Import ESTIMA Parameters

Your application provides a range of options for estimating grades within a block model.

There are several processes available to perform the heavy lifting, and several more supporting them. Which process is used depends on the type of estimation you are performing:

You can use the parameters files of the ESTIMA process within COKRIG. COKRIG is used during advanced estimation.

This topic describes key differences between the parameter files that are expected by the ESTIMA and COKRIG processes, and the transformation that will be applied if ESTIMA parameters are imported into the Advanced Estimation function.

As the parameter file format between these processes is slightly different, it is necessary for the Advanced Estimation tool to map settings between imported COKRIG parameters and those expected by the COKRIG process. Some parameters supported by ESTIMA are either not supported in COKRIG, or may be only partly supported. Some are identical in both processes, which means no transformation is required.

Note: You can import any combination of estimation parameter files using the Parameters panel. For example, if required, you can just import a variogram model file.

If you are attempting to recreate a prior ESTIMA/ESTIMATE estimation in COKRIG, you need to be aware of the differences in parameter files as, during import to Advanced Estimation, some assumptions have to be made regarding the type of estimation you are performing.

For example, macro kriging is available in ESTIMA but is not available in COKRIG, and some parameters associated with kriging (KRIGNEGW, KRIGVARS) aren't available in COKRIG either. Conversely, in COKRIG, search volume anisotropy is always specified, but can be disabled in ESTIMA. In addition, If Dynamic Anisotropy is used in COKRIG, it needs to be for the same angle field names for all variograms or search.

Because of the differences between supported parameters and parameter file specification between the two processes, the Advanced Estimation tool will review parameters files generated by ESTIMA during import and either automatically map between the two processes, or provide feedback to indicate where parameter file information is incompatible and has been ignored.

Importing ESTIMA Parameter Files

The Parameters panel, part of the Advanced Estimation tool, is used to import or export parameters to and from the multivariate estimation routines.

In Import mode (selectable at the top of the panel), you can either import COKRIG-format parameter files (estimation, field, variogram, search and custom zones) or ESTIMA-format files (estimation, variogram, search).

Field and custom zones parameter files are not used in ESTIMA, so these options are unavailable if you choose to Use ESTIMA format file(s). ESTIMA does not support co-estimation or soft boundaries. As such, the estimation, variogram and search parameter files from ESTIMA represent the full 'set'.

In summary, the process by which you can import ESTIMA parameter files into Advanced Estimation is:

  1. Set up your scenario in the Advanced Estimation tool. See Advanced Estimation & Variography

  2. Select your samples and attributes. See Select Samples.

  3. Select your prototype model. See Select Prototype

  4. On the Parameters panel, select Import.

  5. Select Use ESTIMA format file(s).

  6. Select the Estimation Parameters, Variogram model andSearch parameters files (or any combination of these files, or a single file.

  7. Click Import and review the messages in the Output control bar. This information describes the transformations that may have been applied as part of the import process.

  8. Continue setting up your model prototype using the Advanced Estimation tool.

Following import, the appropriate panels in the Advanced Estimation tool are populated according to the values found in the external files.

Note: Previously imported parameter files in the Advanced Estimation routine are not overwritten or deleted by subsequent import operations. For example, importing 2 sets of variogram parameters won't cause previously imported data to be lost.

For a more detailed description of the way imported parameters are transformed to a COKRIG-friendly format, see "Parameter File Mapping Logic", below.

Parameter Mapping Logic

Generally, the following rules apply when importing ESTIMA parameter files into the Advanced Estimation tool running COKRIG:

ESTIMA Command Line Parameters

In ESTIMA, some of the parameters are passed into the command line, for example, the number of discretization points and parent cell estimate. So, when importing these from ESTIMA, assumptions are made that the number of points is 3 x 3 x 3 (DISCX, DISCY, DISCZ) and parent cell estimation (PARENT=1) is always used. These parameters can be changed in the Define Estimation screenafter import. 

IMETHODS

Not all estimation methods used in ESTIMA are supported by COKRIG. i.e. The estimation methods IMETHOD=5 = Sichel's t estimator, 6 = Ordinary macro kriging, 7 = Simple macro kriging or 9 = Correlation factor method are not supported. 

If the IMETHODs 101 or 102 are used, then equivalent parameters are added to the COKRIG fields file. 

All other estimation methods are supported. 

Parameters not supported in COKRIG

Cokrig has no equivalent for:

  • resetting Kriging negative weights to 0 (KRIGNEGW)

  • resetting the sill to the variance (KRIGVARS)

Differences in Dynamic Anisotropy

Dynamic Anisotropy is handled different in COKRIG to ESTIMA. In COKRIG, the fields are passed into the command line, so the anisotropy fields need to be the same for all estimates. In ESTIMA, these fields were in the variogram and/or search parameter file, so these could be different for each estimate. If you were using different anisotropy fields for each run in ESTIMA, you might need to run consecutive COKRIG estimates to achieve the same result. 

