polly@leland.Stanford.EDU (polly siegel) (04/20/91)
I don't read this newsgroup, so please respond via e-mail. I am having a problem with the equation solver of my HP 28S calculator. It's been happening for quite some time, but I don't remember that it always happened. When I enter an equation, many times the variables that show up in the SOLVR menu are not the variables that I entered in my equation, and so I can't solve my equation. I have to play around with variable names until I get some that it will accept. Has anyone seen such a problem and, if so, do you know what to do about it? I've recently replaced my batteries in the hopes that that was causing the problem, but the problem is still there. Thanks for any help you can give me! Polly Siegel ------------- Stanford University (polly@grover.stanford.edu)
edp@jareth.enet.dec.com (Eric Postpischil (Always mount a scratch monkey.)) (04/22/91)
In article <1991Apr19.210456.25235@leland.Stanford.EDU>, polly@leland.Stanford.EDU (polly siegel) writes: >When I enter an equation, many times the variables that show up >in the SOLVR menu are not the variables that I entered in my equation, and >so I can't solve my equation. I have to play around with variable names until >I get some that it will accept. My guess is that the variables that aren't appearing in the menu are defined in some directory in your current path. The Solver starts with ALL the variables that appear in your equation. Then it checks each variable. If the variable is not defined or is a number, it is put in the menu. If the variable is an algebraic, then the Solver does not put that variable in the menu, but gets all the variables from that algebraic and adds them to the list it is working on. So if you have an equation '2*X=3*Y+Z' and in some directory in your current path there is an object named 'X' that is defined as 'A-B', then A, B, Y, and Z will appear in the menu. To test this, when it occurs again, do this: 'EQ' RCL HOME 'EQ' STO. Then go into the Solver. If the variables in EQ still do not appear, then look for objects with those names in the home directory and purge them. -- edp (Eric Postpischil) "Always mount a scratch monkey." edp@jareth.enet.dec.com