code: public T invert() {
          T ret = createLike();
  
          if( !ops.invert(mat,ret.mat))
              throw new SingularMatrixException();
          if( ops.hasUncountable(ret.mat))
              throw new SingularMatrixException("Solution contains uncountable numbers");
  
          return ret;
      }
docs: <p>
  Returns the inverse of this matrix.<br>
  <br>
  b = a<sup>-1</sup><br>
  </p>
  
  <p>
  If the matrix could not be inverted then SingularMatrixException is thrown.  Even
  if no exception is thrown the matrix could still be singular or nearly singular.
  </p>
  
  @see CommonOps_DDRM#invert(DMatrixRMaj, DMatrixRMaj)
  
  @throws SingularMatrixException
  
  @return The inverse of this matrix.