210123348 Interpolation Features and Options

8/12/2019 210123348 Interpolation Features and Options

1/22

Page 1

Interpolation Features and Options


Introduction

The purpose of this workshop is to review and clarify some of the important interpolation features and optionsavailable in MineSight, including updates made since the last couple of years.

Interpolation Features and New Developments

1. Ellipsoidal Search Viewing in MineSight3-D and Debug Options.

Procedure p624db.dat is used to output in MineSight3-D format an object representing the ellipsoidal search. The

ellipse created is based on the lengths of the major, minor, and vertical axes used in the interpolations, as well as the

orientation used (see figure 1).

Figure 1. Ellipse in MineSight3-D


2/22


Page 2

Figure 2. Detailed Kriging Debug Report

This same procedure outputs a detailed report with detailed composite information (as used in interpolation). See figure

2.

** DEBUG FOR ROW= 75 YMID= 5490.0 Max Dist (PAR4)= 240.0

Kriging matrix:

0580.0 2110.0 7060.0 7060.0 8110.0 3010.0 3740.0 0000.1

2110.0 0580.0 4010.0 8110.0 5850.0 4850.0 0210.0 0000.1

7060.0 4010.0 0580.0 3740.0 5010.0 8900.0 8630.0 0000.1

7060.0 8110.0 3740.0 0580.0 8210.0 4010.0 7060.0 0000.1

8110.0 5850.0 5010.0 8210.0 0580.0 8340.0 5310.0 0000.1

3010.0 4850.0 8900.0 4010.0 8340.0 0580.0 3010.0 0000.1

3740.0 021.0 8630.0 7060.0 5310.0 3010.0 0580.0 0000.1

0000.1 0000.1 0000.1 0000.1 0000.1 0000.1 0000.1 0000.1

3820.0

1420.0

5720.0

5720.0

8320.0

8220.0

2520.0

0000.1

Covariance between samples Covariance between block and samples

Kriging Variance = 0.05082 # PTS = 7

Lagrange Multiplier = -0.01091

NO. OF COMPOSITES IN OCTANTS/QUADRANTS= 10 10 6 0

loC XDNI TSID)jdA( TSAE HTRON .VELE 1EULAV HD THGIEWGIRK dQ/tcO

57 94 95.96 05.0242 04.6845 0.5342 0010.0 25 00+E24801.0 3

57 73 41.17 02.3252 07.4345 0.5642 0080.0 401 00+E71401.0 2

57 05 91.17 05.0242 04.6845 0.0242 0030.0 25 00+E96402.0 3

57 84 91.17 05.0242 04.6845 0.0542 0030.0 25 10-E19359.0 3

57 54 28.17 06.7152 03.1445 0.0842 0070.0 401 00+E60171.0 2

57 92 16.47 07.8252 00.8245 0.0542 0070.0 401 00+E58071.0 2

57 74 87.57 05.0242 04.6845 0.5642 0010.0 25 00+E24541.0 3

Block (75, 75) Calculated = 0.0438 0.0508 69.5932 7.0000 2.0000

Kriggin estimate, kriging variance, distance to the closest composite, # if composites, # of drill holes

Local Error (Variance) = 0.000102

Row: 75 5490.0 Comps: 1 64 #Calc 1

End of BENCH 35 2435.0 #Blocks Calculated 1 100.0% Completed


3/22

Page 3


2. Ellipsoidal Search Versus Variogram Ranges

There are two places where you will be asked to define length of a major, minor and vertical axes. One is for the

ellipsoidal search and applies only to the selection of the composites (see figure 3).

Figure 3. Optional Search Panel


4/22


Page 4

The second one is for the variogram ranges and it applies only to the calculation of the kriging weights (see figure 4).

Figure 4. Variogram Parameters Panel

Those ranges are likely the same. If not, try to use the same major versus minor versus vertical length relationship.

3. Ellipsoidal Search Versus Primary Search Parameters

The primary search parameters define a 3-D volume around a block (see figure 5 on next page). They are used to

initially screen out the composites to be used for a given block. Four major search parameters have to be defined:

X-search parameter (par1)

Y-search parameter (par2)

Z-search parameter (par3)

Max 3-D search parameter (par4)


5/22

Page 5


The search for the composites around the block includes the volume from the center of the block the distances in x,

y, and z directions. If the max 3-D search distance (par4) is less than or equal to the smallest of par1-3, then the search

volume has been reduced to a sphere (see figure 5).

