Changeset d80256d66d585a69813f277b115d039cc620e62d

Timestamp:

03/23/12 13:00:24 (15 months ago)

Author:

Raymond Toy <rtoy@…>

Children:

41f1ca3edadee2d6e00ba7dc287ea66d92897ca6

Parents:

b1ae6953934670284060ffc2810e424a5e0aac71

git-committer:

Raymond Toy <rtoy@…> (03/23/12 13:00:24)

Message:

Need to apply contagion for exp-integral-e.

Files:

• qd-gamma.lisp (modified) (1 diff)

qd-gamma.lisp

@@ -529 +529 @@
   ;;
   ;;
-  (cond ((and (realp v) (minusp v))
-         ;; E(-v, z) = z^(-v-1)*incomplete_gamma_tail(v+1,z)
-         (let ((-v (- v)))
+  (let* ((prec (float-contagion v z))
+         (v (apply-contagion v prec))
+         (z (apply-contagion z prec)))
+    (cond ((and (realp v) (minusp v))
+           ;; E(-v, z) = z^(-v-1)*incomplete_gamma_tail(v+1,z)
+           (let ((-v (- v)))
+             (* (expt z (- v 1))
+                (incomplete-gamma-tail (+ -v 1) z))))
+          ((< (abs z) 1)
+           ;; Use series for small z
+           (s-exp-integral-e v z))
+          ((>= (abs (phase z)) 3.1)
+           ;; The continued fraction doesn't converge on the negative
+           ;; real axis, and converges very slowly near the negative
+           ;; real axis, so use the incomplete-gamma-tail function in
+           ;; this region.  "Closeness" to the negative real axis is
+           ;; teken to mean that z is in a sector near the axis.
+           ;;
+           ;; E(v,z) = z^(v-1)*incomplete_gamma_tail(1-v,z)
            (* (expt z (- v 1))
-              (incomplete-gamma-tail (+ -v 1) z))))
-        ((< (abs z) 1)
-         ;; Use series for small z
-         (s-exp-integral-e v z))
-        ((>= (abs (phase z)) 3.1)
-         ;; The continued fraction doesn't converge on the negative
-         ;; real axis, and converges very slowly near the negative
-         ;; real axis, so use the incomplete-gamma-tail function in
-         ;; this region.  "Closeness" to the negative real axis is
-         ;; teken to mean that z is in a sector near the axis.
-         ;;
-         ;; E(v,z) = z^(v-1)*incomplete_gamma_tail(1-v,z)
-         (* (expt z (- v 1))
-            (incomplete-gamma-tail (- 1 v) z)))
-        (t
-         ;; Use continued fraction for everything else.
-         (cf-exp-integral-e v z))))
+              (incomplete-gamma-tail (- 1 v) z)))
+          (t
+           ;; Use continued fraction for everything else.
+           (cf-exp-integral-e v z)))))
 
 ;; Series for Fresnel S