[BUG (Emulator)] Emulator eats CPU when in Advanced Graphing Plot view

[Stefan]

Note: I'm running the emulator in Wine (Crossover to be specific). So maybe this doesn't occur under Windows.

Bug description:
Open the Advanced Graphing App, enter an expression to plot in symbolic view (e.g. Y^2+X^2<=1)
Switch to Plot view.

Result:
HP Prime emulator uses one complete CPU core, Fan is turning crazy :-)
Note: Although the CPU core is loaded 100%, the emulator doesn't get unresponsive.

@jebem: See, now I'm reporting on bugs in the emulator :-)

[eried]

I think that's not a bug, advanced graphing is an iterative solver (in every iteration it adds more details) and it probably never goes to idle by design.

[Stefan]

If this is indeed the problem, it would be a good idea to stop calculation as soon as the evaluation area becomes smaller than what 1 pixel can display.
But on the other hand I can't really imagine that they wouldn't have thought about this.

[eried]

The trace tool does not "trace" per pixel. Also it seems the routine is drawing small contiguous areas (check by scrolling very little to the sides).

But thinking on your CPU observation, I am guessing this might be the thing wasting the battery on *some special* occasions, so it might seem a good idea to limit these threads. Besides, the http://www.peda.com/products/ copyright spamming in the Prime looks uncool :/

[jte]

(03-15-2014 06:56 PM)eried Wrote:  ...Besides, the http://www.peda.com/products/ copyright spamming in the Prime looks uncool :/

Cool or not, this was what ended up being agreed upon. Other possibilities were considered (such as giving credit in the boot logo). It's hard to see a copyright notice as spamming (the HP logo is shown all the time).

[jte]

(03-15-2014 06:26 PM)Stefan Wrote:  If this is indeed the problem, it would be a good idea to stop calculation as soon as the evaluation area becomes smaller than what 1 pixel can display.
But on the other hand I can't really imagine that they wouldn't have thought about this.

This is something that should be addressed in internal development builds in the near future. As Tim has mentioned, when or whether or not such changes come out in updates will only be known when announced (or distributed) by HP officially.

This is a much bigger issue for the emulator than it is for the calculator.

[Stefan]

(03-15-2014 06:56 PM)eried Wrote:  Besides, the http://www.peda.com/products/ copyright spamming in the Prime looks uncool :/

Its a cool feature of the prime (after all its one of the few "App" one doesn't have to be ashamed of for its placement in the Appmenu). So why not give credit to them in this rather unobstrusive way when it wasnt developed by HP?

[Tim Wessman]

The little blurb comes up once per boot. The emulator will do this every time you open the calculator, but on the device it is actually quite rare. The author of most of the graphing apps also has posted a few times on this forum but has remained anonymous so far.

I believe the last release didn't have the code that stopped the graphing once it hit certain levels, but I can say this was a known issue that was not meant to remain long term.

[eried]

(03-15-2014 07:38 PM)Stefan Wrote:  Its a cool feature of the prime (after all its one of the few "App" one doesn't have to be ashamed of for its placement in the Appmenu). So why not give credit to them in this rather unobstrusive way when it wasnt developed by HP?

I am not against giving credit to developers, they certainly deserve it, but I would prefer that info added to a proper section, not as a 'splash' label.

For just one reason: the objective public of that label is probably the people that notice the label (it might be invisible for mainstream users), so it is just bugging the wrong (obsessive?) people. But I agree that it is a dumb 'fix' and there are more critical things to --bla blah.

[jebem]

(03-15-2014 02:57 PM)Stefan Wrote:  Note: I'm running the emulator in Wine (Crossover to be specific). So maybe this doesn't occur under Windows.

Bug description:
Open the Advanced Graphing App, enter an expression to plot in symbolic view (e.g. Y^2+X^2<=1)
Switch to Plot view.

Result:
HP Prime emulator uses one complete CPU core, Fan is turning crazy :-)
Note: Although the CPU core is loaded 100%, the emulator doesn't get unresponsive.

@jebem: See, now I'm reporting on bugs in the emulator :-)

Hi, Stefan, thanks for reporting more "issues" here... it is good for HP as well, so they have good people testing and reporting abnormal conditions that someone in charge may be able to get fixed one of these days.
I was in Angola and only now have the chance to pay attention to our HP Prime posts.

I have duplicated this "issue" by running the HP Prime calculator program on two different Windows 7 computers:
- One Intel 7 dual core with hyper-threading (4 logical cores) Processor will consume about 40% CPU (Core 0 goes to 99%, Core 2 goes to about 80%).
- Another AMD Phenom II X6 (6 physical cores) Processor will consume about 30% CPU (Core 3 goes to about 99%, Core 4 goes to about 80%).

So the behavior is similar on both computers - the calculator program will take 2 Cores while the plotting is running, and it stays there even when we see no visual activity in the graph.

However, the good news is that the CPU utilization goes to zero as soon as we press the Home key.