combinations of pure functions
- To: mathgroup at smc.vnet.net
- Subject: [mg16532] combinations of pure functions
- From: Gianluca Gorni <gorni at dimi.uniud.it>
- Date: Tue, 16 Mar 1999 04:00:09 -0500
- Sender: owner-wri-mathgroup at wolfram.com
Hello!
Talking of operators, consider the example of the Book
at Section 2.2.9:
op = Identity + (D[#,x]&)
To find the value of op on the expression x^2 it is
suggested to use Through:
Through[op[x^2], Plus]
Unfortunately the suggestion fails if we just change +
into - in op:
op2 = Identity - (D[#,x]&)
What can one do? I have thought of a replacement rule:
op2 /. {Identity -> x^2, f_Function -> f[x^2] }
Anyone has a better idea?
Thank you in advance,
Gianluca Gorni
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| Gianluca Gorni |
| Universita` di Udine |
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