Error with Allocate Available

[Pruyn]

I use Allocate Available to divide available production capacity over the different projects. All worked fine untill I added a new part to my model, which is not involved in any feedback loop (yet). After I wanted to test this I got the following Error message.

ERROR: Error in ALLOCATE_AVAILABLE/FIND_MARKET_PRICE - subscript range error in request quantity.
ERROR: Floating point error computing - Potential Production[Yard10,ship2] - at time = 0.000000.
Trying to save the results anyway

Which seems strange to me, since it worked fine. I tried different time steps, different width/priorities and requests, but I keep getting this message.
I also don't know what the error points to, I use simple ranges, no subranges whatsoever.

[Administrator]

Just a quick question, do you have the subscript orders correct?

Tony.

[Pruyn]

I think so, also because before I added some new part it worked fine. But to be sure, here are the relevant equations:

Potential Priority of Ship[Yard,ship,ptype]=
1 ~~|
Potential Priority of Ship[Yard,ship,ppriority]=
zidz ( VMAX ( Time Left[Yard,ship!] ) - Time Left[Yard,ship] , VMAX ( Time Left[Yard
,ship!] ) ) ~~|
Potential Priority of Ship[Yard,ship,pwidth]=
1 ~~|
Potential Priority of Ship[Yard,ship,pextra]=
0
~ Dmnl
~ |

Potential Production[Yard,ship]=
ALLOCATE AVAILABLE(Potential Required Production[Yard,ship], Potential Priority of Ship
[Yard,ship,ptype], Production Limit for Capacity[Yard])
~ Ton/Month
~ |

Potential Required Production[Yard,ship] = xidz ( Work in Progress[Yard,ship] , Time Left
[Yard,ship] , Work in Progress[Yard,ship] / TIME STEP )
~ Ton/Month
~ |

Time Left[Yard,ship] =
0
~ Month
~ |

Work in Progress[Yard,ship] =
0
~ Ton
~ |

Production Limit for Capacity[Yard] =
100000
~ Ton/Month
~ |


Changing the values doesn't solve my problem and if I run it independently It works fine.

[Administrator]

Can you provide the values of the inputs at the time it fails? Maybe there is a combination of vals that causes the problem.

Tony.

[Pruyn]

Here are the values for the input.

Time (Month) 0
"Potential Priority of Ship[Yard,ship,PProfile]" Runs: Current
Potential Priority of Ship
[Yard10,ship1,ptype] 1
[Yard10,ship1,ppriority] --
[Yard10,ship1,pwidth] 1
[Yard10,ship1,pextra] 0
[Yard10,ship2,ptype] 1
[Yard10,ship2,ppriority] --
[Yard10,ship2,pwidth] 1
[Yard10,ship2,pextra] 0
[Yard10,ship3,ptype] 1
[Yard10,ship3,ppriority] --
[Yard10,ship3,pwidth] 1
[Yard10,ship3,pextra] 0
[Yard10,ship4,ptype] 1
[Yard10,ship4,ppriority] --
[Yard10,ship4,pwidth] 1
[Yard10,ship4,pextra] 0
[Yard10,ship5,ptype] 1
[Yard10,ship5,ppriority] --
[Yard10,ship5,pwidth] 1
[Yard10,ship5,pextra] 0

Time (Month) 0
"Potential Required Production[Yard,ship]" Runs: Current
Potential Required Production
[Yard10,ship1] 0
[Yard10,ship2] 0
[Yard10,ship3] --
[Yard10,ship4] --
[Yard10,ship5] --

Time (Month) 0
"Time Left[Yard,ship]" Runs: Current
Time Left
[Yard10,ship1] 0
[Yard10,ship2] 0
[Yard10,ship3] --
[Yard10,ship4] --
[Yard10,ship5] --

[Administrator]

Is the "Time Left" parameter a data input?

There are no values listed for ppriority (which is calculated from "time left").

Maybe the function needs actual values in the inputs before calling the function (external functions do need values or you will cause a crash).

Tony.

[bob@vensim.com]

Are you using 5.4b? There was a problem with earlier versions that used the wrong dimensions to determine size.

If you are then what are the subscript equations for ship, yard and ptype. Your equations look ok but the message indicates something is amiss (for example ship being a subrange).

[Pruyn]

I'm using 5.4b

PProfile :
ptype, ppriority, pwidth, pextra
~
~ |

ship:
(ship1-ship25)
~
~ |

Yard: (Yard1-Yard10)
~
~ |

I have searched for subranges, but can't find any.

[Pruyn]

The model will run if I change the ship subscript to ship1 only, not that's any good than.

changing to allocate by priority or another allocation type doesn't solve the problem either.

Would rebuilding the model from scratch do any good?

[Edited on 4-3-2005 by Pruyn]

[bob@vensim.com]

I just tooka look at this and everything seems fine. In fact If I simply pasted in your equations (see attached) it also simulates fine.

This suggests one of two things to me. One is the subrange problem I mentioned earlier. The second is a symbolic simultaneous relationship that is not properly detected.

If the model is one that you can email to me (bob@vensim.com obviously) I would be happy to take a look at it. If not you might want to see if you can get a nonsensitive version of the model to display the problem.

[warrick]

Hello,

Please refer to the link for background to my model:
http://www.ventanasystems.co.uk/forum/v ... 957#p22610

I am having the same error with Version 6.3 as discussed in this thread . It has been more than a decade but could you please indicate how this was resolved. Bob does the offer still stand to check the model?

I checked subscripts and divide by zeros. The error comes up with ALLOCATE AVAILABLE used to calculate electricity least cost dispatching. This ONLY occurs when I link the ALLOCATE AVAILABLE used to calculate required generation expansion upstream of least cost dispatching ALLOCATE AVAILABLE. If the output is not linked back then no problems. It is strange and seems to be a glitch of some sort. Please assist.

Regards
Warrick

[Administrator]

Please start a new thread if you have problems, this one is over ten years old and the participants have not visited the forum in many years.

[warrick]

Thank you Adminstrator. I have done so at:
http://www.ventanasystems.co.uk/forum/v ... f=2&t=6356