Figure 5. Major search parameters

If par3 is smaller than the bench height, the search volume is reduced to a 2-D plane rectangular or circular search.

The ellipsoidal search follows the primary search, however this is optional. If you want to have a true ellipsoid, then

the search box around the block should be big enough to include the ellipsoid; otherwise the smaller box will truncate the

ellipsoid. The safest way to apply this is to ensure par4 is equal to the length of the major axes of the ellipsoid. See

figure 6.

Figure 6. Ellipse inside a sphere


6/22


Page 6

4. Effect of Weighting Factor

The most common use of a special weight during estimation is to adjust the weights to take into account aberrant

composite lengths or densities. If a composite is only defined for part of its length, then it should only contribute to the

interpolation according to its length.

In M624V1 the composite length weighting is done after the Kriging weights are computed as follows:

Grade = [sum (grd x Kwt x wt)] / [sum (Kwt x wt)]

grd = grade

wt = weighting item

Kwt = Kriging weights

In the debug report, the program prints the kriging weights before using the weighting factor. Therefore you see the

original weights.

If you use weighting factors in IDW, the grades will be calculated as follows:

grd1 x (wt1 /d1)2

+ grd2 x (wt2 /d2)2

(wt1/d1)2+ (wt2/d2)2

where

grd = grade

d = distance

wt = weighting item

A new option was added to apply a weighting factor from a weight item after using the inverse distance:

grd1 x wt1 /(d1)2+ grd2 x wt2 /(d2)2 wt1/(d1)2+ wt2/(d2)2


7/22

Page 7


5. Search from Mid-Point of the Bench

If the check for fixed length/ZMID composites switch is ON, this indicates the bench midpoint elevation will be used.

This option will work if the composites are indeed stored at the bench midpoint elevation option (see figure 7).

Figure 7. Composite Stored at Mid-bench.

Note:Center of block to mid bench is correct distance. ZMID option is needed.


8/22


Page 8

The reason for this is to take into account that in bench composites, although composites are stored at the toe or the mid

bench, they represent the grade of the whole bench. Therefore, the distance to the block needs to be measured from the

center of the composite interval to the center of the block (or from the toe of the composite to the toe of the block; see

figure 8).

Figure 8. Composite Stored at Toe.

Note: Toe to toe is correct distance. No need for ZMID option.


9/22

Page 9


If fixed length composites are used, use the center of the block for distance measurements (see figure 9).

Figure 9. Composite Stored at Mid Bench.

Note: Center of block to mid-bench is correct distance. ZMID option is needed.

Without the mid-bench option, programs will calculate distance from toe of block. If the mid-bench option is used,

programs will calculate the distance from the center of the block.


10/22


Page 10

6. Closest Distance Checking After Versus Before Geologic Matching

Figure 10. Panel for Geologic Matching

Assume the following composites fall within the search parameters:

#etisopmoC eulaVehtotecnatsiD

kcolBepyTkcoR

1 05.0 05 1

2 05.1 06 2

3 50.0 07 2

4 55.0 08 1

5 05.5 09 1

6 57.0 001 2

If you want to use block rock type = 2, max # of composites allowed = 3, and max distance to the closest composite =

55 , if you use the option above the block will not be interpolated.


11/22

Page 11


7. Rotation Changes

Primary search distances are with respect to model coordinates (see figure 11)

Figure 11. Primary Search in a Model Rotated 45 degrees

Options for angles in variograms and ellipses recently added to accommodate the model rotation updates include:


12/22


Page 12

1. Variogram rotation angles can be defined with respect to Project Coordinates or Model Coordinates (see figure 12).

Figure 12. Panel for Variogram Rotation Angles


13/22

Page 13


2. Search rotation angles can also be defined with respect to Project Coordinates or Model Coordinates (see figure

13).

Figure 13. Panel for Search Model Rotation Option


14/22


Page 14

8. Octant/Quadrant Searches

An octant/quadrant search can now be defined with respect to project axes or anistropic axes (see figures 14, 15 and 16).

