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Calculate the mean, sd and maximum difference value of measurements/observations

Source: R/01_summary_measure.R
calculate_summary.Rd

Get the mean, sd and maximum difference value of the measurements/observations made by a single observer across multiple subjects

Usage

calculate_mean(measures, index = NULL)

calculate_sd(measures, index = NULL)

calculate_max(measures, index = NULL)

Arguments

measures

A vector of measurements/observations made by a single observer across multiple subjects

index

A character vector with length equal to `measures` specifying the factors to be used to group the measurements/values into before applying the summary function. For a single observer, this will tend to be the type of measurement made if `measures` is a vector of measurements/observations of different types e.g., weight and height. This is *optional* and is set to NULL by default. This would indicate that the summary metrics will be made for the values in `measures` without any grouping.

Value

A numeric value for the summary measure of measurements/observations if `index` is NULL. A named numeric vector for the summary measure of measurements/observations grouped by the factor specified by `index`

Examples

## Get the mean of weight measurements by observer 0 (supervisor) from the
## smartStd dataset
x <- smartStd[smartStd$observer == 0, ]
calculate_mean(c(x$weight1, x$weight2))
#> [1] 14.655

## Get the mean weight, height and muac measurements by observer 0 from the
## smartStdLong dataset
x <- smartStdLong[smartStdLong$observer == 0, ]
calculate_mean(x$measure_value, x$measure_type)
#>     Var1    Freq
#> 1 height  95.495
#> 2   muac 164.350
#> 3 weight  14.655

## Get the sd of weight measurements by observer 0 (supervisor) from the
## smartStd dataset
x <- smartStd[smartStd$observer == 0, ]
calculate_sd(c(x$weight1, x$weight2))
#> [1] 1.793988

## Get the sd of weight, height and muac measurements by observer 0 from the
## smartStdLong dataset
x <- smartStdLong[smartStdLong$observer == 0, ]
calculate_sd(x$measure_value, x$measure_type)
#>   height     muac   weight 
#> 4.953306 9.626034 1.793988 

## Get the max difference of weight measurements by observer 0 (supervisor)
## from the smartStd dataset
x <- smartStd[smartStd$observer == 0, ]
calculate_max(abs(x$weight1 - x$weight2))
#> [1] 0.07378648

## Get the max difference of weight, height and muac measurements by observer
## 0 from the smartStd dataset
x <- smartStd[smartStd$observer == 0, ]
calculate_max(c(abs(x$weight1 - x$weight2),
                abs(x$height1 - x$height2),
                abs(x$muac1 - x$muac2)),
              c(rep("weight", 10), rep("height", 10), rep("muac", 10)))
#> height   muac weight 
#>    2.2   11.0    0.2