A method of enabling a selection of one or more transactions from a plurality of transactions, the method comprising: determining a hierarchy having a tree structure wherein leaf nodes in the lowest level of the hierarchy correspond to sources and destinations associated with transactions; associating elements of the hierarchy with co-ordinates on a display screen; representing each of the plurality of transactions on the display by: determining for each transaction a first set of control co-ordinates comprising the co-ordinates associated with elements in a path in the tree structure connecting the source and destination associated with a transaction via the closest common parent in the hierarchy common to the source and destination; determining for each transaction a second set of control co-ordinates for drawing a straight line between co-ordinates associated with the source and destination associated with the transaction; calculating as a set of control co-ordinates for representing a transaction weighted averages of corresponding co-ordinates in the first and second set, weighted by a bundling factor; and representing each of the transactions as a line drawn utilizing the calculated control co-ordinates for each transaction; utilizing the drawing of a selection line on the display by a user to identify an angle of the selection line; re-rendering a representation of the display within a graphics buffer without updating the display, wherein the re-rendering applies a rotation to the display based on the angle of the selection line such that the selection line corresponds to a row or column of pixels; and identifying transactions for which the line representing the transaction intersects with the selection line in the re-rendered representation of the display within the graphics buffer by identifying transactions for which the line representing the transaction has a pixel in common with the selection line. determining a hierarchy having a tree structure wherein leaf nodes in the lowest level of the hierarchy correspond to sources and destinations associated with transactions; associating elements of the hierarchy with co-ordinates on a display screen; representing each of the plurality of transactions on the display by: determining for each transaction a first set of control co-ordinates comprising the co-ordinates associated with elements in a path in the tree structure connecting the source and destination associated with a transaction via the closest common parent in the hierarchy common to the source and destination; determining for each transaction a second set of control co-ordinates for drawing a straight line between co-ordinates associated with the source and destination associated with the transaction; calculating as a set of control co-ordinates for representing a transaction weighted averages of corresponding co-ordinates in the first and second set, weighted by a bundling factor; and representing each of the transactions as a line drawn utilizing the calculated control co-ordinates for each transaction; determining for each transaction a first set of control co-ordinates comprising the co-ordinates associated with elements in a path in the tree structure connecting the source and destination associated with a transaction via the closest common parent in the hierarchy common to the source and destination; determining for each transaction a second set of control co-ordinates for drawing a straight line between co-ordinates associated with the source and destination associated with the transaction; calculating as a set of control co-ordinates for representing a transaction weighted averages of corresponding co-ordinates in the first and second set, weighted by a bundling factor; and representing each of the transactions as a line drawn utilizing the calculated control co-ordinates for each transaction; utilizing the drawing of a selection line on the display by a user to identify an angle of the selection line; re-rendering a representation of the display within a graphics buffer without updating the display, wherein the re-rendering applies a rotation to the display based on the angle of the selection line such that the selection line corresponds to a row or column of pixels; and identifying transactions for which the line representing the transaction intersects with the selection line in the re-rendered representation of the display within the graphics buffer by identifying transactions for which the line representing the transaction has a pixel in common with the selection line.