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These functions can be used for generating random MIC values and disk diffusion diameters, for AMR data analysis practice. By providing a microorganism and antimicrobial drug, the generated results will reflect reality as much as possible.

Usage

random_mic(size = NULL, mo = NULL, ab = NULL, skew = "right",
  severity = 1, ...)

random_disk(size = NULL, mo = NULL, ab = NULL, skew = "left",
  severity = 1, ...)

random_sir(size = NULL, prob_SIR = c(0.33, 0.33, 0.33), ...)

Arguments

size

Desired size of the returned vector. If used in a data.frame call or dplyr verb, will get the current (group) size if left blank.

mo

Any character that can be coerced to a valid microorganism code with as.mo(). Can be the same length as size.

ab

Any character that can be coerced to a valid antimicrobial drug code with as.ab().

skew

Direction of skew for MIC or disk values, either "right" or "left". A left-skewed distribution has the majority of the data on the right.

severity

Skew severity; higher values will increase the skewedness. Default is 2; use 0 to prevent skewedness.

...

Ignored, only in place to allow future extensions.

prob_SIR

A vector of length 3: the probabilities for "S" (1st value), "I" (2nd value) and "R" (3rd value).

Value

class mic for random_mic() (see as.mic()) and class disk for random_disk() (see as.disk())

Details

Internally, MIC and disk zone values are sampled based on clinical breakpoints defined in the clinical_breakpoints data set. To create specific generated values per bug or drug, set the mo and/or ab argument. The MICs are sampled on a log2 scale and disks linearly, using weighted probabilities. The weights are based on the skew and severity arguments:

  • skew = "right" places more emphasis on lower MIC or higher disk values.

  • skew = "left" places more emphasis on higher MIC or lower disk values.

  • severity controls the exponential bias applied.

Examples

random_mic(25)
#> Class 'mic'
#>  [1] 0.125    2        16       1        0.004    0.008    0.0005   0.125   
#>  [9] 2        0.008    0.008    0.016    0.064    0.064    <=0.0002 0.001   
#> [17] 0.0005   0.5      0.002    0.002    0.125    8        <=0.0002 0.002   
#> [25] 0.064   
random_disk(25)
#> Class 'disk'
#>  [1] 47 24 47 38 28 36 33 31 50 41 29 40 31 44 45 37 40 44 49  9 48 20 37 47 28
random_sir(25)
#> Class 'sir'
#>  [1] S R R S S I S I S S I S R I I I I S I R I I I I R

# add more skewedness, make more realistic by setting a bug and/or drug:
disks <- random_disk(100, severity = 2, mo = "Escherichia coli", ab = "CIP")
plot(disks)

# `plot()` and `ggplot2::autoplot()` allow for coloured bars if `mo` and `ab` are set
plot(disks, mo = "Escherichia coli", ab = "CIP", guideline = "CLSI 2025")


# \donttest{
random_mic(25, "Klebsiella pneumoniae") # range 0.0625-64
#> Class 'mic'
#>  [1] 0.0005   8        0.008    0.0002   0.0002   0.0002   0.0002   <=0.0001
#>  [9] 64       <=0.0001 1        0.5      0.001    0.5      0.001    0.0005  
#> [17] 0.016    0.008    0.002    0.032    <=0.0001 0.0002   0.001    0.0005  
#> [25] 0.001   
random_mic(25, "Klebsiella pneumoniae", "meropenem") # range 0.0625-16
#> Class 'mic'
#>  [1] <=0.5 <=0.5 2     <=0.5 1     <=0.5 <=0.5 <=0.5 <=0.5 1     <=0.5 <=0.5
#> [13] <=0.5 1     <=0.5 1     <=0.5 <=0.5 <=0.5 <=0.5 <=0.5 <=0.5 2     1    
#> [25] 2    
random_mic(25, "Streptococcus pneumoniae", "meropenem") # range 0.0625-4
#> Class 'mic'
#>  [1] 0.125 0.125 1     0.25  0.5   0.125 0.125 0.125 0.125 0.125 0.125 0.125
#> [13] 1     0.125 0.5   1     0.125 0.25  0.5   0.25  0.5   0.5   0.5   0.125
#> [25] 0.25 

random_disk(25, "Klebsiella pneumoniae") # range 8-50
#> Class 'disk'
#>  [1] 32 21 23 21 14 22 25 29 29 28 34 34 34 33 13 28 33 34 32 25 18 26 13 21 33
random_disk(25, "Klebsiella pneumoniae", "ampicillin") # range 11-17
#> Class 'disk'
#>  [1] 20 21 15 22 16 22 16 14 21 17 15 19 20 17 18 21 16 20 11 22 19 18 19 11 21
random_disk(25, "Streptococcus pneumoniae", "ampicillin") # range 12-27
#> Class 'disk'
#>  [1] 29 25 31 17 29 21 31 34 33 31 29 30 23 20 33 20 34 32 35 26 26 26 34 30 33
# }