Process Help PANELK - estimate the average value and the estimation variance of irregular shaped 2-D panels using kriging.

 

Process Name	Menu Path	Link to Command Table
PANELK	Access using command line only	Click here

 

• Introduction
• Files, Fields and Parameters
• Notes
• Example
• Errors

Introduction

This process estimates the average value and the estimation variance of irregular shaped 2-D panels using kriging.

Panels are defined as a series of 2-D points in a standard DATAMINE string file. The value of ZP is ignored. Several panels may be held in the same file, all of which will be evaluated in a single run of the process. It does not matter whether the panel strings are open or closed. VMETHOD controls the method by which the variogram model is defined:

 

VMETHOD=1
A single structure spherical model is used, defined by parameters NUGGET etc. This method is consistent with earlier versions of the process, and is the default.

VMETHOD=2
The standard range of variogram models is available, defined by interactive prompting. This is consistent with processes KRG3DB, PTK3DA etc. VMETHOD=1 then the two variogram ranges are defined by RANGE1 and RANGE2 , and the anisotropy angle by VGANGLE1. The angle is measured clockwise from the North to direction 1. Direction 2 is perpendicular to direction 1 in the same plane as the panels. It does not matter whether direction 1 represents the major or minor axis.

The following definitions are equivalent:

RANGE1 100 300 100 RANGE2 300 100 300 VGANGLE1 50 140 230

If VMETHOD=2 then the user is prompted interactively to enter the variogram parameters for all 3 directions. The data for the 3rd direction, perpendicular to the plane of the panels, is not used, but values must still be entered for that direction. It is suggested that values in the third direction are set equal to the values in direction 1 or direction 2. Whatever values are entered for the third direction,the range must not be set to zero. - only samples within a distance SEARCH of the centre of gravity (CG) ofthe panel are selected. - if more than NMAX lie within the search area, then the nearest NMAX to the CG are selected. NSIM.

The origin of the grid is at a point defined by the minimum X and Y of the panel points. MINSIM then the value of NSIM is increased by 1, and the process is repeated until the number of internal points exceeds MINSIM. The maximum number of simulated points allowed is 1000. Processing speed is approximately proportional to the square of the number of samples in the kriging matrix. It is also influenced to a lesser extent by the number of simulated points in the panel.

If two or more samples have the same X and Y coordinate then an error will be reported as ERR 131 in SOLVED and ERR 122 in PKM3DA.

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Files, Fields and Parameters

Input Files

Name	Description	I/O Status	Required	Type
IN1	Input sample data file. This must contain the three fields X , Y and VALUE.	Input	Yes	Undefined
IN2	The input panel data file. This must contain the 4 fields PANEL , PTN , XP field must be defined explicitly, and will often be called PVALUE. The strings may be open or closed.	Input	Yes	Undefined

Output Files

Name	I/O Status	Required	Type	Description
OUT	Output	No	Undefined	The output results file. This will contain the following fields: -FIELD The grade being kriged. -PANEL Panel identifier copied from the IN2 file. -KRIGEST The kriged estimate. -KRIGVAR The kriging variance. -NUMSAM The number of samples used to make the kriged estimate. -AREA The area inside the panel. -SIMPTS The number of simulated points inside the panel. -FVALUE The average value of the variogram in the panel.

Fields

Name	Description	Source	Required	Type	Default
X	X coordinate of sample data in the IN file.	IN	Yes	Numeric	X
Y	Y coordinate of sample data in the IN file.	IN	Yes	Numeric	Y
VALUE	Field to be kriged in the IN file.	IN	Yes	Numeric	Undefined
PANEL	Panel identifier. This is a numeric field in the IN2 file. Its name will often be PVALUE.	IN2	Yes	Numeric	PVALUE

Parameters

Name	Description	Required	Default	Range	Values
NUGGET	Nugget variance (0).	No	0	Undefined	Undefined
VAR1	Spatial variance (1). The difference between the nugget variance	No	1	Undefined	Undefined
RANGE1	The range of the variogram in direction 1. (1) Direction 1 is used for defining the anisotropy angle, [ VGANGLE1] , which is measured clockwise from the North. It does not matter whether direction 1 is the major or minor axis.	No	1	Undefined	Undefined
RANGE2	The range of the variogram in direction 2, perpendicular to direction 1. (1)	No	1	Undefined	Undefined
VGANGLE1	The angle between the N axis and direction 1, measured clockwise from N in degrees (0).	No	0	Undefined	Undefined
SEARCH	Maximum search distance from centre of gravity of panel (9999).	No	9999	Undefined	Undefined
NMAX	The maximum number of samples to be used. The default is (50), but the maximum is 300 for a PC and 1900 for a workstation.	No	50	1,1900	Undefined
NSIM	The starting value for the number of simulated points in the X and Y directions for panel simulation. The default value of (20) means that the initial square grid has 20x20=400 points. Refer to the summary description of PANELK in the helpfile or process summary for details of the panel simulation method.	No	20	Undefined	Undefined
MINSIM	Minimum number of simulated points in panel. The default is (400).	No	400	Undefined	Undefined
VMETHOD	Method for defining variogram parameters (1) Option Description 1 Use parameters NUGGET , VAR1 , RANGE1 , RANGE2 , and VGANGLE1. This is consistent with earlier versions of PANELK and can be used for a single structure spherical model. 2 Define parameters using interactive prompts. This method allows a selection of variogram models, defined using VGRAM.	No	1	1,2	1,2
VGRAM	Variogram model type (1). Possible values are: Option Description 1 Single structure spherical model. 2 Two structure spherical model. 3 Linear model. 4 De Wijsian model. 5 Exponential model. 6 Gaussian model. 7 Experimental model. 8 NOT USED. 9 NOT USED. 10 Multi structure spherical model with anisotropy.	No	1	1,10	1,2,3,4,5,6,7,10
PRINT	Output control flag (1). Option Description 0 Minimum output. Just a summary of the sample data and a table of results is output. 1 As 0 plus a summary of all input files, fields and parameters. 2 As 1 plus a listing of all simulated points, plus all samples and kriged weights. 3 As 2 plus a listing of panel points.	No	1	0.3	0,1,2,3