metRology (version 0.9-28-1)

update.uncert: Update and recalculate an uncertainty estimate

Description

‘update’ allows modification of components of ‘uncert’ or ‘uncertMC’ objects, including the uncertainty estimation method used, and will recalculate the estimate and return a new ‘uncert’ or ‘uncertMC’ object. Individual elements of most components can be amended.

Usage

# S3 method for uncert
update(object, expr = NULL, method = NULL, x = NULL, u = NULL, c=NULL, 
		df = NULL, cov = NULL, cor = NULL, distrib = NULL, 
		distrib.pars = NULL, delta = NULL, B = NULL, keep.x = NULL, ...)

Arguments

object

An object of class ‘uncert’

expr

An expression, formula or function.

method

Uncertainty evaluation method. May be any of the methods listed for uncert.

x, u, df

Named list, vector or array of values to update elements of object uncert. See Details for options.

c

Update to uncert$budget$c No effect except for updates using uncert.default.

cov, cor

A covariance or correlation matrix. Only one of u and cov should be specified; if both are specified, cov will take precedence and a warning will be issued.

distrib

Named list or character vector of updated distribution names.

distrib.pars

Named list of updates for distribution names and parameters.

delta

Scalar value updating delta for numeric evaluation methods.

B

Updated number of Monte Carlo iterations for ‘uncertMC’ objects or specification of B when updating ‘uncertMC’ objects using method="MC".

keep.x

Update to keep.x passed to uncertMC for Monte Carlo updates.

…

Other values passed to uncert or uncertMC

Value

An object of class ‘uncert’ or, for method="MC" of class ‘uncertMC’. See uncert-class and uncertMC-class for details.

Details

Update will use the values provided to update the object given, call the original function with the revised parameters and return the result as an object of class ‘uncert’ or ‘uncert’ depending on the uncertainty evaluation method used.

Note that updating with a different value of method may result in an object of different class. Updating an ‘uncertMC’ object with a method other than "MC" will return an object of class ‘uncert’; similarly, updating an ‘uncert’ object using method="MC" will return an object of class ‘uncertMC’.

Updates to vector or list elements of uncert such as x, u, df etc. can be specified as named lists, named vectors or arrays, with names corresponding to names of the input quantities in the uncertainty budget (that is, the names may correspond to one or more of row.names(uncert$budget)). If names are present, only the corresponding individual members are updated. If names are not present, the complete vector or list in uncert is replaced, and names added.

Matrix elements cor and cov must be specified completely; see buildCor, updateCor and associated functions for covariance matrices for compact update methods.

References

None, yet.

See Also

uncert-class, uncert-class, uncertMC, uncertMC-class

Examples

# NOT RUN {
  #From uncert:
  expr <- expression(a+b*2+c*3+d/2)
  x <- list(a=1, b=3, c=2, d=11)
  u <- lapply(x, function(x) x/10)
  u.expr<-uncert(expr, x, u, method="NUM")
  u.expr

  update(u.expr, u=list(a=0.3))
  
  update(u.expr, method="MC")
  
# }