	This is part of the ves module
	It is only available if you configure PLUMED with ./configure –enable-modules=ves . Furthermore, this feature is still being developed so take care when using it and report any problems on the mailing list.

Output basis functions to file.

This action can be used to write out to a grid file the values and derivatives of given basis functions. This is normally used for debugging when programming new types of basis functions. For example, it is possible to calculate the derivatives numerically and compare to the analytically calculated derivatives.

This action is normally used through the driver.

Examples

In the following input we define a Legendre polynomials basis functions of order 14 over the interval -4.0 to 4.0 and output their values and derivatives to files called bfL.values.data and bfL.derivs.data.

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

bfL: BF_LEGENDRE ...
   ORDERcompulsory keyword 
The order of the basis function expansion. =14 
   MINIMUMcompulsory keyword 
The minimum of the interval on which the basis functions are defined. =-4.0 
   MAXIMUMcompulsory keyword 
The maximum of the interval on which the basis functions are defined. =4.0 
   
...The BF_LEGENDRE action with label bfL
VES_OUTPUT_BASISFUNCTIONS ...
   BASIS_FUNCTIONScompulsory keyword 
the label of the basis functions that you want to use 
=bfL 
   GRID_BINSthe number of bins used for the grid for writing the basis function values and derivatives.
=200 
   FORMAT_VALUES_DERIVSthe numerical format of the basis function values and derivatives written to file.
=%13.6f 
...The VES_OUTPUT_BASISFUNCTIONS action with label

This input should be run through the driver by using a command similar to the following one where the trajectory/configuration file configuration.gro is needed to trick the code to exit correctly.

plumed driver --plumed plumed.dat --igro configuration.gro

Glossary of keywords and components

Compulsory keywords

BASIS_FUNCTIONS

the label of the basis functions that you want to use

Options

IGNORE_PERIODICITY	( default=off ) if the periodicity of the basis functions should be ignored.
NUMERICAL_DERIVATIVES	( default=off ) if the derivatives of the basis functions should be calculated numerically.
GRID_BINS	the number of bins used for the grid for writing the basis function values and derivatives. The default value is 1000.
GRID_MIN	the minimum of the grid for writing the basis function values and derivatives. By default it is the minimum of the interval on which the basis functions are defined.
GRID_MAX	the maximum of the grid for writing the basis function values and derivatives. By default it is the maximum of the interval on which the basis functions are defined.
FILE_VALUES	filename of the file on which the basis function values are written. By default it is BF_LABEL.values.data.
FILE_DERIVS	filename of the file on which the basis function derivatives are written. By default it is BF_LABEL.derivs.data.
FORMAT_VALUES_DERIVS	the numerical format of the basis function values and derivatives written to file. By default it is %15.8f. . You can also use FORMAT_VALUES and FORMAT_DERIVS to give the numerical formats separately.
FORMAT_VALUES	the numerical format of the basis function derivatives written to file. By default it is %15.8f.
FORMAT_DERIVS	the numerical format of the basis function values written to file. By default it is %15.8f.
FILE_TARGETDIST_AVERAGES	filename of the file on which the averages over the target distributions are written. By default it is BF_LABEL.targetdist-averages.data.
FORMAT_TARGETDIST_AVERAGES	the numerical format of the target distribution averages written to file. By default it is %15.8f.
FILE_TARGETDIST	filename of the files on which the target distributions are written. By default it is BF_LABEL.targetdist-#.data.
TARGET_DISTRIBUTION	the target distribution to be used. You can use multiple instances of this keyword i.e. TARGET_DISTRIBUTION1, TARGET_DISTRIBUTION2, TARGET_DISTRIBUTION3...