constraint on basis matrix constraint pca r constrains in ppca can you use nonnegative constrains in r why does r use non negative constrain r constrain constraint on basis how are constrains applied in pca why do we use nonnegative constrains in coordinate matrix can you apply constrains in the basis matrix in r constraint constraint constraint constraint why use nonnegative constrains constraint of pca which constraint can be applied to a pca? what is non-negative pca constraint constrain pca sparse constrain pca in r what constraint is applied to sparse pca when constraining a sparse pca constraint on sparse pca what constraint is applied on the basis matrix