“…Certainly, the corresponding BMU associated with each input sample of the input feature space 𝑋 can be determined by measuring the Euclidean distance following Equation (18), where 𝑥 = (𝑥 , … , 𝑥 , … , 𝑥 ) is a sample that belongs to the training input feature space 𝑋 . To quantify the quality of adaptation achieved with the mapping through the SOM, the deviation between the BMUs and the input feature vectors is measured with two metrics, the quantization error (𝐸 ) and the topological error (𝐸 ), described with Equations ( 19) and (20), respectively. This is where each 𝑥 represents each one of the features of the input feature space 𝑋 , whereas each vector jth in the output neuron grid is represented by 𝑚 , and 𝑢(𝑥 ) is equal to 1 when the two first-evaluated BMUs for 𝑥 are adjacent (are not close between them); otherwise, 𝑢(𝑥 ) is equal to 0.…”