Gershgorin Circle

Let $A$ be a real or complex $n\times n$ matrix, this application determines the radius \[ R_i = \left\{ \begin{array}{ll} \displaystyle \min\left(\sum_{j=1,j\ne i}^n|a_{ij}|,\sum_{k=1,k\ne i}^n|a_{ki}| \right) & \text{for real matrix} \\ \displaystyle \sum_{j=1,j\ne i}^n|a_{ij}| & \text{for complex matrix} \end{array} \right. \] of the circle with center at $a_{ii}$, the diagonal entries of $A$.