Ventana software support forum

Hi, I am looking through the help docs and the .cin explanation omits a discussion of how to create a .cin file. I am in the simulation control dialog and the Constants and lookups field has a +. If I click that, it tries to open a .cin, not create one. Is there an example .cin of a simple set of va...

Hi Admin and Tomfid, I am looking through SILS for the first time. I see the help button redirecting to Oliva's page with publications. In reading, I feel like I need a better foundational understanding of the EEA from Forrester 1984 and SILS from Oliva 2004. Are there any recommendations on where t...

I finally got around to downloading the update. Wow! It is getting so much closer to an IDE for other programming paradigms. I know a lot has changed, and there are probably things I will have trouble figuring out, but the equation editor feels much more intuitive to me. Great work!

I stared at this long enough and found the answer. The question of propagation, which I thought I should avoid in this post - https://www.ventanasystems.co.uk/forum/viewtopic.php?t=8438 - was actually the solution. As soon as the user implements a for loop using 'var = sum(something[subscript!])' th...

Admin, if you want to take a crack at this, it may be useful. I am trying to figure out why the toy model here is a constant output instead of a changing output. When I introduced 3 subscripts, instead of 2, it became a constant. The only thing I tried to change was making a selection for array size...

Tom, In trying to integrate this application with a larger model, I am adding the function to select the array size, which will define the g-function from table data. Unfortunately, how I have it currently set up, the output of the function is not correct and is unchanging. I am not sure what is wro...

Ok, I solved my own problem. The starting point of the subscript use needed to be added to the Excel data variable. I also omitted a few subequations in the first posting of the mdl. Here is the corrected .mdl, that will run.

Removing the subscripts from the left hand side did not prevent the error. The equation still returns "Incorrect number of subscripts for -gfunct subscript-." I am posting a smaller version of this model to troubleshoot here. A change from some posts that Tom had previously helped me work ...

So far as I can tell, it is not true that SUM() prevents the propagation of subscripts in subsequent equations. I cannot get anything to run, whatever the case, but here is one example where SUM() is doing nothing to prevent propagation of subscripts: Gives "incorrect number of subscripts for g...

Yes, that makes sense. I am not sure why I mentioned FINAL TIME. Thank you for the clarification.

In working on a larger implementation of this method, I have encountered two situations prompting two different questions. 1. If there are elements nested inside of a subscript (e.g., i1, i2, i3, etc.) and I wish to nest (different) elements inside of a different subscript, do I have to change the n...

This is cool. The dynamics now seem to match very closely. It does seem like there's a small bias in the slopes, but seems like that could arise from the Tb->Tf calculation? Also some unit issues to sort out. Hi Tom, This is what I am seeing too. These functions are not great for short time simulat...

I do see that the error is quite large for the first 200 hours or so. I will focus on that.

Reattaching all updated model files and datasets.

Hi Tom, Yes, ts should be a very big number. When you asked this question, it prompted a bucket of bolts to break loose in my brain. I do see that t, of ln(t/ts) is in hours, and it should be the equivalent seconds. So, it appears that it was not ts that was wrong, but t itself. I have added the var...

I tried tidying this up a bit with a dynamic differential temperature, but the parameterization is not simple to achieve a match. The upward or downward trend is still absent.

I worked on a few things within this and found an error in an equation for ts, where a_s should be in Joules, not kJ. Otherwise, none of the models actually work. It is apparent that the temporal superposition is not being respected so there is effectively no trend up or down in the temperature over...

Ok - I think I see that the variable is simply meant to represent ts. ts is very important for validation in that this term is attached to the dimensions and diffusion of the borehole configuration. I am attaching a modification of the model with an assumed match to the validation run. There is caus...

Hi Tom, I will be honest in that I have no idea what the significance of your 'time scale ts' variable is, but when it is moved to a value of 1 the pattern of temperature response matches perfectly. The amplitude of that response is way off, of course. I really have no idea what to do here as it see...

Also ... why does the "load on ground" column C2 in hourlyOutputs differ from the validation_W_m load? Without looking at this in detail, it is likely the performance curve for the vapor compression cycle. These can differ quite a bit from one piece of equipment to another. Adding complex...

I am uploading a modified copy of the valid data and the modified log memory 3 model. Looking at the original subscript method created, it is hard to match anything in Vensim to the existing industry software output. The quest continues, I guess. VALIDATION_log memory 3.mdl Validation_W_m.xlsx Hourl...

Here I have roughed in the fluid temperatures from the log memory 3 model and compared it to a valid simulation run. It is odd, the valid simulation tracks sometimes with the assumptions before the relationship collapses. There is something a bit convoluted about this comparison, however, in that th...

Hi Tom, I ran a valid-ish comparison with new g-functions. It is not quite identical, in that I am comparing the fluid temperature (from valid simulation) to the borehole wall temperature, but the trend should be similar. I would need to spend some more time with manual data entry and calculations o...

Hi Tom, Thanks for sending this over. That certainly looks interesting. I will have another cleared eyed look at it when I get off the road. This is something that may be worth validating on its own, which would only take about 4 hours. I still have to wrap my head around it more, but the whole thin...

I took a look at the savelist functionality in the documentation and the example models. I think the example I was looking at was under the VensimDemo/Finance folder. It does not appear to have any functionality applicable for this problem. I do not have apriori knowledge of the quantities of energy...