This Milestone will allow you to run full PCA
Depends: MATRIX_OPERATIONS
-
Which library provides a way to compute
full PCA/SVD
? -
Load the dataset
######.csv
as a matrix. -
What are the dimensions of your data matrix?
-
Compute PCA on it (use scale and centering equal to TRUE). PCA will result in 2 matrices and 1 vector.
-
Check the dimensions of the matrices and vectors from PCA.
-
How many principal components do we have for this dataset?
-
Where is stored the variance captured by each PC?
-
What does the matrix samples-by-PCs mean?
-
What does the matrix features-by-PCs mean?
-
What happens if you
transpose the data matrix
before computing PCA? -
Check the dimensions of the resulting matrices and vectors from PCA.
-
How many principal components do we have for this dataset?
-
Where is stored the variance captured by each PC?
-
What does the matrix samples-by-PCs mean?
-
What does the matrix features-by-PCs mean?
This Milestone will allow you to run truncated PCA
Depends: PCA
- In the method above, we used a library to compute
full PCA/SVD
. However, in many cases computing all PCs takes a long time, so to compute only the first say20
PCs, we can compute arandomised truncated PCA/SVD
. Which library provides this PCA implementation? - Load the dataset
######.csv
as a matrix. - What are the dimensions of your data matrix?
- Compute PCA on it (use scale and centering equal to TRUE). PCA will result in 2 matrices and 1 vector.
- Check the dimensions of the matrices and vectors from PCA.
- How many principal components do we have for this dataset?
- Where is stored the variance captured by each PC?
- What does the matrix samples-by-PCs mean?
- What does the matrix features-by-PCs mean?
- What is the advantage of running truncated PCA instead of full PCA?
This Milestone will allow you to get a deeper understanding of the power of PCA
Depends: PCA_2
- How can you recreate the original data from the matrices output from PCA?
- How can you project new points into a computed PCA? You can multiply the