DataGridView symmetric values for the main diagonal ?

Hello,

I'm using the DataGridView for an adjacency matrix, so I need the values left and right the main diagonal to be symmetric( or only left/right values)

If I've understood right, there is a method in C# that makes the values symmetric automatically ? If someone knows it, please tell it , it would be helpful.

If not, any useful algorithms for setting values left/right of the main diagonal for DataGridView ?


And the extra quoestion - any ideas how to use the values of DataGridView for drawing the unoriented graph ?