CStats:MinMaxClipMean

The MinMaxClipMean method computes the mean value of a data sample, excluding the minimum and maximum pixel value from the sample. Use this method to avoid a biased result when the region is suspected to contain one deviant high value and one deviant low value. The sample may be a Lua table or a class object of type CImage, CArray, or CMatrix. For CImage and CMatrix objects, an optional CRect object can be used to define the points used in the calculation.

Syntax

nMean, nStdDev = CStats:MinMaxClipMean( table )

nMean, nStdDev = CStats:MinMaxClipMean( CImage, )

nMean, nStdDev = CStats:MinMaxClipMean( CImage, CRect )

nMean, nStdDev = CStats:MinMaxClipMean( CArray )

nMean, nStdDev = CStats:MinMaxClipMean( CArray, CRect )

nMean, nStdDev = CStats:MinMaxClipMean( CMatrix )

where

table is a lua table containing the data.

CImage, CArray, and CMatrix are class objects containing the data to measure,

CRect is a CRect rectangle object that defines the region to measure.

nMean and nStdDev are the min/max clipped mean and the standard deviation of the data. On failure, 0,0 is returned.

Example

Suppose a CImageI and a CRectR exist. The following script returns the mean value inside a rectangle on the image, discarding both the single highest and single lowest pixel values:

nMean = S:MinMaxClipMean()	-- returns the mean value
Printf("mean=%lg\n", nMean )	-- list the results
S:delete()	-- when done with S, remove it from memory

The following script returns the min/max-clipped mean value for a table of data:

S = CStats:new()	-- create a CStats object
t = { 4, 4, 2, 5, 6.4, -1.42, -12, 3.4 }	-- create some data in a table
Printf("mean=%lg\n", S:MinMaxClipMean(t) )	-- list the result