Torture tests: what do they mean?

[jebem]

(05-15-2014 07:08 PM)DavidM Wrote:  Test 1:
(sqrt(6)^2)-6
I have a 50g, but not the Prime. So my comments are limited to that platform.

Thanks David.
I tried on the HP-Prime in CAS mode: answer: 0 (against -0.00000000002 in Home mode).
So, no news here, two different calculators in one package. Nice!

(05-15-2014 07:08 PM)DavidM Wrote:  Test 2:
(10^15 + 7.2 − 10^15) * 100
(...) First, make sure you're in Exact/CAS mode.

HP-Prime in CAS mode result: 400
HP-Prime Home mode: 0
Correct mathematical result: 720.
Here the WP-34S wins hands down. More digits means more probability to get a correct result. Not the other way around.

(05-15-2014 07:08 PM)DavidM Wrote:  Increasing the precision for non-symbolic operations would require a major architectural change for the Prime. It's certainly not impossible, but I wouldn't expect to see something like that any time soon (if ever).

Yes, that was my point.
And that is why I love that WP-34S machine even more! So cheap, little, tiny, almost empty hardware internals, lightweight pocket calculator, and yet so powerful firmware inside!

(05-15-2014 07:08 PM)DavidM Wrote:  So I guess I'm saying: I understand your frustration, but a little better understanding of how the tools are currently designed to work might give you a more acceptable (and predictable) experience. And there's nothing wrong with expecting more from the tools themselves. As consumers, we should always do that.

Totally agree. As I said, I was just pointing out that some calculators can give correct answers using the default setups for very common calculation examples.

Please see Dieter brilliant explanation above, where he points out that every single calculator have its limits, depending on how one push it.

The good number of digits to have would be infinite to handle any problem.
But let's be reasonable here, for the common situations I would say that double precision arithmetic is the least that every single scientific calculator should come with by default.

I love my HP-Prime, as much as any other calculator in my collection. They remind me of the old glorious gold age of modern computation.
But for real work I use computers. But it is me, as I make a living as a system engineer since the end of the 70's, so when I need to do some more complex calculation I just use one of my computers.