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Last Post 26 Feb 2018 01:36 PM by  MariM
Classification to Vector -- Length attribute
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Chana Sara Ivgi



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25 Feb 2018 09:49 PM
    I used the maximum likelihood classifiers. I want to measure the length in the direction of wind of one of my classes. Is there a way to specify how to measure length?

    In addition, how is length currently measured in the algorithm?


    MariM



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    26 Feb 2018 11:58 AM
    After converting a class (ROI) to a vector layer, the length of each polygon in each class is one of the attributes that is calculated. It is just the length of the perimeter of the polygon. I am not sure how that tells you the 'length in the direction of wind'. There is the Mensuration tool in the ENVI interface that you can use to draw a line and measure the length.

    Chana Sara Ivgi



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    26 Feb 2018 12:11 PM
    Thank you for the information, it seemed it was most probably the perimeter value (and not unidirectional length), thank you for the confirmation.

    I am aware of the mensuration tool, however there are so many samples that it would be indeed painstaking in order to do that. Is there another way to measure a vector in a specific direction?

    MariM



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    26 Feb 2018 01:36 PM
    Sorry, I don't know of any tool that will automate this or calculate the distance across a polygon based on direction (assuming a node to node calculation). If it is not node to node, it would be even more complex to determine automatically.
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