Intermediate Topic 30 of 51 Math for Computing
Orthogonality and Projections
Perpendicular vectors and closest-point maps.
How it works
Vectors are orthogonal if their dot product is 0; projection of b onto a is (a·b/a·a)a; least squares projects b onto the column space of A. Gram-Schmidt builds orthonormal bases.
Where it is used
Regression, signal decomposition.
Common pitfall
Numerical Gram-Schmidt loses orthogonality; use QR via Householder.
Where it fits in the course
Orthogonality and Projections is topic 30 of 51 in Math for Computing, rated Intermediate. It follows Singular Value Decomposition. The next topic is Derivatives.
Practice and explore
- Open the interactive lesson, with a mini quiz.
- Take the Math for Computing quiz.
How to study this topic
- Read the explanation above and restate the definition in your own words.
- Open the interactive lesson and answer its mini quiz.
- Read the common pitfall, then write a short example that avoids it.
- Check your understanding in the Math for Computing quiz, and revisit the topic if you miss a question.
Frequently asked questions
What is Orthogonality and Projections?
Perpendicular vectors and closest-point maps. It belongs to Math for Computing and is an intermediate-level topic.
Where do people use Orthogonality and Projections?
Regression, signal decomposition.
What is the most common mistake with Orthogonality and Projections?
Numerical Gram-Schmidt loses orthogonality; use QR via Householder.
What should I learn before this topic?
Start with Singular Value Decomposition, the topic just before it in Math for Computing.
How can I practice it?
Answer the mini quiz in the interactive lesson, then take the Math for Computing quiz.
Is Orthogonality and Projections hard to learn?
It is an Intermediate topic. Be comfortable with the Beginner topics in this area first, then read the common pitfall carefully, since it is where most mistakes happen.
How long does it take to learn Orthogonality and Projections?
Most learners can read the explanation and finish the interactive lesson in under an hour. Fluency comes from applying the idea, so plan a few short practice sessions with the quiz.
Which topics are related to Orthogonality and Projections?
Singular Value Decomposition, Derivatives, Eigenvalues and Eigenvectors are closely connected. The full list is in the related topics section of this page.
What should I study after Orthogonality and Projections?
Continue with Derivatives, the next topic in Math for Computing.
Related topics
- Singular Value Decomposition (Math for Computing)
- Derivatives (Math for Computing)
- Eigenvalues and Eigenvectors (Math for Computing)
- Partial Derivatives and Gradients (Math for Computing)