Add Bessel functions to SpecialFunctions.

- Split SpecialFunctions files in to a separate BesselFunctions file.

In particular add:
    - Modified bessel functions of the second kind k0, k1, k0e, k1e
    - Bessel functions of the first kind j0, j1
    - Bessel functions of the second kind y0, y1

1 files changed, 1 insertions, 41 deletions

diff --git a/unsupported/test/special_functions.cpp b/unsupported/test/special_functions.cpp
index 140a5e4c1..c104ac3c5 100644
--- a/unsupported/test/special_functions.cpp
+++ b/unsupported/test/special_functions.cpp
@@ -357,47 +357,7 @@ template<typename ArrayType> void array_special_functions()
   }
 #endif  // EIGEN_HAS_C99_MATH
 
-  // Test Bessel function i0e. Reference results obtained with SciPy.
-  {
-    ArrayType x(21);
-    ArrayType expected(21);
-    ArrayType res(21);
-
-    x << -20.0, -18.0, -16.0, -14.0, -12.0, -10.0, -8.0, -6.0, -4.0, -2.0, 0.0,
-        2.0, 4.0, 6.0, 8.0, 10.0, 12.0, 14.0, 16.0, 18.0, 20.0;
-
-    expected << 0.0897803118848, 0.0947062952128, 0.100544127361,
-        0.107615251671, 0.116426221213, 0.127833337163, 0.143431781857,
-        0.16665743264, 0.207001921224, 0.308508322554, 1.0, 0.308508322554,
-        0.207001921224, 0.16665743264, 0.143431781857, 0.127833337163,
-        0.116426221213, 0.107615251671, 0.100544127361, 0.0947062952128,
-        0.0897803118848;
-
-    CALL_SUBTEST(res = i0e(x);
-                 verify_component_wise(res, expected););
-  }
-
-  // Test Bessel function i1e. Reference results obtained with SciPy.
-  {
-    ArrayType x(21);
-    ArrayType expected(21);
-    ArrayType res(21);
-
-    x << -20.0, -18.0, -16.0, -14.0, -12.0, -10.0, -8.0, -6.0, -4.0, -2.0, 0.0,
-        2.0, 4.0, 6.0, 8.0, 10.0, 12.0, 14.0, 16.0, 18.0, 20.0;
-
-    expected << -0.0875062221833, -0.092036796872, -0.0973496147565,
-        -0.103697667463, -0.11146429929, -0.121262681384, -0.134142493293,
-        -0.152051459309, -0.178750839502, -0.215269289249, 0.0, 0.215269289249,
-        0.178750839502, 0.152051459309, 0.134142493293, 0.121262681384,
-        0.11146429929, 0.103697667463, 0.0973496147565, 0.092036796872,
-        0.0875062221833;
-
-    CALL_SUBTEST(res = i1e(x);
-                 verify_component_wise(res, expected););
-  }
-
-  /* Code to generate the data for the following two test cases.
+    /* Code to generate the data for the following two test cases.
     N = 5
     np.random.seed(3)