OCTANTS versus SECTORS; and MAXKEY

If OCTANTS were used in ESTIMA, you should check the parameter setup in COKRIG very carefully as there is not a 1:1 mapping. If the system is unable to determine a corresponding setup for COKRIG, the parameters will be ignored which will result in differences in your estimate. 

As ESTIMA's OCTANTS breaks the space into 8 parts, the following COKRIG parameters best describe 8 parts : NSECTOR=4 and SPLITSEC=1

MINOCT can be approximately converted to MAXEMPSC i.e. MAXEMPSC= 8 – MINOCT (total number of octants – number of octants that require values). See Define Search Volumes.

We can only convert to OCTANTS if MINPEROC=1 and MAXPEROCT=4. Any other combination cannot be directly converted. 

MAXKEY in ESTIMA refers to the total space, where as in COKRIG it refers to MAXKEY per Sector.  If no SECTORS are used it is converted directly. If it is used in conjunction with OCTANTS, then it is multiplied by 8. 

Variogram Structures

ESTIMA and COKRIG have equivalent structures for 1 (Spherical), 3 (Exponential) or 4 (Gaussian). Structures 2 (Power) or 5 (De Wijsian) are not supported in COKRIG, so these are not imported. 

The following tables describe, for each of the three ESTIMA parameter files that can be imported, what will happen to the values of each attribute when imported into the Advanced Estimation Module.

A tick in the ESTIMA column indicates the presence of the attribute in parameter files used by ESTIMA. A red cross indicates the attribute exists in COKRIG, but not ESTIMA. Similarly, the COKRIG column indicates if an attribute exists (and is required by) in COKRIG parameter files.

The following acronyms are used throughout this table:

  • EPAR: Estimation parameter file

  • VPAR: Variogram parameter file

  • FPAR; Fields parameter file

  • NN: Nearest Neighbour

  • ID: Inverse Power of Distance

  • OK: Ordinary Kriging

  • AE: Advanced Estimation

Estimation Parameters

Field Name

Type

ESTIMA

COKRIG

Description

EDESC

A

 YES NO

If detected, an equivalent attribute is created in the COKRIG estimation parameter file.

This field is not used, but it can be in the parameter file for your convenience.  

EREFNUM

N

 YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

A check is made to ensure this number is unique within this file.

VSETNUM

 N NO YES

During import, the value stored in the imported VREFNUM column is used to populate the VSETNUM column.

A warning is issued if this record does not have a matching reference in the VPAR file:

“VSETNUM does not have a matching value in variogram model file”

VREFNUM

 N YES NO

This field will not be imported, but its values will be used to populate VREFNUM

SREFNUM

 N YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

A warning is issued if this field does not have a matching reference in SPAR file:

“SREFNUM does not have a matching value in search parameter file”

IMETHOD

 N YES YES

Import directly for estimation method: 1=NN, 2=ID, 3=OK

For 4=SK

  • If LOCLMNP=1 then set to 11 (i.e. SK with local mean) and set LOC_MEAN in FPAR to the value of LOCALM_F
  • if LOCLMNP=2 then set to 4 (i.e. SK). LOC_MEAN is not set in FPAR.
  • Values of 101 and 102 – Ensure that FPAR is populated with COVZZSTR, SLPZZSTR and KRIGEFF (For 101) and LAGRANGE (for 102) for any values with the same input grade field (VALUE_IN) and IMETHOD=3. Do not import the record, but adjust any other records with this VALUE_IN.

For IMETHOD=5,6,7 and 9 a warning is issued:

“Selected Estimation (IMETHOD=X; Method name) method not supported in Cokrig.”. Records with these values are ignored.

For reference, in ESTIMA:

5 = Sichel's t estimator.

6 = Ordinary macro kriging.

7 = Simple macro kriging.

9 = Correlation factor method.

POWER

 N YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

If IMETHOD!=2, a warning is issued:

“Power will not be used as ID not selected as estimation method”

ADDCON

 N YES NO

Functionality does not exist in COKRIG. Warning issued and data is ignored.

KRIGNEGW

 N YES NO

If missing or value = 0 (default), data is ignored.

If value = 1, a warning is issued:

“An equivalent to KRIGNEGW does not exist in COKRIG. Parameter ignored.”

KRIGVARS

 N YES NO

If value is missing or =1 (default), data is ignored.

If value = 0, a warning is issued:

“An equivalent to KRIGVARS does not exist in COKRIG. Parameter ignored.”

