#### Every

The every keyword has special meaning when used with matrix data. Rather than applying to blocks of single points, it applies to rows and column values. Note that matrix rows and columns are indexed starting from 0, so the row with index N is the (N+1)th row. Syntax:

         plot 'file' every {<column_incr>}
                             {:{<row_incr>}
                               {:{<start_column>}
                                 {:{<start_row>}
                                   {:{<end_column>}
                                     {:<end_row>}}}}}

Examples:

         plot 'file' matrix every :::N::N   # plot all values in row with index N
         plot 'file' matrix every ::3::7    # plot columns 3 to 7 for all rows
         plot 'file' matrix every ::3:0:7:4 # submatrix bounded by [3,0] and [7,4]