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Principal component analysis, a technique for dimensionality reduction.
1
vote
Accepted
Principle Component Analysis on multiple functions
Variations of PCA can still be applicable.
If the data is not linear, use nonlinear PCA.
It is not an issue there a multiple "y"s for every "x". PCA is unsupervised, there is no notion of targets. … In PCA, there are only dimensions.
Typically, the dimensions are standardized so each dimension can be weighted independent of scale.
One caveat - PCA is domain agnostic. …
2
votes
Accepted
Ploting eigenvectors
The PCA projections do not look not orthogonal because your figure axes are not equal. …
1
vote
PCA scikit-learn - ValueError: array must not contain infs or NaNs
From scikit-learn's PCA docs:
When True (False by default) the components_ vectors are multiplied by
the square root of n_samples…
That creates an overflow issue which results in the ValueError …
1
vote
Higher variance in PCA can mean, that data structure is less informative?
It is not the best use of Principal Component Analysis (PCA) to compare information loss for different data structures.
It would be more appropriate to use Information Theory. …
1
vote
t-SNE on extremely high-dimensional spaces
There is no theoretical upper bound for t-SNE. However, pragmatically it will become increasingly computationally impracticable to reduce higher and higher dimensions to lower and lower dimensions. Th …
0
votes
How to tell how much information I lose when I simplify the graph data structure with respec...
Graph comparisons can be tricky.
One option is to take an Information Theory approach, something like "An information-theoretic, all-scales approach to comparing networks"
1
vote
Accepted
Dimensionality reduction with prior knowledge of colinearity between features
One option is to use Multidimensional scaling (MDS) for dimensionality reduction. MDS can create a visualization of the relative positions for data based on the distance between the data points.
In y …
5
votes
Accepted
can I use t-sne or PCA to reduce number of classes?
No. t-Distributed Stochastic Neighbor Embedding (t-SNE) and Principal Component Analysis (PCA) are dimension reduction techniques, aka fewer columns of a tidy dataframe. …
1
vote
Eigenvalues of covariance matrix are negative
That is probably a result of a floating point error.
The matrix is 60,000 x 20 and sparse (mostly zeros). The result of the calculations are values very close to zero that are not correctly represente …
0
votes
Practical Interpretation of PCAs for a supplier analysis
Principal Component Analysis (PCA) is not very useful for that type of interpretation. …
1
vote
Should Principal components be normalized before applying K means on them?
No - There is no need to normalize after Principal Component Analysis (PCA) because each dimension is on the same scale. …
1
vote
PCA huge parts of missing data filling
Principal component analysis (PCA) is not designed for time series data. It would be better to switch to singular spectrum analysis (SSA) which is designed for time series. …
1
vote
How is PCA applied to (one-hot encoded) DNA sequence data?
The paper is incorrect in applying Principal Component Analysis (PCA) to boolean data since PCA implicitly minimizes a squared loss function, which is not always appropriate for not real-valued data. …
2
votes
Distributed PCA or an equivalent
There is principal component analysis (PCA) in Spark's
Machine Learning Library (MLlib). …
2
votes
Using PCA as features for production
In scikit-learn, PCA has the fit_transform method which fits and applies the dimensionality reduction to the training data. There is also transform which only applies the dimensionality reduction. …