Action: SELECT

Module	isdb
Description	Usage
Selects an argument based on the value of a SELECTOR.
output value	type
the value of the selected argument	scalar

Details and examples

Selects an argument based on the value of a SELECTOR.

You should read the documentation for SELECTOR to understand this action better.

Examples

In this example we use a simulated-tempering like approach activated by the RESCALE action. For each value of the scale parameter, we perform an independent Parallel Bias Metadynamics simulation (see PBMETAD). At each moment of the simulation, only one of the PBMETAD actions is activated, based on the current value of the associated SELECTOR. The SELECT action can then be used to print out the value of the (active) PBMETAD bias potential.

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

eneThe ENERGY action with label ene calculates the following quantities:
 Quantity   
 Type   
 Description  
ene
scalar
the internal energy:  ENERGYCalculate the total potential energy of the simulation box. More details
dThe DISTANCE action with label d calculates the following quantities:
 Quantity   
 Type   
 Description  
d
scalar
the DISTANCE between this pair of atoms: DISTANCECalculate the distance/s between pairs of atoms. More details ATOMSthe pair of atom that we are calculating the distance between=1,2

SELECTORDefines a variable (of the type double) inside the PLUMED code that can be used and modified by other actions. More details NAMEname of the SELECTOR=GAMMA VALUEset (initial) value of the SELECTOR=0

The SELECTOR action with label  calculates somethingpbmetad0The PBMETAD action with label pbmetad0 calculates the following quantities:
 Quantity   
 Type   
 Description  
pbmetad0.bias
scalar
the instantaneous value of the bias potential: PBMETADUsed to performed Parallel Bias metadynamics. More details ARGthe labels of the scalars on which the bias will act=d SELECTORadd forces and do update based on the value of SELECTOR=GAMMA SELECTOR_IDvalue of SELECTOR=0 SIGMAthe widths of the Gaussian hills=0.1 PACEthe frequency for hill addition, one for all biases=500 HEIGHTthe height of the Gaussian hills, one for all biases=1 BIASFACTORuse well tempered metadynamics with this bias factor, one for all biases=8 FILEfiles in which the lists of added hills are stored, default names are assigned using arguments if FILE is not found=HILLS.0
pbmetad1The PBMETAD action with label pbmetad1 calculates the following quantities:
 Quantity   
 Type   
 Description  
pbmetad1.bias
scalar
the instantaneous value of the bias potential: PBMETADUsed to performed Parallel Bias metadynamics. More details ARGthe labels of the scalars on which the bias will act=d SELECTORadd forces and do update based on the value of SELECTOR=GAMMA SELECTOR_IDvalue of SELECTOR=1 SIGMAthe widths of the Gaussian hills=0.1 PACEthe frequency for hill addition, one for all biases=500 HEIGHTthe height of the Gaussian hills, one for all biases=1 BIASFACTORuse well tempered metadynamics with this bias factor, one for all biases=8 FILEfiles in which the lists of added hills are stored, default names are assigned using arguments if FILE is not found=HILLS.1

RESCALEScales the value of an another action, being a Collective Variable or a Bias. More details ...
LABELa label for the action so that its output can be referenced in the input to other actions=resThe RESCALE action with label res calculates the following quantities:
 Quantity   
 Type   
 Description  
res.bias
scalar
the instantaneous value of the bias potential
res.igamma
scalar
gamma parameter
res.accgamma
scalar
MC acceptance for gamma
res.wtbias
scalar
well-tempered bias ARGthe labels of the scalars on which the bias will act=ene,pbmetad0.bias,pbmetad1.bias TEMPtemperature=300
SELECTORname of the SELECTOR used for rescaling=GAMMA MAX_RESCALEmaximum values for rescaling=1.2 NOT_RESCALEDthese last N arguments will not be scaled=2 NBINnumber of bins for gamma grid=2
W0initial bias height=1000 BIASFACTORbias factor=100.0 BSTRIDEstride for writing bias=2000 BFILEfile name for bias=bias.dat
...

pbactiveThe SELECT action with label pbactive calculates the following quantities:
 Quantity   
 Type   
 Description  
pbactive
scalar
the value of the selected argument: SELECTSelects an argument based on the value of a SELECTOR. More details ARGthe labels of the values from which the function is calculated=pbmetad0.bias,pbmetad1.bias SELECTORname of the variable used to select=GAMMA

PRINTPrint quantities to a file. More details ARGthe labels of the values that you would like to print to the file=pbactive STRIDE the frequency with which the quantities of interest should be output=100 FILEthe name of the file on which to output these quantities=COLVAR

Input

The arguments that serve as the input for this action are specified using one or more of the keywords in the following table.

Keyword	Type	Description
ARG	scalar	the labels of the values from which the function is calculated

Full list of keywords

The following table describes the keywords and options that can be used with this action

Keyword	Type	Default	Description
ARG	input	none	the labels of the values from which the function is calculated
SELECTOR	compulsory	none	name of the variable used to select
NUMERICAL_DERIVATIVESThis keyword do not have examples	optional	false	calculate the derivatives for these quantities numerically