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authoreb2008-05-08 06:17:55 +0000
committereb2008-05-08 06:17:55 +0000
commit593a87ce2254a7966d33fa88e2efa9cbbdb4f7f0 (patch)
treeef90d2e19a69908b0616975600bfcad30f5a50bb
parentf29ed72859a46428e1ad1d97306554b19202a958 (diff)
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better fix for ticket:243
git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@8324 221aa14e-8319-0410-a670-987f0aec2ac5
-rw-r--r--configure.ac1
-rw-r--r--gnuradio-core/src/lib/viterbi/metrics.c10
2 files changed, 11 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac
index 05c2cc050..74dde0dd1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -152,6 +152,7 @@ AC_CHECK_LIB(m, sinf, [AC_DEFINE([HAVE_SINF],[1],[Define to 1 if your system has
AC_CHECK_LIB(m, cosf, [AC_DEFINE([HAVE_COSF],[1],[Define to 1 if your system has `cosf'.])])
AC_CHECK_LIB(m, trunc, [AC_DEFINE([HAVE_TRUNC],[1],[Define to 1 if your system has `trunc'.])])
AC_CHECK_LIB(m, exp10, [AC_DEFINE([HAVE_EXP10],[1],[Define to 1 if your system has 'exp10'.])])
+AC_CHECK_LIB(m, log2, [AC_DEFINE([HAVE_LOG2],[1],[Define to 1 if your system has 'log2'.])])
#AC_FUNC_MKTIME
AH_BOTTOM([
diff --git a/gnuradio-core/src/lib/viterbi/metrics.c b/gnuradio-core/src/lib/viterbi/metrics.c
index 3351ff403..2dd4279aa 100644
--- a/gnuradio-core/src/lib/viterbi/metrics.c
+++ b/gnuradio-core/src/lib/viterbi/metrics.c
@@ -30,6 +30,10 @@
*
*/
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
/* Symbols are offset-binary, with 128 corresponding to an erased (no
* information) symbol
*/
@@ -41,6 +45,12 @@
/* Normal function integrated from -Inf to x. Range: 0-1 */
#define normal(x) (0.5 + 0.5*erf((x)/M_SQRT2))
+/* Logarithm base 2 */
+double log2(double); /* declaration seems to be missing from some math.h's */
+#if !defined(HAVE_LOG2)
+#define log2(x) (log(x)*M_LOG2E)
+#endif
+
/* Generate log-likelihood metrics for 8-bit soft quantized channel
* assuming AWGN and BPSK
*/