Search found 60 matches

by kong17
Wed Oct 20, 2021 2:40 pm
Forum: Vensim
Topic: Question about Optimisation of Calibration
Replies: 1
Views: 1282

Question about Optimisation of Calibration

Hi everyone I am trying to calibrate my model. According to the Help in the Vensim, I have imported the data in the model. Untitled.png And The payoff of Calibration and All the parameters of Optimization have been set. But, When I run the model, it shows the error. Untitled1.png I was wondering wha...
by kong17
Tue Aug 03, 2021 9:39 pm
Forum: Vensim
Topic: I'm having the following problem
Replies: 20
Views: 4482

Re: I'm having the following problem

The model you uploaded loads fine for me in 8.1.0 as well. If the big model is sensitive, you can send it to vensim@vensim.com and I can take a look. It may be that the error is pointing to a different parameter. Thank you. I will send it later. But I think the model is fine. The error seems to hav...
by kong17
Tue Aug 03, 2021 8:52 pm
Forum: Vensim
Topic: I'm having the following problem
Replies: 20
Views: 4482

Re: I'm having the following problem

Administrator wrote: Tue Aug 03, 2021 8:45 pm No, it's not because your licence has expired.

That model opens fine for me. What is the exact version of Vensim you are using and I'll try that.
Thank you for your reply.
The following figure shows the version that I used.
2.png
2.png (7.7 KiB) Viewed 4376 times
Thank you for your help.
by kong17
Tue Aug 03, 2021 8:24 pm
Forum: Vensim
Topic: I'm having the following problem
Replies: 20
Views: 4482

Re: I'm having the following problem

Can you upload the model? Is one of the parameters (max capacity..., effect of gener..... or capacty for CM a lookup table? Thank you for your reply. I only uploaded the part that was reported the error in my model. I have tested it, the same structure, it works in the single precision. I also down...
by kong17
Tue Aug 03, 2021 6:45 pm
Forum: Vensim
Topic: I'm having the following problem
Replies: 20
Views: 4482

Re: I'm having the following problem

There shouldn't be any difference between single and double precision with respect to syntax. Not knowing what the specific error is, it's hard to say more. I might find why I couldn't open my model in the double precision. I copy the ALLOCATE BY PRIORITY function in my single precision to double p...
by kong17
Thu Jul 29, 2021 7:41 pm
Forum: Vensim
Topic: I'm having the following problem
Replies: 20
Views: 4482

Re: I'm having the following problem

tomfid wrote: Thu Jul 29, 2021 6:04 pm There shouldn't be any difference between single and double precision with respect to syntax. Not knowing what the specific error is, it's hard to say more.
Ok, I see.
Thank you for your help.
by kong17
Thu Jul 29, 2021 5:31 pm
Forum: Vensim
Topic: I'm having the following problem
Replies: 20
Views: 4482

Re: I'm having the following problem

If you're getting a syntax error in double precision, after successfully opening it earlier, the file is probably corrupted somehow. The version you posted here works fine for me, especially after the ELMCOUNT change. Thanks, it works very well. By the way, If I try to solve the syntax error, which...
by kong17
Thu Jul 29, 2021 2:40 pm
Forum: Vensim
Topic: I'm having the following problem
Replies: 20
Views: 4482

Re: I'm having the following problem

Administrator wrote: Thu Jul 29, 2021 2:06 pm Can you try it in double precision version of Vensim?
Hi, I try to open my model in double precision that I download the new version. But, it said 'Syntax Error'.
I can open it in the prevision version (Vensim 7.3.5 single precision).
I was wondering what's wrong with it?
Thank you for your help.
by kong17
Thu Jul 29, 2021 2:32 pm
Forum: Vensim
Topic: I'm having the following problem
Replies: 20
Views: 4482

Re: I'm having the following problem

Administrator wrote: Thu Jul 29, 2021 2:06 pm Can you try it in double precision version of Vensim?
Hi, I download the double precision.
It doesn't get an error anymore.
But, I was wondering why some results are only shown one subscript?
2.png
2.png (39.06 KiB) Viewed 4463 times
FIND ZERO.mdl
(5.83 KiB) Downloaded 134 times
by kong17
Thu Jul 29, 2021 2:20 pm
Forum: Vensim
Topic: I'm having the following problem
Replies: 20
Views: 4482

Re: I'm having the following problem

tomfid wrote: Thu Jul 29, 2021 12:14 pm I don't get an error. What version are you using?
Thank you for your reply.
My version is DSS.
It stills get an error.
Untitled.png
Untitled.png (82.86 KiB) Viewed 4465 times
by kong17
Thu Jul 29, 2021 2:16 pm
Forum: Vensim
Topic: I'm having the following problem
Replies: 20
Views: 4482

Re: I'm having the following problem

Administrator wrote: Thu Jul 29, 2021 2:06 pm Can you try it in double precision version of Vensim?
Hi, Thank you for your reply.
I was wondering what is the double-precision version? Do I need to redownload?
by kong17
Thu Jul 29, 2021 12:30 pm
Forum: Vensim
Topic: I'm having the following problem
Replies: 20
Views: 4482

Re: I'm having the following problem

Thank you for your reply.
My version is DSS.
It stills get an error.
Untitled.png
Untitled.png (82.86 KiB) Viewed 4474 times
by kong17
Thu Jul 29, 2021 10:47 am
Forum: Vensim
Topic: I'm having the following problem
Replies: 20
Views: 4482

