CoCoA Project

21 Dec 2019

17:22 CoCoALib Bug #1376: GBasisTimeout: not working as expected

I have just spent quite a while trying to work out where I could insert a time-out check inside the reduction code.
... John Abbott

20 Dec 2019

17:10 CoCoALib Design #1378 (New): Create two separate radical fns (for 0-dim ideals)

Proposal: create two functions for computing radicals
* *@radical@* which also tries hard to compute a GB for the r... John Abbott

17:05 CoCoALib Slug #1375: Radical 0-dim: varied timings

I propose doing an experiment along the following lines.
We create a collection of test ideals (perhaps as many a... John Abbott

16:59 CoCoALib Design #1377: CpuTimeLimit: limit "intervals" between full checks

I have checked in the code (even though it is not quite finished yet). It worked tolerably well in my two tests.
John Abbott

16:34 CoCoALib Design #1377: CpuTimeLimit: limit "intervals" between full checks

I have an improved impl, which I hope to check in fairly soon (later today?).
A problem with the description in co... John Abbott

16:58 CoCoALib Bug #1376: GBasisTimeout: not working as expected

The main problem with checking for timeout during GB computation is that the times for each single reduction can vary... John Abbott

17 Dec 2019

12:25 CoCoA-5 Bug #1093 (In Progress): GUI: bugs and slugs

I have changed *@configure@* so that it sets a flag saying whether to build the Qt GUI; this is determined by a comma... John Abbott

16 Dec 2019

21:31 CoCoA-5 Bug #1093: GUI: bugs and slugs

Ulrich reported that the GUI fails to compile now that we are using *@nullptr@*.
I had a quick search online, and fo... John Abbott

14 Dec 2019

12:37 CoCoALib Design #1377: CpuTimeLimit: limit "intervals" between full checks

Now I'm thinking it may be simpler to use an approach like this:
measure actual @CpuTime@ difference over the last... John Abbott

12:32 CoCoALib Bug #1376: GBasisTimeout: not working as expected

Reply to comment 6:
yes, @CpuTimeLimit@ does already attempt to adapt automatically. I'm discussing (with myself?) ... John Abbott

13 Dec 2019

18:17 CoCoALib Design #1377 (In Progress): CpuTimeLimit: limit "intervals" between full checks

The experimental results above suggest that approach *(B)* is probably too simplistic if there is any risk of a @CpuT... John Abbott

14:33 CoCoALib Design #1377: CpuTimeLimit: limit "intervals" between full checks

Here are the results of an extreme speed test for option *(B)* in the previous comment.
The simplistic test progra... John Abbott

13:46 CoCoALib Design #1377: CpuTimeLimit: limit "intervals" between full checks

My current suggestions:
* *(A)* let the creator of the @CpuTimeLimit@ object specify a maximum interval between genu... John Abbott

13:39 CoCoALib Design #1377: CpuTimeLimit: limit "intervals" between full checks

In the current CVS version, intervals between genuine checks can be as long as 1000000 calls.
*Quick reminder*: is... John Abbott

13:30 CoCoALib Design #1377 (Closed): CpuTimeLimit: limit "intervals" between full checks

A *@CpuTimeLimit@* object actually genuinely checks the time limit only every @N@ calls to the check function. The v... John Abbott

12:45 CoCoALib Bug #1376: GBasisTimeout: not working as expected

An important point to note is that the design of @CpuTimeLimit@ works best when the times between successive calls to... John Abbott

12 Dec 2019

21:44 CoCoALib Bug #1376 (In Progress): GBasisTimeout: not working as expected

It seems that my guess was good.
In @CpuTimeLimit.C@ around line 67, the code allowed the interval between full ch... John Abbott

17:04 CoCoALib Bug #1376: GBasisTimeout: not working as expected

I noticed the problem while using a simple program to look for ideals where it was costly to compute the RGB of the r... John Abbott

17:02 CoCoALib Bug #1376 (Closed): GBasisTimeout: not working as expected

It seems that sometimes @GBasisTimeout@ does not timeout as one would expect.
I have just interrupted (via C-c C-c... John Abbott

15:30 CoCoALib Slug #1375: Radical 0-dim: varied timings

I have modified my program to call @GBasisTimeout@, and I specified 30s as the time-out.
I was a bit surprised to fi... John Abbott

