code: public static double normP(DMatrixRMaj A , double p ) {
          if( p == 1 ) {
              return normP1(A);
          } else if( p == 2 ) {
              return normP2(A);
          } else if( Double.isInfinite(p)) {
              return normPInf(A);
          }
          if( MatrixFeatures_DDRM.isVector(A) ) {
              return elementP(A,p);
          } else {
              throw new IllegalArgumentException("Doesn't support induced norms yet.");
          }
      }
docs: Computes either the vector p-norm or the induced matrix p-norm depending on A
  being a vector or a matrix respectively.
  
  @param A Vector or matrix whose norm is to be computed.
  @param p The p value of the p-norm.
  @return The computed norm.