[SCIP] Fwd: pricing in problem variables

James Cussens james.cussens at york.ac.uk
Wed May 17 14:41:10 CEST 2017


Dear Gerald,

Aha, yes my mistake - after setting verbosity to maximum I see everything
(show below). Thanks for your help!

James

    1 constraints of type <dagcluster>
Presolving Time: 6.01

 time | node  | left  |LP iter| mem |depth|mdpt |frac |cons |cols |rows
|cuts |pool |confs|strbr|  dualbound   | primalbound  |  gap
  6.5s|     1 |     0 |     0 | 235M|   0 |   0 |   0 |1275 |   0 |   0 |
0 |   0 |   0 |   0 | 0.000000e+00 |      --      |    Inf
k 6.5s|     1 |     0 |     0 | 236M|   0 |   0 |   0 |1275 |   0 |   0 |
0 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  6.9s|     1 |     0 |     0 | 278M|   0 |   0 |   - |1275 |2000 | 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  6.9s|     1 |     0 |     1 | 278M|   0 |   0 |   - |1275 |4000 | 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  6.9s|     1 |     0 |     1 | 278M|   0 |   0 |   - |1275 |6000 | 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  6.9s|     1 |     0 |     3 | 278M|   0 |   0 |   - |1275 |8000 | 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.0s|     1 |     0 |     3 | 278M|   0 |   0 |   - |1275 |  10k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.0s|     1 |     0 |     3 | 278M|   0 |   0 |   - |1275 |  12k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.0s|     1 |     0 |     3 | 278M|   0 |   0 |   - |1275 |  14k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.0s|     1 |     0 |     3 | 278M|   0 |   0 |   - |1275 |  16k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.0s|     1 |     0 |     3 | 278M|   0 |   0 |   - |1275 |  18k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.0s|     1 |     0 |     6 | 278M|   0 |   0 |   - |1275 |  20k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.0s|     1 |     0 |     9 | 278M|   0 |   0 |   - |1275 |  22k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.0s|     1 |     0 |     9 | 278M|   0 |   0 |   - |1275 |  24k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.0s|     1 |     0 |    11 | 278M|   0 |   0 |   - |1275 |  26k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
 time | node  | left  |LP iter| mem |depth|mdpt |frac |cons |cols |rows
|cuts |pool |confs|strbr|  dualbound   | primalbound  |  gap
  7.0s|     1 |     0 |    37 | 278M|   0 |   0 |   - |1275 |  28k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.0s|     1 |     0 |   271 | 278M|   0 |   0 |   7 |1275 |  30k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.1s|     1 |     0 |   512 | 278M|   0 |   0 |   7 |1275 |  30k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.1s|     1 |     0 |   556 | 278M|   0 |   0 |   7 |1275 |  30k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.1s|     1 |     0 |   559 | 278M|   0 |   0 |   7 |1275 |  30k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.2s|     1 |     0 |   560 | 278M|   0 |   0 |   7 |1275 |  30k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.2s|     1 |     0 |   562 | 278M|   0 |   0 |   7 |1275 |  30k| 300 |
300 |   0 |   0 |   0 | 0.000000e+00 |-8.017084e+04 |    Inf
  7.2s|     1 |     0 |   562 | 278M|   0 |   0 |   7 |1275 |  30k| 300 |
300 |   0 |   0 |   0 |-4.304651e+04 |-8.017084e+04 |  86.24%
  7.6s|     1 |     0 |   682 | 283M|   0 |   0 |   0 |1275 |  30k| 412 |
412 |   1 |   0 |   0 |-4.304651e+04 |-8.017084e+04 |  86.24%
  7.6s|     1 |     0 |   684 | 283M|   0 |   0 |   0 |1275 |  30k| 412 |
412 |   1 |   0 |   0 |-4.304651e+04 |-8.017084e+04 |  86.24%
  7.7s|     1 |     0 |   684 | 283M|   0 |   0 |   0 |1275 |  30k| 412 |
412 |   1 |   0 |   0 |-6.320584e+04 |-8.017084e+04 |  26.84%
  7.7s|     1 |     0 |   716 | 284M|   0 |   0 |   0 |1275 |  30k| 422 |
422 |   1 |   0 |   0 |-6.320584e+04 |-8.017084e+04 |  26.84%
  7.8s|     1 |     0 |   716 | 284M|   0 |   0 |   0 |1275 |  30k| 422 |
422 |   1 |   0 |   0 |-6.326572e+04 |-8.017084e+04 |  26.72%
k 7.8s|     1 |     0 |   716 | 284M|   0 |   0 |   0 |1275 |  30k| 422 |
422 |   1 |   0 |   0 |-6.326572e+04 |-7.975713e+04 |  26.07%
  8.1s|     1 |     0 |   784 | 303M|   0 |   0 |   0 |1275 | 508 | 522 |
522 |   4 |   0 |   0 |-6.326572e+04 |-7.975713e+04 |  26.07%


