what is the difference between pca(x) and princomp(x) matlab commands?

could any one help me the difference between pca(x) and princomp(x) matlab commands?

Answer 1

[Tom Lane]

If you type "type princomp" you will see that it is just a call to pca with certain default inputs defined. The pca function was introduced just in an attempt to have a more familiar name.

[Mohamed Moawed]

thanks for your reply. i want to ask is the input of the princomp is input matrix or covariance matrix? ans what about pca function is input matrix or covariance matrix?

[Tom Lane]

Use pcacov if you have the covariance matrix. The others expect the data matrix.

Answer 2

[Andrea Le]

Besides from what Tom said, I want to add other difference between these two commands princomp lets you decide to do an economic version of the outputs. pca automatically truncates your matrix into an economic version.

[Imad Ahmed Tungekar]

could you please elaborate what is economic version of the output?