Calculate strictly standardized mean difference (SSMD)

Usage

calculateSSMD(res, internal = TRUE, nConc = 2)

Arguments

res: Object of class MALDIassay
internal: Logical, currently only the internal implementation, using nConc top and bottom concentrations, is implemented.
nConc: Numeric, number of top and bottom concentrations to be used to calculate the pseudo positive and negative control. Only used if internal is TRUE

Value

Numeric vector of strictly standardized mean differences (SSMD)

Details

The strictly standardized mean difference (SSMD) is a measure of effect size. It is the mean divided by the standard deviation of a difference between the positive and negative control.

$$\gamma=\frac{\mid\mu_n - \mu_p\mid}{\sqrt{\sigma_n^2 + \sigma_p^2}}$$

The SSMD can be easily be interpreted as it denotes the difference between positve and negative controls in units of standard deviation.

Examples

# see example for `fitCurve()` to see how this data was generated
data(Blank2022res)

calculateSSMD(Blank2022res, nConc = 2)       
#>  [1] 0.9929269 1.8295971 0.4589847 0.5734228 1.2892462 1.7888130 3.1918283
#>  [8] 1.8648946 1.6817642 1.6596281 1.6481736 1.2971227 4.0481543 2.3039603
#> [15] 2.4210874 3.8748702 3.8690381 3.9669764 5.0425580 4.6732764 4.3425562
#> [22] 4.3308703 3.6642894