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Help with batch processing

Dear all,

I'm trying to create a loop within the carbon model to test the effect of LULC changes and different carbon prices/discount rates on the value of the ES. Since I'm a beginner with python, I followed the tutorial for batch processing ( and tried to implement the examples (Example: Threshold Flow Accumulation Parameter Study, and the Example: Invoke NDR Model on a directory of Land Cover Maps) using the training data available for the NDR model (Please find attached the py scripts).

However, after run the script of the first example (where I replaced the execution call by the script provided with the loop), I got the results of only one simulation, rather than the results of 10 simulations, as referred in the example.
In the second one, I have created a folder where I put the LULC maps to test and replaced the call line (modifying the directory path). In this case, I received an error:

C:\Users\ASIL>C:\Python27\python.exe C:\Users\ASIL\Desktop\testeNDR\run2\
  File "C:\Users\ASIL\Desktop\testeNDR\run2\", line 28
    landcover_dir = r'C:\Users\ASIL\Work\InVEST training data\LULC'
IndentationError: unexpected indent

I would like to know what is wrong with the scripts. Thanks in advance.



  • Hi again,

    good news, both issues are solved :)

    In the first one, I found a typo in the loop, should be args['results_suffix'] = 'accum' + str(threshold_flow_accumulation) ... instead of args['suffix'] = 'accum' + str(threshold_flow_accumulation). Then when I run the model all the simulations have been saved.

    In the second script, I have corrected the position of the line, as well as the args typo above.

    Endurance testing: Done ;)

  • jdouglassjdouglass Administrator, NatCap Staff
    Great to hear you were able to get that working!
  • AngeloAngelo Member
    edited February 12
    Hi all,

    I'm testing the effect of multiple LULC scenarios over time, and C prices and discount rates on C seq and C seq value. I have tested successfully multiple combinations of C price and discount rates following the tutorial for batch processing.

    However, I couldn't find a way to loop through LULC scenarios (and repetitions)! For calculating C seq, I have to set carbon model parameters for current and future LULC (while in the tutorial the NDR model requires only one LULC file).

    I tried some things (probably not the best method, but...)... I used the os.walk() function to extract the path of each LULC file, and then, for each Run, I extracted pairs of file paths that correspond to LULC in different dates (e.g. decade_0 and decade_1) to a text file, and use them as LULC current and future inputs. However, when I try to extract the content (ie. the LULC file path) of the text file and assign it to the model args['lulc_cur_path'] and args['lulc_fut_path'] it doesn't work... Also, args[lulc_cur/fut_year] have to change according to each LULC scenario... So, many things...

    Any idea how to do this?


    Post edited by Angelo on
  • jdouglassjdouglass Administrator, NatCap Staff
    Hey Angelo,

    One of several issues with the script is the usage of 'print'.  In python 2.7, this will raise a SyntaxError, and in Python 3, your landcover args keys will end up having a value of 'None' (this is because the print() function returns None).

    I've put together a small python script (see attached) for how you could iterate over pairs of landcover files in the list of files you sent.
  • Hi James,

    Well, thanks for the explanation and many thanks for the script. 
    However, an error occurred (see attached file please).


    1796 x 936 - 319K
  • jdouglassjdouglass Administrator, NatCap Staff
    Whoops, forgot a zip() there.  So that iteration line should read:

    for current_lulc_path, future_lulc_path in zip(landcover_files[:-1], landcover_files[1:]):
  • Hi James,

    many thanks for the help, finally I finished the script and it worked!
    However, I opted to not use the text file to select the path for each land cover map (I had some troubles when reading the text file). Instead, I selected each pair of land cover maps directly from the list that was created with os.walk for each run within each land cover scenario, and simultaneously added the correspondent current and future year! Also included a loop for the price of carbon (3x) and the discount rate (3x)!

    Now almost 4400 simulations were run in less than two days!!! :)

  • jdouglassjdouglass Administrator, NatCap Staff
    Great!  Glad to hear that everything ran smoothly :)
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