Variogram calculation

In MatterCliff Version 1.0, the only possible Variogram type is a 'Number of discontinuities by distance' variogram.

To calculate and display a variogram follow this scheme:

  1. click on the Variogram button of a Spacing datasheet (see Figure 2)
  2. enter the range of scanline distance for calculating the number of discontinuities. The default range is 1
  3. enter the maximum number of lags to display. The default value is 20. If this number is greater than the possible number for the total length of the scanline, the unnecessary lags are ignored

 

Figure 3 : Variogram calculated for 500 data from a random exponential distribution (total distance of 2573.32, range = 10, 20 lags)

 

During the calculation, MatterCliff first calculate the number of discontinuities in the given range. Then, the lags used for the variogram calculation are 1 range, 2 ranges, 3 ranges, … In general, a number of lags corresponding to half of the total length of the scanline is sufficient.

The resulting variogram is displayed on a with (see Figure 3 above):

To change the text of a label, double-click on it.

 

Figure 4 : Variogram calculated for 55 data from the clustered distribution shown below (total distance of 33.35, range = 1, 20 lags). The variogram curve reflects the periodic characteristic in the spatial distribution

 

Variogram interpretation

For the interpretation of the variograms some trends may be used:

 

Figure 5 : Variogram calculated for 17 data from the incrising distance distribution shown
below (total distance of 3.01, range = 0.2, 14 lags). The incrising variogram curve reflects
a continuous incrise or decrise of the distance between successive discontinuities