The Match sample plots block allows you to take two feature collections of sample plots and match the plots based on the similarity of their attributes.
The block uses a k-nearest neighbour (kNN) algorithm to match the plots. These plots are matched 'without replacement' meaning that they cannot be matched more than once.
The ID of the matched plot from the matching dataset is added as a new attribute “matched-uid” to the input feature collection.
When carrying out a VCS Methodology VM0047 Afforestation, Reforestation, and Revegetation assessment, use this block to match your ‘Control plots’ and ‘Project plots’ feature collections.
If you are undertaking a VM0047 assessment, use the feature collection containing the control plots as your input dataset, and add the Match sample plots block to the workflow.
Learn more: Generate sample plots block
Match with dataset
Select the dataset to match plots (features) with. This dataset must have an ID attribute named “uid”. This is applied automatically to datasets created using the Generate sample plots block.
If you are undertaking a VM0047 assessment, select the feature collection containing the project plots.
Find matches
Select the number of matches for each plot in the input dataset. This is the ‘k’ value in the ‘k-nearest neighbour’ matching approach.
Using attributes
Choose the attributes used to determine similarity.
If you are undertaking a VM0047 assessment, this must include attributes created from the stocking index.
Distance method
Select the method used for the ‘nearest neighbour’ calculation:
- Euclidean
- Cosine
- Manhattan
Viewing your results
To view your dataset with matched plots, add the Create table block into the workflow underneath the Match plots block, and view the results on the dashboard tab.
To export this dataset, add the Export dataset block underneath the Match plots block.