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ENVIConfusionMatrix::OmissionError

ENVIConfusionMatrix::OmissionError

The OmissionError function method returns the errors of omission. The result is an array with one value per class.

Errors of omission represent the fraction of values that belong to a class but were predicted to be in a different class. They are a measure of false negatives. Errors of omission are shown in the columns of the confusion matrix, except for the values along the main diagonal.

In the example confusion matrix, the errors of omission are computed as follows:

Asphalt: (0 + 0 + 0 + 12) / 2397 = 0.0050

Concrete: (4 + 1 + 0 + 0) / 337 = 0.0148

Grass: (0 + 0 + 0 + 0) / 908 = 0.000

Tree: (1 + 0 + 8 + 6) / 1099 = 0.0136

Building: (4 + 1 + 0 + 9) / 2067 = 0.0068

Example


See the following topics for code examples:

Syntax


Result = ENVIConfusionMatrix.OmissionError([, ERROR=variable])

Return Value


This function method returns the errors of omission from the confusion matrix.

Arguments


None

Keywords


ERROR (optional)

Set this keyword to a named variable that will contain any error message issued during execution of this routine. If no error occurs, the ERROR variable will be set to a null string (''). If an error occurs and the routine is a function, then the function result will be undefined.

When this keyword is not set and an error occurs, ENVI returns to the caller and execution halts. In this case, the error message is contained within !ERROR_STATE and can be caught using IDL's CATCH routine. See IDL Help for more information on !ERROR_STATE and CATCH.

See Manage Errors for more information on error handling in ENVI programming.

Version History


ENVI 5.4

Introduced

API Version


3.3

See Also


ENVIConfusionMatrix



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