docs: public double response( double[] sample ) {
          if( sample.length != A.numCols )
              throw new IllegalArgumentException("Expected input vector to be in sample space");
  
          DMatrixRMaj dots = new DMatrixRMaj(numComponents,1);
          DMatrixRMaj s = DMatrixRMaj.wrap(A.numCols,1,sample);
  
          CommonOps_DDRM.mult(V_t,s,dots);
  
          return NormOps_DDRM.normF(dots);
      }