**FUZZEKS** [to Index]

Handling Variograms

### The variogram display in FUZZEKS

In FUZZEKS both curves for experimental and theoretical variogram are
displayed in the box on the left side of the
kriging window:

In the variogram window on the left side the distance is noted on the X-axis:
In order to calculate the experimental variogram value for similar distances
the X-axis is divided into sections.
Each experimental variogram value is displayed as intersection of
the vertical green lines and the
horizontal blue lines. The length of the **vertical green line** indicates
the fuzziness (this is defined in the corresponding options-menu by
default, i.e. the top of the line indicates the largest possible
value and the bottom indicates the lowest possible value).

The **horizontal blue line** indicates how many data points have been taken
into account when calculating the experimental variogram value.
The **red curve** is the theoretical variogram (a function of the distance).
It is determined by the input fields above and below the variogram window
(user-supplied inputs, see
Theoretical variogram fitting).

Both experimental and theoretical variogram use the same
coordinate-system.

Note: If the range or sill value (of the theoretical variogram) are too small,
the curves lie outside the
display-area and no experimental variogram can be seen. If a new data set
is used, one should use relatively large values for both fields first.
The **range** can be overestimated by about the *largest distance*
between two data points. The **sill** can be overestimated by about the
*half of the square of the largest difference between the values* of two
data points.

The next pages deal with