Why after programming the coeff of the dataset, I get only part of the coeff of the dataset?

There is a 20*7 dataset and i try to get the coeff of it. But after I run the program, the output only provides me with a 7*7 coeff array.

 [coeff, score, latent, tsquared, explained] = pca(mArray);
    coeffArray = coeff;

Answer 1

[Adam Danz]

From the documentation:

coeff = pca(X) returns the principal component coefficients, also known as loadings, for the n-by-p data matrix X. Rows of X correspond to observations and columns correspond to variables. The coefficient matrix is p-by-p.

In your case, your data are 20*7 and the output is 7*7 as expected.

If you were expecting 20 coefficients, transpose the input.

[. . .] = pca(mArray.');

See the link above for a detailed explanation of the output and several examples.