qat (version 0.74)

qat_analyse_histogram_test_2d: Perform a histogram test with a given metric

Description

This check divides the data into blocks, estimates their probability density functions by histograms and compares them by using a given metric.

Usage

qat_analyse_histogram_test_2d(measurement_vector, co_measurement_vector=
measurement_vector, metric="EMD", blocksize=100, numofbars=65, factorofbar=100)

Arguments

measurement_vector

The measurement vector (2d array), which should be tested.

co_measurement_vector

An optional second measurement vector (2d array), which is compared to the frst. The default is the first measurement vector.

metric

Metric of the comparison. Details see below.

blocksize

Number of elements in the first dimension, which should be used for each block.

numofbars

Number of bins of the histogram.

factorofbar

Correction factor for non-value bins.

Value

Details

The field will be divided into blocks in the first dimension, with a length given by the parameter blocksize. From these blocks histograms are computed and afterwards compared. As a metric for the comparison one of the following five options are usable: EMD: Earth Mover's Distance (default); KLD: Kullback-Leibler Distance; JSD: Jenson-Shannon Distance; RMS: Root Mean Square; MS: Mean Square. As a result a field is generated, which includes the results of the comparison between every combination of blocks.

References

Duesterhus, A., Hense, A. (2012) Advanced Information Criterion for Environmental Data Quality Assurance, \_Advances in Science and Research\_, *8*, 99-104.

See Also

qat_analyse_histogram_test_1d

Examples

vec <- array(rnorm(1000), c(100, 20))
vec[51:100, ] <- vec[51:100, ] + 2
result <- qat_analyse_histogram_test_2d(vec, metric="EMD", blocksize=4, numofbars=65)
qat_plot_histogram_test(result$field, "test_emd_2d", result$blocksize, result$numofbars, 
"emd", result$runs)

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