From 8916b8b2f24b374dfda8a9dd37e6b8d6bf7602c4 Mon Sep 17 00:00:00 2001
From: Richard Kreckel <Richard.Kreckel@uni-mainz.de>
Date: Mon, 20 Dec 1999 22:12:02 +0000
Subject: [PATCH] - added a abs() function. haven't you been longing for this?

---
 ginac/inifcns.cpp | 23 +++++++++++++++++++++++
 ginac/inifcns.h   |  3 +++
 2 files changed, 26 insertions(+)

diff --git a/ginac/inifcns.cpp b/ginac/inifcns.cpp
index 28cadfb1..dc13eb29 100644
--- a/ginac/inifcns.cpp
+++ b/ginac/inifcns.cpp
@@ -41,6 +41,29 @@
 namespace GiNaC {
 #endif // ndef NO_GINAC_NAMESPACE
 
+//////////
+// absolute value
+//////////
+
+static ex abs_evalf(ex const & x)
+{
+    BEGIN_TYPECHECK
+        TYPECHECK(x,numeric)
+    END_TYPECHECK(abs(x))
+    
+    return abs(ex_to_numeric(x));
+}
+
+static ex abs_eval(ex const & x)
+{
+    if (is_ex_exactly_of_type(x, numeric))
+        return abs(ex_to_numeric(x));
+    else
+        return abs(x).hold();
+}
+
+REGISTER_FUNCTION(abs, abs_eval, abs_evalf, NULL, NULL);
+
 //////////
 // dilogarithm
 //////////
diff --git a/ginac/inifcns.h b/ginac/inifcns.h
index fdd33108..6f5f4722 100644
--- a/ginac/inifcns.h
+++ b/ginac/inifcns.h
@@ -30,6 +30,9 @@
 namespace GiNaC {
 #endif // ndef NO_GINAC_NAMESPACE
 
+/** Absolute value. */
+DECLARE_FUNCTION_1P(abs)
+
 /** Sine. */
 DECLARE_FUNCTION_1P(sin)
 
-- 
2.44.0