On 17 May 2017 at 07:46, Gerald Gamrath <gamrath at zib.de> wrote:

> Hi James,
>
> just a short addition: did you leave the verbosity level at default
> (high)? Then you could change it to full and see a display line after each
> pricing round. If you already set it to full before, we will need to
> investigate further to find the reason for the behavior you are
> experiencing.
>
> Best,
> Gerald
>
> Am 16.05.2017 um 21:05 schrieb Gerald Gamrath:
>
> Hi James,
>
> sorry for the late reply. Your explanation with the cuts sounds reasonable
> and could well cause this behavior, but is not the reason here, since the
> cuts are only added a bit later.
> I also needed to have a look in the code to find the cause, but in the
> end, it's quite simple: SCIP does not print a display line after each
> pricing round, but only if nrounds % 100 == 1 (and after the pricing round
> is finished, after cutting, etc.). So, the second line you see is after a
> few more pricing rounds and you end up at 30.000 variables at that point
> even if only 2000 are added each round.
>
> Best,
> Gerald
>
> Am 15.05.2017 um 11:55 schrieb James Cussens:
>
> Hi folks,
>
> Regarding my question below. I suspect now that the reason I end up with
> so many new columns is that the relevant variables are in the cuts I am
> adding. Does that make sense?
>
> James
>
>
> ---------- Forwarded message ----------
> From: James Cussens <james.cussens at york.ac.uk>
> Date: 12 May 2017 at 15:13
> Subject: pricing in problem variables
> To: scip at zib.de
>
>
> I am experimenting with setting my problem variables to be non-initial and
> having them 'priced-in'. See  below for an example of what is going on.
>
> The line where we get 2000 cols makes sense, since this is the (default)
> value of pricing/maxvarsroot = 2000. However on the next iteration we end
> up with ~30k columns.
> I don't see why we don't just end up with 4000. Can anyone illuminate me?
>
> Note that since I have also marked my variables as 'removable' most of
> them get (perhaps temporarily) removed a little later on.
>
> James
>
>
> .....
> 1 constraints of type <dagcluster>
> Presolving Time: 14.87
>
>  time | node  | left  |LP iter| mem |depth|mdpt |frac |cons |cols |rows
> |cuts |pool |confs|strbr|  dualbound   | primalbound  |  gap
>  16.6s|     1 |     0 |     2 | 249M|   0 |   0 |   - |1275 |2000 |  23 |
>   0 |   0 |   0 |   0 | 0.000000e+00 |      --      |    Inf
>  16.7s|     1 |     0 |    23 | 250M|   0 |   0 |   0 |1275 |  30k|  23 |
>   0 |   0 |   0 |   0 |-6.120109e+04 |      --      |    Inf
> k16.8s|     1 |     0 |    23 | 250M|   0 |   0 |   0 |1275 |  30k|  23 |
>   0 |   0 |   0 |   0 |-6.120109e+04 |-8.017084e+04 |  31.00%
>  17.1s|     1 |     0 |   210 | 261M|   0 |   0 |   0 |1275 |  30k| 149 |
