From: Michael Orlitzky <michael@orlitzky.com>
Date: Thu, 4 Mar 2021 22:43:59 +0000 (-0500)
Subject: eja: improve a gram_schmidt() error message.
X-Git-Url: http://gitweb.michael.orlitzky.com/?p=sage.d.git;a=commitdiff_plain;h=8f3ba1d9473195c1cbafe967a127800d90fde3ee;hp=77f0119f043a9ceac891dc82229e550574a2a03f

eja: improve a gram_schmidt() error message.
---

diff --git a/mjo/eja/eja_utils.py b/mjo/eja/eja_utils.py
index 2402d9f..d4e9990 100644
--- a/mjo/eja/eja_utils.py
+++ b/mjo/eja/eja_utils.py
@@ -230,7 +230,14 @@ def gram_schmidt(v, inner_product=None):
     """
     if inner_product is None:
         inner_product = lambda x,y: x.inner_product(y)
-    norm = lambda x: inner_product(x,x).sqrt()
+    def norm(x):
+        ip = inner_product(x,x)
+        # Don't expand the given field; the inner-product's codomain
+        # is already correct. For example QQ(2).sqrt() returns sqrt(2)
+        # in SR, and that will give you weird errors about symbolics
+        # when what's really going wrong is that you're trying to
+        # orthonormalize in QQ.
+        return ip.parent()(ip.sqrt())
 
     v = list(v) # make a copy, don't clobber the input