4-%i, f)

    [r, err] = intc(1+%i, 4-%i, f, 1d-10, 1d-6)

## See also

- intg
- intl

## History

5.5.0 Absolute and relative (input) and absolute (output) errors management added.
6.1.0 The default abserr value becomes 10-13 instead of 10-14.