This function has been superseded by the much more versatile
transform.scdf function.
Shifting the values might be helpful in cases where the measurement time
is given as a time variable (see example below).
Arguments
- data
 A single-case data frame. See
scdf()to learn about this format.- value
 Number by which to shift the values
- var
 Character string with the name of the target variable. Defaults to the measurement time variable.
See also
Other data manipulation functions:
add_l2(),
as.data.frame.scdf(),
as_scdf(),
fill_missing(),
moving_median(),
outlier(),
ranks(),
rescale(),
scdf(),
select_cases(),
set_vars(),
smooth_cases(),
standardize(),
truncate_phase()
Examples
### Shift the measurement time for a better estimation of the intercept
ex <- shift(example_A24, value = -1996)
#> Warning: This function is deprecated. It might be dropped without any further notice in a future update of scan.
#> Please use function 'transform' instead of 'shift'.
plm(ex)
#> Piecewise Regression Analysis
#> 
#> Contrast model: W / level = first, slope = first
#> 
#> Fitted a gaussian distribution.
#> F(3, 19) = 46.74; p = 0.000; R² = 0.881; Adjusted R² = 0.862; AIC = 221.5733
#> 
#>                               B LL-CI95% UL-CI95%     SE      t     p delta R²
#> Intercept               258.714  223.364  294.065 18.036 14.344 0.000         
#> Trend (year)              1.857   -7.947   11.662  5.002  0.371 0.715    0.001
#> Level phase B (phaseB) -150.383 -200.743 -100.024 25.694 -5.853 0.000    0.215
#> Slope phase B (interB)   -1.726  -11.926    8.474  5.204 -0.332 0.744    0.001
#> 
#> Autocorrelations of the residuals
#>  lag    cr
#>    1  0.10
#>    2 -0.13
#>    3 -0.10
#> Ljung-Box test: X²(3) = 0.99; p = 0.804 
#> 
#> Formula: injuries ~ 1 + year + phaseB + interB 
# Please use transform instead:
example_A24 |>
  transform(year = year - 1996) |>
  plm()
#> Piecewise Regression Analysis
#> 
#> Contrast model: W / level = first, slope = first
#> 
#> Fitted a gaussian distribution.
#> F(3, 19) = 46.74; p = 0.000; R² = 0.881; Adjusted R² = 0.862; AIC = 221.5733
#> 
#>                               B LL-CI95% UL-CI95%     SE      t     p delta R²
#> Intercept               258.714  223.364  294.065 18.036 14.344 0.000         
#> Trend (year)              1.857   -7.947   11.662  5.002  0.371 0.715    0.001
#> Level phase B (phaseB) -150.383 -200.743 -100.024 25.694 -5.853 0.000    0.215
#> Slope phase B (interB)   -1.726  -11.926    8.474  5.204 -0.332 0.744    0.001
#> 
#> Autocorrelations of the residuals
#>  lag    cr
#>    1  0.10
#>    2 -0.13
#>    3 -0.10
#> Ljung-Box test: X²(3) = 0.99; p = 0.804 
#> 
#> Formula: injuries ~ 1 + year + phaseB + interB 
