Reverse Cuthill-McKee method

Once the Cuthill-McKee method has been applied, the procedure for the Reverse Cuthill-McKee method is simple all that needs to be done is to apply the Reverse function to the previous vector. 

This may be important to do since the Reverse Cuthill-McKee method is sometimes more effective (Saad, 2003) than the original, usually when one or more columns and one or more rows of the original matrix are dense. 

When ordering must be carried out automatically, two very widely used techniques for symmetric positive definite matrices are CuthiU-McKee Ordering and Reverse CuthiU-McKee Ordering. The Cuthill-McKee method is usually described by means of the graph theory (Saad, 2003). It is also possible to realize it by means of matrix algebra, as illustrated by the simple example below. 

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