Function pca_init 

pub fn pca_init(
    data: &[f32],
    n: usize,
    d: usize,
) -> Result<Vec<[f32; 2]>, PaCMAPError>

Project n × d row-major data onto its top 2 principal components.

Returns n (PC1, PC2) score pairs.

Errors

Returns PaCMAPError::Pca if the decomposition fails or the inputs are inconsistent.