> 126 |   8 |   0 |   0 |-6.120109e+04 |-8.017084e+04 |  31.00%
>  17.2s|     1 |     0 |   210 | 261M|   0 |   0 |   0 |1275 |  30k| 149 |
> 126 |   8 |   0 |   0 |-6.396899e+04 |-8.017084e+04 |  25.33%
>  18.1s|     1 |     0 |   444 | 288M|   0 |   0 |  58 |1275 |  30k| 288 |
> 265 |   9 |   0 |   0 |-6.396899e+04 |-8.017084e+04 |  25.33%
>  18.3s|     1 |     0 |   463 | 288M|   0 |   0 |  55 |1275 |  30k| 288 |
> 265 |   9 |   0 |   0 |-6.566947e+04 |-8.017084e+04 |  22.08%
> k18.4s|     1 |     0 |   463 | 288M|   0 |   0 |  55 |1275 |  30k| 288 |
> 265 |   9 |   0 |   0 |-6.566947e+04 |-7.959231e+04 |  21.20%
>  19.9s|     1 |     0 |  1144 | 299M|   0 |   0 | 136 |1275 |  30k| 366 |
> 343 |  10 |   0 |   0 |-6.566947e+04 |-7.959231e+04 |  21.20%
>  20.4s|     1 |     0 |  1211 | 299M|   0 |   0 | 152 |1275 |  30k| 366 |
> 343 |  10 |   0 |   0 |-6.640382e+04 |-7.959231e+04 |  19.86%
>  22.1s|     1 |     0 |  1782 | 301M|   0 |   0 | 207 |1275 |  30k| 442 |
> 419 |  11 |   0 |   0 |-6.640382e+04 |-7.959231e+04 |  19.86%
>  22.7s|     1 |     0 |  1851 | 301M|   0 |   0 | 221 |1275 |  30k| 442 |
> 419 |  11 |   0 |   0 |-6.643694e+04 |-7.959231e+04 |  19.80%
> k22.8s|     1 |     0 |  1851 | 301M|   0 |   0 | 221 |1275 |  30k| 442 |
> 419 |  11 |   0 |   0 |-6.643694e+04 |-7.919237e+04 |  19.20%
>  24.3s|     1 |     0 |  2116 | 416M|   0 |   0 | 197 |1275 | 525 | 416 |
> 469 |  38 |   0 |   0 |-6.643694e+04 |-7.919237e+04 |  19.20%
> ....
>
>
> --
> James Cussens
> Dept of Computer Science &
> York Centre for Complex Systems Analysis
> Room 326, The Hub, Deramore Lane            Tel    +44 (0)1904 325371
> <+44%201904%20325371>
> University of York                                        Fax  +44
> (0)1904 500159 <+44%201904%20500159>
> York YO10 5GE, UK
> http://www.cs.york.ac.uk/~jc
> http://www.york.ac.uk/docs/disclaimer/email.htm
>
>
>
> --
> James Cussens
> Dept of Computer Science &
> York Centre for Complex Systems Analysis
> Room 326, The Hub, Deramore Lane            Tel    +44 (0)1904 325371
> University of York                                        Fax  +44
> (0)1904 500159 <+44%201904%20500159>
> York YO10 5GE, UK
> http://www.cs.york.ac.uk/~jc
> http://www.york.ac.uk/docs/disclaimer/email.htm
>
>
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-- 
James Cussens
Dept of Computer Science &
York Centre for Complex Systems Analysis
Room 326, The Hub, Deramore Lane            Tel    +44 (0)1904 325371
University of York                                        Fax  +44 (0)1904
500159
York YO10 5GE, UK                               http://www.cs.york.ac.uk/~jc
http://www.york.ac.uk/docs/disclaimer/email.htm
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