Ventana software support forum

Thank you for the response. If I want to forecast the model for future time, is it necessary to give all the inputs till the end of future time? For example in the above model attached variables like Rainfall Intensity, Canal Water Release Rate, Temperature were given as direct inputs and when I am ...

Yes! I want to use the actual value till certain time point and then predict the future.

I am trying to forecast "GW Storage", which is defines as a level. I am also interested in forecasting the other variables like Annual Yield, Annual Irrigation Cost per ha, etc.
Thank you!

Thanks for the response. I am herewith attaching the model. Can you please also elaborate the meaning of average time and Horizon used in FORECAST function? Is there any other function which can predict the future more effectively than FORECAST?

Hi! I have developed a model by giving the inputs of past 20 years. Now I want to predict the future by using FORECAST function. But when I am using FORECAST, the model starts predicting from the starting time instead of continuing from the Final Time step. Can you please help me in fixing this? The...

Hi! I am also trying to forecast the future variables by using the historic data. In my case my variable of interest is modeled as a level whereas In the above case the order cycle was a lookup. Can you please suggest me how to use the above algorithm for a level/stock i.e., Auxiliary variable? Than...

Thank you!

Thank you so much for the response. To simulate Harvest as annual discrete event, I am using a reporting interval of 365 days. But I am running the model for 20 years. How should I account for leap years which have 366 days and give reporting interval as 366 days for those particular years?

It is not EvapoTranspiration, it is Actual Evapotranspiration. I am also attaching the file that has source data.

Thank you!

Thank you for the response. Can you please also help me with why the annual crop yield reduction is being calculated using every 365th value of crop yield reduction whereas I want to accumulate the crop yield on annual basis after every 365 days. Also instead of accumulating crop yield I rather want...

Thank you fro the response. AET is Actual Evapotranspiration and PET is Potential Evapotranspiration whose units are m/day. In the attached model, I have corrected the units for all the variables except farm balance since I am confused about how to define those variables. Can you please help me with...

Hello everyone! In the model attached, I have tried to accumulate the crop yield on annual basis after every 365 days. But from my observation the annual crop yield reduction is being calculated using every 365th value of crop yield reduction. Can you please help me in solving this? Also instead of ...

Is there any way to define a variable as the difference of the value of another variable/level in the present cycle and the previous cycle?

In the model attached, I want to run the hydrological parameters on daily timestep as I have daily data. Whereas, I want to calculate the crop yield at the end of each year. Can you please help me with it? Can the functions related to DELAY be of any help?

Hello Everyone,

Is it possible to run one part of my model on daily time step and the other part of it on yearly time step?

Thanks and Regards,
Sankeerthana

I am also facing similar issue. The value of my stock i.e., Soil Moisture is increasing rapidly and it has reached unimaginable values. And the model is showing a Floating point error after Timestep 64 for the flow Deep Percolation. I am unable to figure out why is this happening. I am attaching my ...

While giving GET XLS DATA command, the format is GET XLS DATA( {'filename'} , {'tabname'} , {'time_row_or_col'} , {'first_data_cell'} ) where time row/column is the row/column that stores the value of the variable. Then how is Vensim matching the units of the date as I am not providing any informati...

Thank you so much. Can you please let me know how to make sure that the time period is same for both the model and data available?

When I am trying to give excel data to the variables of my model, it is giving an error that 'Simulation starts before first time for exogenous variable' and the table of that variable is not showing any values. Can you please help me with this?

Thanks and Regards,
Sankeerthana.

Yeah I guess. I will convert it into one variable. Thank you.

Regards,
Sankeerthana.

Thank you so much.

Regards,
Sankeerthana.

I herewith attach the model.

Thanks and Regards,
Sankeerthana.

Dear forum members, I tried developing a model which has a feedback loop. As it was showing simultaneous equations error, I tried using SIMULTANEOUS function. Then it started showing 'Unable to Converge Simultaneous Equations at Time t error'. In order to avoid that I converted one of the variable i...

Can you please elaborate what do you mean by something analogous to timestep?

I am unable to understand how to use the imported data in writing equations involving time series. Can you please help me with it. I know this is very small thing to ask for, but as I am new to Vensim it is talking me a lot of time to figure out.