|Re: A 12CP bug? |
Message #5 Posted by Gerson W. Barbosa on 24 July 2006, 11:33 a.m.,
in response to message #4 by Gene Wright
In fact, I can't remember ever seeing a sequence like 2 ENTER CHS 3 x in a program before. :-)
Actually I did not observe this in a program. I was testing my trigs program below with negative arguments as I just had made a change so as ACOS worked in the range [-1..0]. ASIN and ACOS were ok but when I cheked ATAN I obtained wrong results. At first I thought it was a bug in my own program. However this had not shown up in an equivalent program I had written for the HP-15C. Besides I had made no changes in the ATAN routine. It took a while to find the problem. Fortunately, it was just another 12CP bug...
Do I apply for a replacement when they fix that or perhaps they just don't consider this a bug anyway? :-)
This is what I was testing:
In this case, the best sequence would be:
1 EEX 7 1. 07
g GTO 102 R/S 89.99999427 This was supposed to return atan(-10,000,000).
The calculator returns atan(10,000,000) instead.
1 CHS EEX -1. 00
7 -1. 07
g GTO 102 R/S -89.99999427 Ok!
This requires one keystroke less and returns the right result. But the first method should be expected to work because the calculator is actually displaying a negative number just before running the program.