ANISO

 N YES NO

IF 0, a warning is issued:

 “Search volume anisotropy always in Cokrig, ANISO 0 not supported; parameter ignored.”.

If 1, and fields do not exist, then the search ellipsoid used. No warning is issued. SDYNAISO=0 and VDYNAISO=0

If 1 and angle fields exist, then DA fields are set on the Select Prototype screen.

If fields (SANGL1_F, SANGL2_F and SANGL3_F) exist in SPAR file, then SDYNAISO=1.

If fields (VANGL1_F, VANGL2_F and VANGL3_F) exist in EPAR and VDYNAISO=1. If 2, a warning is issued:

“Search volume anisotropy always in COKRIG, so ANISO 2 not supported; parameter set to 1.” Set to 1.

If Dynamic Anisotropy is used in COKRIG, it must be for the same angle field names for all variograms or search.

ANANGLEi

 N YES NO

i=1,2,3

Functionality does not exist in COKRIG.

If ANISO=2 then a warning is issued:

“ANANGLE1, does not exist in COKRIG, parameter ignored”

ANDISTi

 N YES NO

i=1,2,3

Functionality does not exist in COKRIG.

If ANISO=2 then a warning is issued:

"ANDIST, does not exist in COKRIG, parameter ignored”

SDYNAISO

 N YES YES

See ANISO.

This is set to 1 if the fields (SANGL1_F, SANGL2_F and SANGL3_F ) exist in SPAR, otherwise this is set to 0.

VDYNAISO

 N YES YES

Set to 1 based on presence of fields (VANGL1_F, VANGL2_F and VANGL3_F) in EPAR, otherwise set to 0.

DISCX

 N YES YES

Set to 3 in COKRIG

A warning is issued:

“Unable to import discretization settings for Estima. Discretization in X set to 3”

DISXY

 N YES YES

Set to 3 in COKRIG

A warning is issued

“Unable to import discretization settings for Estima. Discretization in Y set to 3”

DISCZ

 N YES YES

Set to 3 in COKRIG

A warning is issued:

“Unable to import discretization settings for Estima. Discretization in Z set to 3”

USEPK

 N

NO

 YES

Set to 0

A warning is issued:

if (IMETHOD=3,4 or 11) “Unable to set USEPK. Only set if discretization is 1x1x1”

PARENT

 N YES YES

Set to 1

A warning is issued:

“Unable to import parent cell estimation settings for Estima. Parent cell estimation set to 1”

VALUE_IN

 A YES YES

Check grade exists in AE and sample file, and if it doesn’t then it is added

Set value to IN_VAR in Fields.

VALUE_OU

 A YES YES

Set value to EST in Fields.

NUMSAM_F

 A YES YES

Set value to NUMSAMP in Fields.

SVOL_F

 A YES YES

Set value to SINDEX in Fields.

VAR_F

 A YES YES

Set value to VAR in Fields.

MINDIS_F

 A YES YES

If set, A warning is issued:

“MINDIS_F is not supported by Cokrig; parameter ignored”

LOCALMNP

 N YES

NO

See IMETHOD.

LOCALM_F

 A YES YES

See IMETHOD.

Set value to LOCALM_F in Fields.

VANGLi_F

 A YES

NO

See ANISO.

Fields Parameter File

Field Name

Type

ESTIMA

COKRIG

Description

EREFNUM

 N YES YES

From EPAR

IN_VAR

 A YES YES

From EPAR - VALUE_IN

LOC_MEAN

 A YES YES

From EPAR - LOCALM_F

EST

 A YES YES

From EPAR - VALUE_OUT

VAR

 A YES YES

From EPAR - VAR_F

NUMSAMP

 A YES YES

From EPAR - NUMSAM_F

WTOFMEAN

 A

NO

 YES

Not imported

SUMPOSWT

 A

NO

 YES

Not imported

CORZZSTR

 A

NO

 YES

Not imported

COVZZSTR

 A

NO

 YES

From EPAR, Updated records with same grade field that also have IMETHOD=101

COVZ1SZS

 A

NO

 YES

Not imported

SLPZZSTR

 A

NO

 YES

From EPAR, Updated records with same grade field that also have IMETHOD=101

VARZSTR

 A

NO

 YES

Not imported

KRIGEFF

 A

NO

 YES

From EPAR, Updated records with same grade field that also have IMETHOD=101

LAGRANGE

 A

NO

 YES

From EPAR, Updated records with same grade field that also have IMETHOD=102

SINDEX

 A YES YES

From EPAR - SVOL_F

Search Parameter File

Field Name

Type

ESTIMA

COKRIG

Description

SDESC

 A YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

 

SREFNUM

 N YES YES

A check is made to ensure this value exists in EPAR, otherwise a warning is issued.

