LOAD

This is part of the setup module

Loads a library, possibly defining new actions.

It is available only on systems allowing for dynamic loading. It can also be fed with a cpp file, in which case the file is compiled first.

Examples

If you have a shared object named extensions.so and want to use the functions implemented within it within PLUMED you can load it with the following syntax

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

LOAD 
FILE
compulsory keyword 
file to be loaded 
=extensions.so  You cannot view the components that are calculated by each action for this input file. Sorry 

As a more practical example, imagine that you want to make a small change to one collective variable that is already implemented in PLUMED, say DISTANCE . Copy the file src/colvar/Distance.cpp into your work directory, rename it as Distance2.cpp and edit it as you wish. It might be better to also replace any occurrence of the string DISTANCE within the file with DISTANCE2, so that both old and new implementation will be available with different names. Then you can compile it into a shared object using

> plumed mklib Distance2.cpp

This will generate a file Distance2.so (or Distance2.dylib on a mac) that can be loaded. Now you can use your new implementation with the following input

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

# load the new library
LOAD 
FILE
compulsory keyword 
file to be loaded 
=Distance2.so  You cannot view the components that are calculated by each action for this input file. Sorry 
# compute standard distance
d: DISTANCE 
ATOMS
the pair of atom that we are calculating the distance between. 
=1,10  You cannot view the components that are calculated by each action for this input file. Sorry 
# compute modified distance
d2: DISTANCE2 
ATOMS
 could not find this keyword 
=1,10  You cannot view the components that are calculated by each action for this input file. Sorry 
# print them on a file
PRINT 
ARG
the input for this action is the scalar output from one or more other actions. 
=d,d2 
FILE
the name of the file on which to output these quantities 
=compare-them  You cannot view the components that are calculated by each action for this input file. Sorry 

You can even skip the initial step and directly feed PLUMED with the Distance2.cpp file: it will be compiled on the fly.

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

# load the new definition
# this is a cpp file so it will be compiled
LOAD 
FILE
compulsory keyword 
file to be loaded 
=Distance2.cpp  You cannot view the components that are calculated by each action for this input file. Sorry 
# compute standard distance
d: DISTANCE 
ATOMS
the pair of atom that we are calculating the distance between. 
=1,10  You cannot view the components that are calculated by each action for this input file. Sorry 
# compute modified distance
d2: DISTANCE2 
ATOMS
 could not find this keyword 
=1,10  You cannot view the components that are calculated by each action for this input file. Sorry 
# print them on a file
PRINT 
ARG
the input for this action is the scalar output from one or more other actions. 
=d,d2 
FILE
the name of the file on which to output these quantities 
=compare-them  You cannot view the components that are calculated by each action for this input file. Sorry 

This will allow to make quick tests while developing your own variables. Of course, after your implementation is ready you might want to add it to the PLUMED source tree and recompile the whole PLUMED.

Glossary of keywords and components

Compulsory keywords

FILE	file to be loaded