From: Alexei Sheplyakov <Alexei.Sheplyakov@gmail.com>
Date: Sat, 18 Jan 2014 12:13:46 +0000 (+0200)
Subject: log_eval: don't apply the log(x^p) -> p*log(x) rule.
X-Git-Tag: release_1-6-3~24
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=bee5f67dae5b409bc53ff71cb98f6630832540e7

log_eval: don't apply the log(x^p) -> p*log(x) rule.

Automatically transforming log(p^2) into 2 log(p) might be quite annoying.
Perhaps this transformation should be moved to expand() and applied only
if expand_options::expand_transcendental is specified.
---

diff --git a/check/exam_inifcns.cpp b/check/exam_inifcns.cpp
index 32368e60..3a1a36b5 100644
--- a/check/exam_inifcns.cpp
+++ b/check/exam_inifcns.cpp
@@ -310,9 +310,6 @@ static unsigned inifcns_consist_log()
 	if (!e1.is_equal(e2))
 		++result;
 
-	if (!ex(log(pow(p,a))).is_equal(a*log(p)))
-		++result;
-
 	// shall not do for non-real powers
 	if (ex(log(pow(p,z))).is_equal(z*log(p)))
 		++result;
diff --git a/ginac/inifcns_trans.cpp b/ginac/inifcns_trans.cpp
index 56d909c6..c5551f75 100644
--- a/ginac/inifcns_trans.cpp
+++ b/ginac/inifcns_trans.cpp
@@ -175,11 +175,6 @@ static ex log_eval(const ex & x)
 			return t;
 	}
 
-	// log(p^a) -> a*log(p), if p>0 and a is real
-	if (is_exactly_a<power>(x) && x.op(0).info(info_flags::positive) && x.op(1).info(info_flags::real)) {
-		return x.op(1)*log(x.op(0));
-	}
-
 	return log(x).hold();
 }