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Short helpfile for action ANGLES
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The input trajectory can be in any of the following formats: 

                  GROUP - Calculate angles for each distinct set of three atoms in 
                          the group 
                 GROUPA - A group of central atoms about which angles should be 
                          calculated 
                 GROUPB - When used in conjunction with GROUPA this keyword instructs 
                          plumed to calculate all distinct angles involving one atom from 
                          GROUPA and two atoms from GROUPB. The atom from GROUPA is the 
                          central atom. 
                 GROUPC - This must be used in conjunction with GROUPA and GROUPB. 
                          All angles involving one atom from GROUPA, one atom from GROUPB 
                          and one atom from GROUPC are calculated. The GROUPA atoms are 
                          assumed to be the central atoms 

The following options are available

                HIGHEST - ( default=off ) this flag allows you to recover the highest 
                          of these variables. 
                 LOWEST - ( default=off ) this flag allows you to recover the lowest 
                          of these variables. 
                    SUM - ( default=off ) calculate the sum of all the quantities. 
                   MEAN - ( default=off ) calculate the mean of all the quantities. 
                 SWITCH - the switching function specifies that only those bonds that 
                          have a length that is less than a certain threshold are 
                          considered 
              LESS_THAN - calculate the number of variables that are less than a 
                          certain target value. 
              MORE_THAN - calculate the number of variables that are more than a 
                          certain target value. 
                ALT_MIN - calculate the minimum value. 
                    MIN - calculate the minimum value. 
                    MAX - calculate the maximum value. 
                BETWEEN - calculate the number of values that are within a certain 
                          range. These quantities are calculated using kernel density 
                          estimation as described on \ref histogrambead.. You can use multiple 
                          instances of this keyword i.e. BETWEEN1, BETWEEN2, BETWEEN3... 
              HISTOGRAM - calculate a discretized histogram of the distribution of 
                          values. This shortcut allows you to calculates NBIN quantites like 
                          BETWEEN. 


