Search found 28 matches

by sankee82
Wed May 22, 2019 2:40 pm
Forum: Vensim
Topic: FORECAST
Replies: 10
Views: 598

Re: FORECAST

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 ...
by sankee82
Tue May 21, 2019 11:44 am
Forum: Vensim
Topic: FORECAST
Replies: 10
Views: 598

Re: FORECAST

Yes! I want to use the actual value till certain time point and then predict the future.
by sankee82
Tue May 21, 2019 9:14 am
Forum: Vensim
Topic: FORECAST
Replies: 10
Views: 598

Re: FORECAST

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!
by sankee82
Tue May 21, 2019 5:31 am
Forum: Vensim
Topic: FORECAST
Replies: 10
Views: 598

Re: FORECAST

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?
by sankee82
Mon May 20, 2019 6:16 pm
Forum: Vensim
Topic: FORECAST
Replies: 10
Views: 598

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...
by sankee82
Sat May 18, 2019 4:42 pm
Forum: Vensim
Topic: Forecast
Replies: 8
Views: 542

Re: Forecast

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...
by sankee82
Tue May 14, 2019 2:20 pm
Forum: Vensim
Topic: Running with Different Timesteps
Replies: 16
Views: 944

Re: Running with Different Timesteps

Thank you!
by sankee82
Tue May 14, 2019 2:06 pm
Forum: Vensim
Topic: Running with Different Timesteps
Replies: 16
Views: 944

Re: Running with Different Timesteps

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?
by sankee82
Mon May 13, 2019 12:21 pm
Forum: Vensim
Topic: Running with Different Timesteps
Replies: 16
Views: 944

Re: Running with Different Timesteps

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

Thank you!
by sankee82
Mon May 13, 2019 6:19 am
Forum: Vensim
Topic: Running with Different Timesteps
Replies: 16
Views: 944

Re: Running with Different Timesteps

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...
by sankee82
Sun May 12, 2019 5:12 am
Forum: Vensim
Topic: Running with Different Timesteps
Replies: 16
Views: 944

Re: Running with Different Timesteps

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...
by sankee82
Sat May 11, 2019 1:48 pm
Forum: Vensim
Topic: Running with Different Timesteps
Replies: 16
Views: 944

Re: Running with Different Timesteps

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 ...
by sankee82
Fri May 03, 2019 1:56 pm
Forum: Vensim
Topic: Defination of an equation
Replies: 1
Views: 282

Defination of an equation

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?
by sankee82
Sat Apr 27, 2019 5:01 am
Forum: Vensim
Topic: Running with Different Timesteps
Replies: 16
Views: 944

Re: Running with Different Timesteps

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?
by sankee82
Fri Apr 26, 2019 6:45 pm
Forum: Vensim
Topic: Running with Different Timesteps
Replies: 16
Views: 944

Running with Different Timesteps

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
by sankee82
Wed Apr 03, 2019 6:11 am
Forum: Vensim
Topic: Please, help
Replies: 2
Views: 276

Please, help

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 ...
by sankee82
Fri Mar 15, 2019 9:24 am
Forum: Vensim
Topic: Giving Excel Data
Replies: 7
Views: 603

Re: Giving Excel Data

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...
by sankee82
Thu Mar 14, 2019 7:22 pm
Forum: Vensim
Topic: Giving Excel Data
Replies: 7
Views: 603

Re: Giving Excel Data

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?
by sankee82
Thu Mar 14, 2019 6:55 pm
Forum: Vensim
Topic: Giving Excel Data
Replies: 7
Views: 603

Giving Excel Data

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.
by sankee82
Fri Mar 01, 2019 5:40 pm
Forum: Vensim
Topic: Unable to converge simultaneous Equations at Time Error
Replies: 8
Views: 693

Re: Unable to converge simultaneous Equations at Time Error

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

Regards,
Sankeerthana.
by sankee82
Fri Mar 01, 2019 5:30 pm
Forum: Vensim
Topic: Unable to converge simultaneous Equations at Time Error
Replies: 8
Views: 693

Re: Unable to converge simultaneous Equations at Time Error

Thank you so much.

Regards,
Sankeerthana.
by sankee82
Fri Mar 01, 2019 5:03 pm
Forum: Vensim
Topic: Unable to converge simultaneous Equations at Time Error
Replies: 8
Views: 693

Re: Unable to converge simultaneous Equations at Time Error

I herewith attach the model.

Thanks and Regards,
Sankeerthana.
by sankee82
Fri Mar 01, 2019 4:29 pm
Forum: Vensim
Topic: Unable to converge simultaneous Equations at Time Error
Replies: 8
Views: 693

Unable to converge simultaneous Equations at Time Error

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...
by sankee82
Fri Mar 01, 2019 11:20 am
Forum: Vensim
Topic: Simultaneous loop error
Replies: 6
Views: 2089

Re: Simultaneous loop error

Can you please elaborate what do you mean by something analogous to timestep?
by sankee82
Sun Oct 07, 2018 12:22 pm
Forum: Vensim
Topic: Giving time series data
Replies: 12
Views: 1184

Re: Giving time series data

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.