Maths & numbers

Power iteration for a symmetric two-by-two matrix calculator

Estimate an eigenvalue with normalized power iteration and report the final eigenpair residual.

Your numbers

Calculated on your device. Your inputs aren’t sent to us.

Your result

Ready when you are

Enter your inputs and select Calculate.

Report an issue

Behind the numbers

How this calculation works

Estimate an eigenvalue with normalized power iteration and report the final eigenpair residual.

THE FORMULAStart at (1,1)/√2, repeatedly normalize Ax, then compute xᵀAx

A worked example

The vector (1,1) is already an eigenvector of [[3,1],[1,3]] with eigenvalue 4.

Good to know

The seed must have a component along the dominant eigenspace for convergence to that eigenvalue.

Read the result

Estimate an eigenvalue with normalized power iteration and report the final eigenpair residual.

The primary result is labeled “Rayleigh estimate”. Keep the input definitions in view when comparing this result with another method.

Try a related calculation

The seed must have a component along the dominant eigenspace for convergence to that eigenvalue.

For a related exercise, try the quadratic equation solver.

A few questions, answered

How can I check the default inputs by hand?

The vector (1,1) is already an eigenvector of [[3,1],[1,3]] with eigenvalue 4.

Which rule does this calculator apply?

Start at (1,1)/√2, repeatedly normalize Ax, then compute xᵀAx

Find your calculator

Start typing to explore the library.