What is the geometrical representation of the y value in a 2-variable perceptron plot?
in the context of binary classification, Y indicate the point at ($x_1,x_2$) belongs to positive(1) or negative(-1)

this piece of code is helpful to understand this

import numpy as np
import random
def generate_data(no_points):
    X = np.zeros(shape=(no_points, 2))
    Y = np.zeros(shape=no_points)
    for ii in range(no_points):
        X[ii][0] = random.randint(1,9)+0.5
        X[ii][1] = random.randint(1,9)+0.5
        Y[ii] = 1 if X[ii][0]+X[ii][1] &gt;= 13 else -1
    return X, Y
X, Y = generate_data(100)
plt.scatter(X[:,0],X[:,1],c=Y)




in this figure, positive(1) class is shown as yellow, and negative(-1) class is shown as purple.