Curiosity about Sign[.] and Abs[.]
- To: mathgroup at smc.vnet.net
- Subject: [mg7258] Curiosity about Sign[.] and Abs[.]
- From: Michael Hucka <hucka at eecs.umich.edu>
- Date: Tue, 20 May 1997 02:58:49 -0400 (EDT)
- Organization: University of Michigan EECS, Ann Arbor, Mich., USA
- Sender: owner-wri-mathgroup at wolfram.com
I'm sure this is simply due to my cluelessness about math in general, but can someone explain to me in simple terms why the following occurs? Suppose u and v are variables, both real. In[72]:= foo = I u Sign[v] Out[72]= I u Sign[v] In[73]:= Abs[foo] Out[73]= Abs[u] What puzzles me is what happened to the value of the function foo at 0. With the signum function in there, the value of foo at v = 0 should be 0 (because Sign[0] = 0), yet this seems to disappear after taking Abs[foo]. -- Mike Hucka hucka at umich.edu http://www.eecs.umich.edu/~hucka University PhD to be, computational models of human visual processing (AI Lab) of UNIX systems administrator & programmer/analyst (EECS DCO) Michigan