7.3.coldstart.code {pems.utils}

Cold Start Emissions related code

Description

Functions associated with Cold Start Emissions calculations.

Usage

#calculations

fitColdStart(em, time, engine.on = NULL, 
             data = NULL, method = 2, ...,
             fun.name="fitColdStart")

#Cold Start Plots

coldStartPlot(time, em = NULL,  
             ..., data = NULL, engine.on = NULL,
             plot.type = 1, method = 2,
             fun.name="coldStartPlot",
             scheme = pems.scheme)

panel.coldStartPlot1(..., loa.settings = FALSE)
panel.coldStartPlot2(..., loa.settings = FALSE)

Arguments

em, time

(Typically pems.element vectors) em is the emissions data-series that the cold start contribution should be estimated for; time is the associated time-series, typically a local time measurement in seconds.

engine.on

(Optimal, single Numeric) The time the emission source, e.g. monitored vehicle engine, was started. If not supplied, this is assumed to be start of the supplied em and time data-series. See also Notes.

data

(Optional, typically pems) The data source for em and time.

method

(Optinal, Numeric) The method to use when fitting and calculating the cold start contribution: method 1 Single break point fit of accumulated emissions; method 2 modified break-point. If not supplied, method 2 is used by default.See also Notes and References.

...

(Optional) Other arguments, currently passed on as supplied to assoicated calculation or plotting function.

fun.name

(Optional character) The name of the parent function, to be used in error messaging.

plot.type

(Optional numeric) For coldStartPlot, the type of cold start plot to generate: 1 a conventional accumulation profile; or 2 an emission time-series. If not supplied, plot type 1 is selected by default.

scheme

(Various) For coldStartPlot, the scheme to apply to the plot, loa argument.

loa.settings

(Logical) For coldStartPlot panel functions, a loa plot argument that can typically be ignored by plot users.

Details

fitColdStart fits a cold start model to the supplied emissions and time-series data.

coldStartPlot generates a plot of the cold start model.

panel.coldStartPlot1 and panel.coldStartPlot1 are plot panels used by coldStartPlot when generating plot.types 1 and 2, respectively.

Value

fitColdStart generates a cold start contribution report as a pems dataset.

coldStartPlot generates a cold start contribution report as a lattice plot.

Note

Regarding engine.on: This is specifically the time the engine is turned on rather than the row of data set where this happens. In some cases, they are same, e.g. when the data is logged at a regular 1-Hz and data capture is complete.

Regarding method: Method 1 (break-point) and method 2 (modified break-point) are based on the identification of a change point in the accumulated emissions profile.

[Doc further]

(See References.)

Author(s)

Karl Ropkins

References

fitColdStart uses methods described in:

[Heeb]

[Ropkins cold start]

See Also

See common.calculations (and checkUnits and convertUnits) for details of data management.

Examples

###########
##example 1 
###########

#basic usage

#to do/maybe not run... time to compile...