In what distant deeps or skies
Burnt the fire of thine eyes?
On what wings dare he aspire?
What the hand dare seize the fire?

And what shoulder, and what art,
Could twist the sinews of thy heart?
And when thy heart began to beat,
What dread hand? and what dread feet?

What the hammer? what the chain?
In what furnace was thy brain?
What the anvil? what dread grasp
Dare its deadly terrors clasp?

When the stars threw down their spears,
And water'd heaven with their tears,
Did he smile his work to see?
Did he who made the Lamb make thee?

Tyger! Tyger! burning bright
In the forests of the night,
What immortal hand or eye
Could frame thy fearful symmetry?

In what MATLAB workspace keep
Thine entries vast, thine SVD?
On what code dare he aspire?
As thy pivots grow yet higher?

And what Householder reflection
Could keep error bounds perfection?
When thy eigenvalues beat,
Can we reconstruct thy shape?

What the etree? what the path?
In what space thine eigen hath?
What the platform? What dread code
Dare its entries in core hold?

When pivots threw down their cliques,
And maxed out memory with their fill,
Did he smile his work to see?
Did he code UMFPACK just for thee?

Matryx! Factyrs! left and right
In space R to n affright,
What LU, Chol, QR, try
To keep thy fearful symmetry?