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subs_expr with e^t

asked 2012-01-01 17:13:51 -0600

Mike Witt gravatar image

updated 2015-01-14 07:15:36 -0600

FrédéricC gravatar image

Is there a reason why subs_expr() won't work here?

sage: version()
'Sage Version 4.7.2, Release Date: 2011-10-29'
sage: t = var('t')
sage: foo = e^t
sage: foo.subs_expr(e==e.n())
e^t
sage:
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answered 2012-01-02 01:55:29 -0600

Use a wild card (a variable that matches everything) to do complicated subs_expr. I would suggest this technique to be written in sage tutorials. It is very useful to me.

sage: t = var('t')
sage: foo = e^t
sage: w0 = SR.wild(0)
sage: foo.subs_expr(e^w0==e.n()^w0)
2.71828182845905^t
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Comments

1

You are right about this. There are a few places it shows up if you search for things but it's not there. Why not open a ticket and post a patch to the doc for this? Thanks!

kcrisman gravatar imagekcrisman ( 2012-01-02 04:26:53 -0600 )edit

Great. This worked for me, in the much more complicated expression I was actually using (which incidentally would not plot without doing this conversion first). Thanks!

Mike Witt gravatar imageMike Witt ( 2012-01-02 04:58:47 -0600 )edit
1

@kcrisman : Thanks for the suggestion. I will try to make a patch to the doc.

tririver gravatar imagetririver ( 2012-01-02 06:15:59 -0600 )edit

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Asked: 2012-01-01 17:13:51 -0600

Seen: 127 times

Last updated: Jan 02 '12