Last data update: 2014.03.03
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R: Recalibrate x, y data using SITAR random effects
Recalibrate x, y data using SITAR random effects
Description
A function to recalibrate x,y data using SITAR random effects
Usage
recalib(xc, yc, id = NULL, data, xcnew = NULL, ycnew = NULL,
model, from, to)
Arguments
xc |
character vector defining column name(s) of x data to be recalibrated.
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yc |
character vector defining column name(s) of y data to be recalibrated.
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id |
factor defining from and to rows. If NULL then recalibrate all rows.
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data |
dataframe containing xc , yc and id .
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xcnew |
column names for replacement columns xc . If default NULL then use names xcnew1... .
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ycnew |
column names for replacement columns yc . If default NULL then use names ycnew1... .
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model |
sitar model defining the random effects to be used for recalibration.
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from |
level of id defining existing data (must be a single row in coef{model} ).
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to |
level of id defining data to be recalibrated (a single row in coef{model} ).
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Details
recalib recalibrates the values of xc and yc based on model .
xc values are changed to:
(xc-c(coef[from,'b']))*exp(coef[from,'c']-coef[to,'c'])+coef[to,'b'].
yc values are changed to:
yc-coef[from,'a']+coef[to,'a'] .
Value
Returns the dataframe data with the from rows of xc and yc recalibrated.
Author(s)
Tim Cole tim.cole@ucl.ac.uk
Results
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