rohitg00/ai-engineering-from-scratch · error · ValueError

This method only works for 2x2 matrices

Error message

This method only works for 2x2 matrices

What it means

Error "This method only works for 2x2 matrices" thrown in rohitg00/ai-engineering-from-scratch.

Source

Thrown at phases/01-math-foundations/02-vectors-matrices-operations/code/matrices.py:137

    def determinant(self):
        if self.rows != self.cols:
            raise ValueError("Determinant only defined for square matrices")
        if self.shape == (1, 1):
            return self.data[0][0]
        if self.shape == (2, 2):
            return self.data[0][0] * self.data[1][1] - self.data[0][1] * self.data[1][0]
        det = 0
        for j in range(self.cols):
            minor = Matrix([
                [self.data[i][k] for k in range(self.cols) if k != j]
                for i in range(1, self.rows)
            ])
            det += ((-1) ** j) * self.data[0][j] * minor.determinant()
        return det

    def inverse_2x2(self):
        if self.shape != (2, 2):
            raise ValueError("This method only works for 2x2 matrices")
        det = self.determinant()
        if abs(det) < 1e-10:
            raise ValueError("Matrix is singular, no inverse exists")
        return Matrix([
            [self.data[1][1] / det, -self.data[0][1] / det],
            [-self.data[1][0] / det, self.data[0][0] / det]
        ])

    @staticmethod
    def identity(n):
        return Matrix([
            [1 if i == j else 0 for j in range(n)]
            for i in range(n)
        ])

    @staticmethod
    def zeros(rows, cols):
        return Matrix([[0] * cols for _ in range(rows)])

View on GitHub (pinned to 39ea8a1c6d)

When it happens

Trigger: Thrown at phases/01-math-foundations/02-vectors-matrices-operations/code/matrices.py:137 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of rohitg00/ai-engineering-from-scratch@39ea8a1c6d (2026-08-26). Data as JSON: /api/errors/ea4a16dec9ae48d1. Report an issue: GitHub.