BOOST_CHECK_CLOSEのtolerance_srcは%!

  v=1.0;
  BOOST_CHECK_CLOSE( v, 1.3, 20.0);
  BOOST_CHECK_CLOSE( v, 1.3, 30.0);
  BOOST_CHECK_CLOSE( v, 1.3, 40.0);

test.cpp(64): error in "interpolate": difference{23.0769%} between v{1} and 1.3{1.3} exceeds 20%
test.cpp(65): error in "interpolate": difference{30%} between v{1} and 1.3{1.3} exceeds 30%