DSSAT-Pythia Installation Guide

Software Requirements

To install and run DSSAT-Pythia on your PC, you will need the following software:

1. DSSAT:
   Download and install DSSAT from DSSAT website.

2. Python 3.8:
   Download the Python 3.8 installer for Windows or macOS from Python 3.8 release page.

   • During installation, select “Customize installation.”
   • Select all options under “Optional Features” and “Advanced Options.”
   • Note: DSSAT-Pythia only works with Python 3.8. If you have another version, uninstall it and download Python 3.8 from the above link.

3. Git:
   Download and install Git from Git download page.

4. Community Version of Visual Studio:
   Download and install Visual Studio from Visual Studio website.
   Select the Desktop development with C++ workload during installation.

5. RStudio:
   To use RStudio on your PC, install both R and RStudio:

   • Download and install R from CRAN website.
   • Download and install RStudio from RStudio website.

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Steps to Install DSSAT-Pythia on PC

1. Enable Developer Mode:

   • Open Windows Settings > Update & Security > For Developers.
   • Switch on Developer Mode and restart the computer.

2. Open the Command Prompt in the C Drive:

   • Open the C drive and type cmd in the address bar and press Enter.

3. Clone the DSSAT-Pythia repository:

   git clone https://github.com/dssat/pythia.git pythia

4. Navigate to the cloned directory:

   cd pythia

5. Delete the poetry.lock file:

   del poetry.lock

6. Install Poetry:

   pip install poetry

7. Install DSSAT-Pythia:

   <full path to poetry>\poetry install
   <full path to poetry>\poetry build

   • On Windows, poetry will be found in "C:\Users\username\AppData\Local\Programs\Python\Python38\Scripts"

8. Install the Pythia wheel file:

   • Navigate to the dist folder and install the .whl file:

     cd dist
     pip install pythia-2.3.0-py3-none-any.whl

   • Note: Check the version in the dist folder and adjust the command if necessary.

9. Add the path to pythia.exe to your environment variables.

10. Close the command prompt.

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Troubleshooting

• If you encounter any issues during installation, delete the folder C:\pythia and repeat the installation steps.

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Input Files Setup

1. Download the InputFiles.zip folder from Google Drive link, unzip it, and save the Simulation_Data folder in C:\pythia\.

2. Open the folder C:\pythia\Simulation_Data\OUTPUT\Sri_Lanka and remove all folders (if any).

   Note: Remove the contents from the OUTPUT folder every time you run the model.

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Running the Model

1. Open the command prompt at C:\pythia\Simulation_Data\Sri_Lanka by typing cmd in the folder address bar.

2. Run the following commands to simulate maize and rice:

   pythia --all C:/pythia/Simulation_Data/Sri_Lanka/SL_Maize.json
   pythia --all C:/pythia/Simulation_Data/Sri_Lanka/SL_Rice.json

3. To view the output:

   • Open the .json file in C:\pythia\Simulation_Data\Sri_Lanka\.
   • Find the working directory in "workDir": "C:/pythia/Simulation_Data/OUTPUT/Sri_Lanka/…" and navigate to that folder.
   • The output will be available in .csv format.

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Plotting Output in RStudio

1. Open the R code file: C:\pythia\Simulation_Data\OUTPUT\ACASA_Sri_Lanka_maize.R.

2. Install all required packages and modify the file location on line 22 to match the output .csv file.

3. Run the R script to generate the yield plot.

4. The plot will be saved at the location specified in line 62.

   Note: If you encounter errors reading the .csv file, open the file and delete all columns except LATITUDE, LONGITUDE, and HWAH.