code: def eval_basis(self, x, regularize=True):
          
          if regularize:
              x = regularize_array(x)
  
          out = zeros((self.n, x.shape[0]), dtype=float, order='F')
  
          for i in xrange(self.n):
              out[i] = self.basis[i](x, **self.params)
  
          return out
docs: basis_mat = C.eval_basis(x)
  
          Evaluates self's basis functions on x and returns them stacked
          in a matrix. basis_mat[i,j] gives basis function i evaluated at
          x[j,:].