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50G ABS function perplexing
Message #1 Posted by Hal Bitton in Boise on 23 Apr 2008, 12:56 a.m.

Hi folks,
The ABS (absolute value) function on my 50G is not acting as expected. When I try to apply it to an un-evaluated algebraic expression in stack level 1, I don't get the expected set of verticle brackets around the expression. If I construct the algebraic in the equation writer the ABS function works fine there, and subsequintly transitions to the stack OK. It just won't tag an expression in the stack. When I use the ABS function on a negative numerical value in level 1, the negative sign goes away as expected.

Other functions, such as IP, FP, etc., work fine in the stack (ie, brackets around the expression preceeded by the function). Is there a flag or setting I need to look at. This is rather strange.

I know I've tagged algebraics (in the stack) with the ABS function in the past, and just to be sure I'm not dreaming, I tried it on my 48GX and got the ABS tag just as expected.
Any help on this greatly appreciated.
Best regards, Hal

      
Re: 50G ABS function perplexing
Message #2 Posted by George Bailey (Bedford Falls) on 23 Apr 2008, 5:07 a.m.,
in response to message #1 by Hal Bitton in Boise

Don't know if I understand you correctly but I just tried this on my 50G in RPN mode:

'7-11'

ENTER

Left Shift-ABS

-(7-11) is displayed

Then:

'3+5'

ENTER

Left Shift-ABS

3+5 is displayed

...like I would expect.

In ALG mode I enter

Left Shift-ABS and get ABS() with the cursor between the brackets, further entering

3+5

and pressing

ENTER

yields

:|3+5|

8

with the first part on the left side and the 8 on the right side of the screen one line below. ...as expected.

Edited: 23 Apr 2008, 5:12 a.m.

            
Re: 50G ABS function perplexing
Message #3 Posted by Hal Bitton in Boise on 23 Apr 2008, 11:13 a.m.,
in response to message #2 by George Bailey (Bedford Falls)

Hi George, and thanks for your response,
Specifically, what I'm doing is trying to build the expression ABS(5*sinx) in the stack. In RPN mode my keystrokes are: 5 enter x sin * , which puts 5*sin(x) in stack level 1. I then hit left shift ABS, which should tag the expression with ABS brackets, but nothing happens. (Incedentally, accessing ABS in the MTH-REAL menu gives me the same thing...nothing)

These exact same keystrokes on the 48GX give me ABS(5*sin(x)) in stack level 1.

I don't understand why this functionality would not be present on the 50G. I would hate to have to build my expressions in the equation writer environment...it's much easier for me to build them right on the stack.
Any thoughts about this anyone?
Best regards, Hal

      
Never Mind...Figured it out
Message #4 Posted by hal bitton in boise on 23 Apr 2008, 11:44 a.m.,
in response to message #1 by Hal Bitton in Boise

It seems I didn't have "Rigorous" checked in the CAS settings, which will cause the machine to simplify ABS(x) to x.

I should have looked at the CAS setting more carefully before posting...my appologies for that.

Best regards, Hal

      
Re: 50G ABS function perplexing
Message #5 Posted by Ren on 23 Apr 2008, 1:15 p.m.,
in response to message #1 by Hal Bitton in Boise

I'd find that perplexing too...

I know HP calcs are fast,

but why would one need Anti-lock Braking System (ABS).

<grin>

Ren

dona nobis pacem

            
Re: 50G ABS function perplexing
Message #6 Posted by designnut on 23 Apr 2008, 4:05 p.m.,
in response to message #5 by Ren

I suspected one of the 256 flag settings, but I could not name it, Sam


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