gx.stats: Function to Compute and Display Summary Statistics

Description

Function to compute summary statistics for a 'one-page' report and display in inset. Function may be used stand-alone, and is used as an engine for the gx.summary.* series of functions

Usage

gx.stats(xx, xlab = deparse(substitute(xx)), display = TRUE)

Arguments

name of the variable to be processed.

xlab

a title for the table. It is often desirable to replace the default table title of the input variable name text string with a more informative title, e.g., xlab = "Cu (mg/kg) in <2 mm="" o-horizon="" soil"<="" code="">.

display

if display = TRUE the summary statistics are displayed on the current device. If display = FALSE output is suppressed.

Value

statsthe computed summary statistics to be used in function inset, and by gx.summary.* functions. The list returned, stats, is a 32-element vector, see below:
[1:10]the minimum value, and the 1st, 2nd, 5th, 10th, 20th, 25th (Q1), 30th, 40th and 50th (Q2) percentiles.
[11:19]the 60th, 70th, 75th (Q3), 80th 90th, 95th, 98th and 99th percentiles and the maximum value.
[20]the sample size, N.
[21]the Median Absolute Deviation (MAD).
[22]the Inter-Quartile Standard Deviation (IQSD).
[23]the data (sample) Mean.
[24]the data (sample) Variance.
[25]the data (sample) Standard Deviation (SD).
[26]the Coefficient of Variation as a percentage (CV%).
[27]the Lower 95% Confidence Limit on the Median.
[28]the Upper 95% Confidence Limit on the Median.
[29]the log10 transformed data (sample) Mean.
[30]the log10 transformed data (sample) Variance.
[31]the log10 transformed data (sample) SD.
[32]the log10 transformed data (sample) CV%.
If the minimum data value is <= 0<="" code="">, then stats[29:32] <- NA.

Details

The summary statistics comprise the data minimum, maximum and percentile values, robust estimates of standard deviation, the Median Absolute Deviation (MAD) and the Inter Quartile Standard Deviation (IQSD), and the mean, variance, standard deviation (SD), coefficient of variation (CV%), and the 95% confidence bounds on the median. When the minimum data value is > 0 summary statistics are computed after a log10 data transformation and exported back to the calling function.

Examples

Run this code

## Make test data available
data(kola.o)
attach(kola.o)

## Generates an initial display
gx.stats(Cu)

## Provides a more appropriate labelled display
gx.stats(Cu, xlab = "Cu (mg/kg) in <2 mm O-horizon soil")

## Detach test data
detach(kola.o)