13:33 CoCoALib Slug #1375: Radical 0-dim: varied timings

Here are some more examples where it takes a long time to compute RGB after computing radical:... John Abbott

11:33 CoCoALib Slug #1375: Radical 0-dim: varied timings

The current solution (increasing the "increment" to 0.5) works well on the small examples I have tried: sometimes the... John Abbott

11:58 CoCoA-5 Slug #948: radical is slow (compared to singular) on these examples

As reported in the previous comment, example 1 was still a problem. I increased the extra time (to 2.5s), then the c... John Abbott

11:42 CoCoA-5 Slug #948: radical is slow (compared to singular) on these examples

After the change mentioned in issue #1375, the examples in comment 13 are now satisfactorily quick. The example in c... John Abbott

11 Dec 2019

15:08 CoCoALib Slug #1375 (In Progress): Radical 0-dim: varied timings

Following Anna's suggestion I moved @t0 := CpuTime();@ to just before the computation of the radical; so the time dif... John Abbott

10 Dec 2019

14:41 CoCoALib Slug #1375: Radical 0-dim: varied timings

I have done more testing. The timings really do vary from run to run.
I wrote a shell script which took exactly t... John Abbott

13:28 CoCoALib Slug #1375: Radical 0-dim: varied timings

This getting more puzzling!
Here is another example: essentially the same code as in the original description but
... John Abbott

09 Dec 2019

21:08 CoCoALib Slug #1375: Radical 0-dim: varied timings

I wanted to show the students an example where it is much better to use @IsInRadical@ than compute the radical (with ... John Abbott

21:06 CoCoALib Slug #1375 (Closed): Radical 0-dim: varied timings

I have observed some strange variations in timings when computing the RGB of a radical:... John Abbott

16:07 CoCoA-5 Feature #1374: Add function power to CoCoA-5

I am inclined to say that there is not much point in writing any tests for @power@. What do you think?
John Abbott

13:55 CoCoA-5 Feature #1374: Add function power to CoCoA-5

Should the function be documented?
If so, we should probably state that it exists just to increase compatibility b... John Abbott

13:37 CoCoA-5 Feature #1374: Add function power to CoCoA-5

If you are convinced that my approach is better, then, yes, please undo your CVS update.
I am not certain whether ... John Abbott

12:21 CoCoA-5 Feature #1374: Add function power to CoCoA-5

I have just checked in a @power@ function defined in @cocolib.cpkg5@.
My approach means that @power@ works for any t... John Abbott

13:34 CoCoALib Slug #1136: IsInRadical: sometimes a bit slow

Just for the record...
With the exponent pair (3,4), my computer takes about 2.4s whereas with the pair (4,5) it t... John Abbott

05 Dec 2019

15:55 CoCoALib Slug #1136 (Feedback): IsInRadical: sometimes a bit slow

It took about 0.08s on my computer just now. This is probably fine; I see no advantage in making it lengthier.
Move... John Abbott

15:52 CoCoALib Slug #1136: IsInRadical: sometimes a bit slow

What is the status of this issue?
Can it be closed soon?
John Abbott

04 Dec 2019

17:38 CoCoALib Bug #1233: factor SEGV -- too large characteristic

This now gives error rather than SEGV -- so that is an improvement!
John Abbott

17:19 CoCoALib Support #1161: Split NumTheory.C into several smaller files

Postponing because not important for CoCoA School.
John Abbott

17:15 ApCoCoA Feature #1328: New ApCoCoA UI

Meeting today (2019-12-04).
Nguetsa reports: Interface is working, and history mechanism too. Also interfaces well ... John Abbott

15:22 CoCoA-5 Feature #1373 (In Progress): GFan also for Microsoft?

Is it possible to make the GFan functions available in the pre-compiled release for Microsoft?
John Abbott

03 Dec 2019

14:36 CoCoA-5 Feature #1364 (Feedback): Emacs UI: start cocoa5 with system command enabled

I have checked in a cleaned-up version of the code... Anna said it worked fine for her.
Now we can test for it for... John Abbott

27 Nov 2019

22:42 CoCoA-5 Feature #1364 (In Progress): Emacs UI: start cocoa5 with system command enabled

Prototype sent to Anna via email, so she can test it.
John Abbott

15:53 CoCoALib Bug #1371: French students' example with GFan

I find it quite strange that the term ordering used to obtain the same LT(I) actually looks to be far away from lex:
... John Abbott