Ventana software support forum

Hi, I am still trying to run the Nitrogen cycle model, but I am facing some errors. I have a stock which is called "N uptake crop yield" and when I try to check the model it shows me an error saying that this stock is not used in the model. I am not sure how to deal with this pop-up messag...

Thank you very much for your help

Best regards

Thank you very much for your explanation. Actually, Time in the denitrification formula is indeed wrong because I added the Time variable myself in this formula --> "Denitrification = Soil NO3/ Time *(EXP(K den*"f (tem den)"*"f (teta den)"*Time))" to make fewer unit err...

Dear Tom, I tried to correct unit errors as you suggested last time. Now I have far fewer unit errors than before but still, there are some small unit errors. Now I wanted to run my model, however, it keeps showing me a "Floating point error" message. I checked how to correct this error fr...

Thank you very much for your help. I will try to fix it as you suggested.
Best regards

In the model, I converted mm/day to L/(m*m)/Day by multiplying to 10^(-6)

Thank you for your help. Here I am attaching my model. I tried to work on the model unit consistency but still facing the same error issues. In my model, the stock is mainly soil layers and inputs/outputs are water and fertilizer. I am not sure how can I deal with the error in units. I checked the m...

Thank you for your reply. You are indeed right, I think if I could correct one or two-unit errors then automatically other unit issues will be solved. However, I still could not figure out how I can do it. For example, I have a problem with units of inflows and outflows which are the inputs and outp...

Hi,

I am trying to work on errors in the unit but unfortunately, I could not eliminate them. If I solve one of the unit errors, the next one appears. I wanted to ask if I can run the model without specifying the units? Thanks

Hi, I am going to put functions on my model but I am a bit hesitant if I am doing it correctly. As an example, I am attaching here a very simple model (which is a very small part of my model) and the equation function. So basically I am trying to put my equation function in the model but I am not su...

Thank you very much for your reply. In this model case, authors stated shadow variables as constant variables

Hi, I am going to replicate one of the existing system dynamics models created using Vensim. When I was reading the model I saw several shadow variables used in the model. To my understanding, shadow variables can be used if that variable was used in the model earlier and saved in the list of variab...

Hi, I am going to replicate one of the existing system dynamics models created using Vensim. When I was reading the model I saw several shadow variables used in the model. To my understanding, shadow variables can be used if that variable was used in the model earlier and saved in the list of variab...

Thank you very much for your explanation. I have tried both approaches. For the first approach you have suggested, I had to create a Time variable because otherwise, vensim kept showing me that the Time variable wasn't expected but used. I guess Vensim has a Time variable but it did not allow me to ...

Here is my model. I have tried all the options but it still keeps showing me an error. Could you please suggest to me how to eliminate these errors? Thank you beforehand

Thank you very much for your help. I checked the units and they are in proper order. I would love to show my model but I am not sure how can I upload here my model. Below I am copying and pasting the errors that are appearing units check 1. Error in units for the following equation: #Soil temperatur...

Hi, I was trying to model the soil water dynamics. I gave the same measurement unit of cm/month for all the variables and stocks, but when I want to run it, the vensim doesn't run it and it keeps showing an error. When I opened the errors, it is most of the time about the measurement unit mismatch. ...