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FitCurves

Source: R/analyze.R
FitCurves.Rd

Analyzes purchase task data

Usage

FitCurves(
  dat,
  equation,
  k,
  agg = NULL,
  detailed = FALSE,
  xcol = "x",
  ycol = "y",
  idcol = "id",
  groupcol = NULL,
  lobound,
  hibound,
  constrainq0 = NULL,
  startq0 = NULL,
  startalpha = NULL,
  param_space = c("natural", "log10")
)

Arguments

dat

data frame (long form) of purchase task data.

equation

Character vector of length one. Accepts either "hs" for Hursh and Silberberg (2008) or "koff" for Koffarnus, Franck, Stein, and Bickel (2015).

k

A numeric (or character) vector of length one. Reflects the range of consumption in log10 units. If none provided, k will be calculated based on the max/min of the entire sample + .5. If k = "ind", k will be calculated per individual using max/min + .5. If k = "fit", k will be a free parameter on an individual basis. If k = "range", k will be calculated based on the max/min of the entire sample + .5.

agg

Character vector of length one accepts either "Mean" or "Pooled". If not NULL (default), data will be aggregrated appropriately and analyzed in the specified way.

detailed

If TRUE, output will be a 3 element list including (1) dataframe of results, (2) list of model objects, (3) list of individual dataframes used in fitting. Default value is FALSE, which returns only the dataframe of results.

xcol

The column name that should be treated as "x" data

ycol

The column name that should be treated as "y" data

idcol

The column name that should be treated as dataset identifier

groupcol

The column name that should be treated as the groups

lobound

Optional. A named vector of length 2 ("q0", "alpha") or 3 ("q0", "k", "alpha"), the latter length if k = "fit", specifying the lower bounds.

hibound

Optional. A named vector of length 2 ("q0", "alpha") or 3 ("q0", "k", "alpha"), the latter length if k = "fit", specifying the upper bounds.

constrainq0

Optional. A number that will be used to constrain Q0 in the fitting process. Currently experimental and only works with a fixed k value.

startq0

Optional. A number that will be used to start Q0 in the fitting process. Currently experimental.

startalpha

Optional. A number that will be used to start Alpha in the fitting process. Currently experimental.

param_space

Character. One of "natural" (default) or "log10". Specifies whether parameters (Q0, alpha) are estimated in natural space or log10-transformed space.

Value

If detailed == FALSE (default), a dataframe of results. If detailed == TRUE, a 3 element list consisting of (1) dataframe of results, (2) list of model objects, (3) list of individual dataframes used in fitting

Details

[Superseded]

FitCurves() has been superseded by fit_demand_fixed(), which provides a modern S3 interface with standardized methods (summary(), tidy(), glance(), predict()). FitCurves() will continue to work but is no longer recommended for new code. See vignette("migration-guide") for migration instructions.

See also

fit_demand_fixed() for the modern interface

Author

Brent Kaplan bkaplan.ku@gmail.com Shawn Gilroy shawn.gilroy@temple.edu

Examples

## Analyze using Hursh & Silberberg, 2008 equation with a k fixed to 2
FitCurves(apt[sample(apt$id, 5), ], "hs", k = 2)
#> Warning: `FitCurves()` was deprecated in beezdemand 0.2.0.
#> ℹ Please use `fit_demand_fixed()` instead.
#> ℹ FitCurves() returns raw data frames; fit_demand_fixed() returns a
#>   structured S3 object with summary(), tidy(), glance(), and predict().
#> ℹ See vignette('migration-guide') for migration instructions.
#> Error in GetEmpirical(dat): Duplicates found where id = 68. Check data and rerun.