SMETHOD

 N YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files. (values 1 or 2)

SDIST1/2/3

 N YES YES

The contents of these attributes are matched exactly between ESTIMA and COKRIG parameter files.

SANGLE1/2/3

 N YES YES

The contents of these attributes are matched exactly between ESTIMA and COKRIG parameter files.

SAXIS1/2/3

 N YES YES

The contents of these attributes are matched exactly between ESTIMA and COKRIG parameter files.

 (Values 1, 2 or 3)

OCTMETH

N YES YES

If set to 0, set NSECTORS to 0;

If set to 1, set NSECTORS=4 and SPLITSEC=1. This creates an equivalent of 8 “octants”.

A warning is issued:

“Octants (Used by ESTIMA) do not directly translate to sectors (Used by COKRIG). Using 4 sectors, split horizontally).  

MINOCT

N YES YES

If OCTMETH=1

Use this value to set MAXEMPSC.

MAXEMPSC= 8 – MINOCT (i.e. total number of octants – number of octants that require values)

A warning is issued

“Minimum Octants does not directly convert to number of empty sectors in COKRIG. Setting MAXEMPSC to X.”

MINPEROC

N YES YES

OCTMETH=0 Ignore,

If OCTMETH=1 and MINPEROC=1 and MAXPEROC=4

A warning is issued:

“Equivalent minimum and maximum samples per octant have been determined”.

Otherwise, if OCTMETH=1 and (MINPEROC is not 1 and MAXPEROC is not 4)

A warning is issued:

“No equivalent minimum and maximum samples per octant have been determined for Cokrig. MINPEROCT and MAXPEROC Parameter ignored. This will result in differences in your estimate between Estima and Cokrig.”

MAXPEROC

N YES YES

See MINPEROCT

MINNUM1

N YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

MAXNUM1

N YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

SVOLFAC2

N YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

MINNUM2

N YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

MAXNUM2

N YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

SVOLFAC3

N YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

MINNUM3

N YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

MAXNUM3

N YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

SVOLFACi

N

NO

 YES

Not required

MINNUMi

N

NO

 YES

Not required

MAXNUMi

N

NO

 YES

Not required

MAXKEY

N YES YES

If absent, set to 0

IF OCTMETH=0, this us copied directly.

IF OCTMETH=1 then MAXKEY is calculated as Estima value*8

OPTKEY

N

NO

 YES

If absent, set to 0

No equivalent exists in ESTIMA.

NSECTORS

N YES YES

See OCTMETH.

Set to 0; If OCTMETH=1, set to 4

SPLITSEC

N YES YES

See OCTMETH.

Set to 0; If OCTMETH=1, set to 1

MAXEMPSC

N YES YES

See MINOCT

MAXEMPSC= 8 – MINOCT

MVSEARCH

N

NO

 YES

Set to 0 (multi-variate estimation not supported by ESTIMA)

KALLIBLK

N

NO

 YES

Set to 0

CAPPING

N

NO

 YES

Set to 0

CAPDIST

N

NO

 YES

Set to absent

CAPGRADE

N

NO

 YES

Set to absent

SANGL1_F

A YES YES

Only a single combination of SANGL1_F, SANGL2_F and SANGL3_F is suppported.
If a second combination occurs, a warning is issued:

“Multiple combinations of SANGL1_F, SANGL2_F and SANGL3_F cannot be run in COKRIG. Parameter ignored”.

SANGL2_F

A YES YES

See SANGL1_F

SANGL3_F

A YES YES

See SANGL1_F

Variogram Model Parameter File

Field Name

Type

ESTIMA

COKRIG

Description

VDESC

 A YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

GRADE

 A NO YES

From EPAR - VALUE_IN

GRADE2

 A NO YES

From EPAR - VALUE_IN (Same as GRADE)

VSETNUM

 N NO YES

Copy from VREFNUM (Check this exists in EPAR)

VREFNUM

 N YES YES

Same as VREFNUM

GOODFITP

 N NO YES

Not required

FITCONV

 N NO YES

Not required

VANGLE1/2/3

 N YES YES

The contents of these attributes are matched exactly between ESTIMA and COKRIG parameter files.

VAXIS1/2/3

 N YES YES

The contents of these attributes are matched exactly between ESTIMA and COKRIG parameter files.

NUGGET

 N YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files.

STi

 N YES YES

The contents of this attribute are matched exactly between ESTIMA and COKRIG parameter files if value is 1, 3 or 4.

If 2 or 5 a warning is issued:

“Structure type {2=Power / 5-De Wijsian} not supported in Corkig. Variogram model will not be imported”. Skip record.

STiPAR1/2/3/4

 N YES YES

The contents of these attributes are matched exactly between ESTIMA and COKRIG parameter files.

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