Action: STATS

Module	function
Description	Usage
Calculates statistical properties of a set of collective variables with respect to a set of reference values.

Details and examples

Calculates statistical properties of a set of collective variables with respect to a set of reference values.

In particular it calculates and stores as components the sum of the squared deviations, the correlation, the slope and the intercept of a linear fit.

The reference values can be either provided as values using PARAMETERS or using value without derivatives from other actions using PARARG (for example using experimental values from collective variables such as CS2BACKBONE, RDC, NOE, PRE).

Examples

The following input tells plumed to print the distance between three couple of atoms and compare them with three reference distances.

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

d1The DISTANCE action with label d1 calculates the following quantities:
 Quantity   
 Type   
 Description  
d1
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=10,50
d2The DISTANCE action with label d2 calculates the following quantities:
 Quantity   
 Type   
 Description  
d2
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=1,100
d3The DISTANCE action with label d3 calculates the following quantities:
 Quantity   
 Type   
 Description  
d3
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=45,75
stThe STATS action with label st calculates the following quantities:
 Quantity   
 Type   
 Description  
st.sqdevsum
scalar
the sum of the squared deviations between arguments and parameters
st.corr
scalar
the correlation between arguments and parameters
st.slope
scalar
the slope of a linear fit between arguments and parameters
st.intercept
scalar
the intercept of a linear fit between arguments and parameters: STATSCalculates statistical properties of a set of collective variables with respect to a set of reference values. More details ARGthe labels of the values from which the function is calculated=d1,d2,d3 PARAMETERSthe parameters of the arguments in your function=1.5,4.0,2.0
PRINTPrint quantities to a file. More details ARGthe labels of the values that you would like to print to the file=d1,d2,d3,st.*

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
PARARG	scalar	the input for this action is the scalar output from one or more other actions without derivatives

Output components

This action can calculate the values in the following table when the associated keyword is included in the input for the action. These values can be referenced elsewhere in the input by using this Action's label followed by a dot and the name of the value required from the list below.

Name	Type	Keyword	Description
sqdevsum	scalar	default	the sum of the squared deviations between arguments and parameters
corr	scalar	default	the correlation between arguments and parameters
slope	scalar	default	the slope of a linear fit between arguments and parameters
intercept	scalar	default	the intercept of a linear fit between arguments and parameters
sqd	scalar	SQDEV	the squared deviations between arguments and parameters

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
PARARGThis keyword do not have examples	input	none	the input for this action is the scalar output from one or more other actions without derivatives
NUMERICAL_DERIVATIVESThis keyword do not have examples	optional	false	calculate the derivatives for these quantities numerically
PARAMETERS	optional	not used	the parameters of the arguments in your function
SQDEVSUMThis keyword do not have examples	optional	false	calculates only SQDEVSUM
SQDEVThis keyword do not have examples	optional	false	calculates and store the SQDEV as components
UPPERDISTSThis keyword do not have examples	optional	false	calculates and store the SQDEV as components