CONSTANT

This is part of the colvar module

Return one or more constant quantities with or without derivatives.

Useful in combination with functions that takes in input constants or parameters.

Examples

The following input instructs plumed to compute the distance between atoms 1 and 2. If this distance is between 1.0 and 2.0, it is printed. If it is lower than 1.0 (larger than 2.0), 1.0 (2.0) is printed

Click on the labels of the actions for more information on what each action computes

cn: CONSTANT 
VALUES
The values of the constants 
=1.0,2.0 The CONSTANT action with label cn calculates the following quantities:

 Quantity   
 Description  
cn.v-0
the # value  This is the 0th of these quantities
cn.v-1
the # value  This is the 1th of these quantities


dis: DISTANCE 
ATOMS
the pair of atom that we are calculating the distance between. 
=1,2 The DISTANCE action with label dis calculates a single scalar value
sss: SORT 
ARG
the input for this action is the scalar output from one or more other actions. 
=cn.v-0,dis,cn.v-1 The SORT action with label sss calculates the following quantities:

 Quantity   
 Description  
sss.1
the label of this action is set by user in the input. See documentation above.
sss.2
the label of this action is set by user in the input. See documentation above.
sss.3
the label of this action is set by user in the input. See documentation above.


PRINT 
ARG
the input for this action is the scalar output from one or more other actions. 
=sss.2 The PRINT action with label 

In case you want to pass a single value you can use VALUE:

Click on the labels of the actions for more information on what each action computes

cn: CONSTANT 
VALUE
The value of the constant 
=1.0 The CONSTANT action with label cn calculates a single scalar value
dis: DISTANCE 
ATOMS
the pair of atom that we are calculating the distance between. 
=1,2 The DISTANCE action with label dis calculates a single scalar value
sss: SORT 
ARG
the input for this action is the scalar output from one or more other actions. 
=cn,dis The SORT action with label sss calculates the following quantities:

 Quantity   
 Description  
sss.1
the label of this action is set by user in the input. See documentation above.
sss.2
the label of this action is set by user in the input. See documentation above.


PRINT 
ARG
the input for this action is the scalar output from one or more other actions. 
=sss.1 The PRINT action with label 

Glossary of keywords and components

Description of components

By default this Action calculates the following quantities. These quantities can be referenced elsewhere in the input by using this Action's label followed by a dot and the name of the quantity required from the list below.

Quantity	Description
v	the # value

Options

NOPBC	( default=off ) ignore the periodic boundary conditions when calculating distances
NODERIV	( default=off ) Set to TRUE if you want values without derivatives.
VALUES	The values of the constants
VALUE	The value of the constant