I'm having the following problem

Hello everyone, In one part of my model, I need to use the Find Zero Function. Because too many variables are calculated, I use subscripts to simplify the model, but an error occurs during runtime (Floating point overflow - saving to time 0.00000). The attachment is a simple example. I was wondering...
by kong17
Thu Feb 18, 2021 10:58 pm
Forum: Vensim
Topic: Allocation function failed to converge computing
Replies: 5
Views: 2836

Re: Allocation function failed to converge computing

One possible cause might be having a lot of "distant" priorities with a narrow width parameter, though that shouldn't be a problem with a smooth shape parameter (type 3, Normal). Another possibility might be large differences (orders of magnitude) in the range of priorities. Hi, I also ha...
by kong17
Sat Feb 06, 2021 10:01 pm
Forum: Vensim
Topic: Find Zero function
Replies: 1
Views: 1102

Find Zero function

Dear I try to build a model about electricity market. For the investment in the new power plant, I use the IRR calculated by the NPV to evaluate. Therefore, in each year, I need to calculate the IRR from the current annual income and points. So I used FIND ZERO function in vensim. The problem now is...
by kong17
Wed Nov 25, 2020 1:11 am
Forum: Vensim
Topic: The question about moving average
Replies: 1
Views: 1145

The question about moving average

Hi, everyone Maybe the question is simple, but I am completely baffled into it. I want to observe the daily price of electricity. And calculate the profit for a year. I run the model with a time step of 1 day, then aggregating profits up to a year. I found other posts about moving average in the for...
by kong17
Mon Oct 12, 2020 3:48 pm
Forum: Vensim
Topic: How to use level to calculate annual value
Replies: 7
Views: 3127

Re: How to use level to calculate annual value

1. The equation above from the lit gives cumulative profits, not annual profits. For annual profits, you need an outflow of profit from a year ago. Typically, I use something like: profit = revenue - expenses previous profit = DELAY FIXED( profit, one year, 0 ) annual profit = INTEG(profit-previous...
by kong17
Mon Oct 12, 2020 1:44 pm
Forum: Vensim
Topic: How to use level to calculate annual value
Replies: 7
Views: 3127

Re: How to use level to calculate annual value

You can enter zero as the initial value of the profit. Have you tried that? The current model enter zero as the initial value of the profit. It could work, but, the profits are always accumulating. and what I hope to calculate is annual profit. For example, the annual profit in the first year is 50...
by kong17
Mon Oct 12, 2020 1:25 pm
Forum: Vensim
Topic: How to use level to calculate annual value
Replies: 7
Views: 3127

How to use level to calculate annual value

Hi, everyone From the literature, I see that many people use integration to calculate annual profits Looks like: equation.png Because I used discrete points to calculate daily profits, and then accumulate annual profits. But the more discrete points are set, the more troublesome the model becomes. T...
by kong17
Thu Aug 06, 2020 5:46 pm
Forum: Vensim
Topic: The question aboujt time step and units for Time
Replies: 1
Views: 1242

The question aboujt time step and units for Time

Hi, everyone Maybe the question is simple, but I am completely baffled into it. I want to observe the hourly price of electricity. And calculate the profit for a year. If the units for time is set to year and the time step is set to hour (1/8760). when the time boundaries are slightly longer, the so...
by kong17
Wed Jun 24, 2020 2:08 pm
Forum: Vensim
Topic: A question about Find Zero Function
Replies: 2
Views: 1516

Re: A question about Find Zero Function

I think the problem is that this is numerically cranky as formulated. Your NPV has a scale ~ investment, i.e. billions, while your x scale parameter is set to 1. Zeroing the npv to the nearest dollar is hard (and a waste of computation since the prospective NPV of a project is never certain). Set x...
by kong17
Tue Jun 23, 2020 1:09 pm
Forum: Vensim
Topic: A question about Find Zero Function
Replies: 2
Views: 1516

A question about Find Zero Function

Hi everyone I have a question about the function of FIND ZERO The model I tried to build calculates IRR based on current profits, to assess whether there is any appeal for investment. Vensim has an IRR function, but his results are more about showing the evolution of the results. Therefore, I consid...
by kong17
Sat May 09, 2020 11:34 am
Forum: Vensim
Topic: The subscripts problem in aging structure
Replies: 4
Views: 2121

Re: The subscripts problem in aging structure

It seems like you're doubling up on vintaging here. If you have explicit stocks for vintages, you don't need to repeat that in the subscripts. The subscript range could simply represent wind, solar, etc. But for the capacity in different periods, it also caused the difference in efficiency and cost...
by kong17
Fri May 08, 2020 5:31 pm
Forum: Vensim
Topic: The subscripts problem in aging structure
Replies: 4
Views: 2121

The subscripts problem in aging structure

Hi everyone, I am working on generation capacity expasnion model. In order to the difference in efficiency between old and new capacity. So, the aging structure is consdered in the model. There are 3 vintages in the uploaed simple model. My question is due to different subscripts for each vintage, t...
by kong17
Thu May 07, 2020 9:09 pm
Forum: Vensim
Topic: A question about GET XLS DATA
Replies: 16
Views: 5641

Re: A question about GET XLS DATA

I'm disenchanted with the cloud versions of Excel, which seem to get flakier with each update. I've switched my GET XLS protocol to Direct (on the Settings tab of Tools>Options). That makes GET XLS work like GET DIRECT. The downside is that the file can't be open in Excel. The benefit is that these...