Decision boundary (linear)

An abstract boundary that separates input/feature fields into different sections, and thus what output should be given.

In a 2D plane with 2 features, a decision boundary will take the form of a 1d line.

Notation

The decision boundary is described by: ${\sum }_{i=1}^n(x_i{w}_i)+b=0$ (Note, $b$ is bias)

For 2 features/2 dimensions, it is: $x_1{w}_1+x_2{w}_2+\text{bias}=0$, which may be rearranged into a linear line.

For vector notation see Vector notation for weight and data