Figure 14. Panel for Anisotropic Octant/Quadrant Options

Figure 15. Quadrant Search in Project Axes


15/22

Page 15


Figure 16. Quadrant Search in Anistropic Axes


16/22


Page 16

9. Alternative Coordinate Items

The composite coordinate items are used to determine the position of composites in space. The default coordinate items

retrieved from the composite file are EAST, NORTH, ELEV. (3-D Block Models). You can now optionally use other

composite items such as XBOT, YBOT, and ZBOT (see figure 17).

Figure 17. Panel for Optional Coordinate Items


17/22

Page 17


10. Outliers

The maximum search distance can be changed for these composites greater or smaller than a specified cutoff. See

figure 18.

Figure 18. Panel for Outliers

PAR31 = Outlier cutoff to change the search distance

PAR32 = Max 3-D distance for outliers

This means that composites greater than PAR31 will be included in the calculation only if the distance to the block is

less than PAR32. If PAR32 is negative, then the outlier high grades are cut-down to PAR31.PAR33 = Low Grade cutoff to change the search distance

PAR34 = Max 3-D distance for low grades

This means that composites less than PAR33 will be included in the calculation only if the distance to the block is

less than PAR34.

All of the above logic was added to both the kriging and inverse distance programs.


18/22


Page 18

11. Variograms in MineSight3-D

In MineSightCompass, you can run procedure PVGCTR.DAT to create a 2-D contour map of variogram values. If

you want to see those contours in MineSight3-D and use colors for different variogram values you can load them to a

grided surface (file 13 item). You can then make a colored MineSight3-D model view of the variogram values.

Procedure PVGCTR.DAT outputs an ASCII points file (x, y coordinates along with the variogram values). This file can

be loaded to file 13 within the procedure (see figure 19). You need to have a file 13 item with the appropriate minimumand maximum variogram values. If you normalize the values before contouring, the maximum value of the item needs to be

100.

Figure 19. Panel for Variogram Contours


19/22

Page 19


After you run the procedure, create a file 13 view in MineSight3-D. The best way to view the contours is on a -90

degrees dip view with the viewer lights off (see Figure 20).

Figure 20. Variogram Contours in MineSight 3-D

12. Composite Data Distance Analysis

Mintec now has a new program to perform composite data distance analysis to be used in, among other things, theinterpolation search strategy. Procedure P52201.DAT can be found under group composites/operation calculations.

On the following pages is a sample report and a graph of bench elevation per average distance:


20/22


Page 20

Sample Report

Composite Data Distance Analysis by Bench

Based on the Specified Search WindowMoving From Point to Point:

Max. Search Distance: PAR4 = 100.0

Max. No. of Data Points = 8

Available Data Distance Analysis

Bench No. of Item Nearest Average

Toe Data Average Distance Distance

2660.0 4 0.447 40.86 60.94

2645.0 30 0.193 39.30 68.41

2630.0 73 0.333 42.05 69.65 2615.0 81 0.554 41.31 67.97

2600.0 58 0.698 46.52 72.88

2585.0 49 0.610 47.90 75.74

2570.0 48 0.585 50.92 76.89

2555.0 44 0.755 50.77 76.00

2540.0 45 0.798 50.47 75.71

2525.0 48 0.700 50.86 75.22

2510.0 50 0.753 51.82 75.00

2495.0 50 0.760 52.18 74.62

2480.0 47 0.799 52.00 74.43

2465.0 38 0.831 52.76 76.31

2450.0 33 0.803 53.54 77.17

2435.0 26 0.848 52.36 75.31

2420.0 25 0.733 49.53 76.35

2405.0 28 0.799 47.39 74.77

2390.0 28 0.811 45.27 73.40

2375.0 26 0.825 44.55 72.80

2360.0 12 0.723 52.97 74.64

2345.0 8 0.731 51.79 74.60

TOTAL 851 0.670 48.19 73.68


21/22

Page 21


Figure 21. Bench Drillhole Spacing Analysis

13. Multiple Indicator Kriging Program Using GSLIB Routines.

Mintec now has a new Multiple Indicator Kriging program using the GSLIB routines. One advantage of this programover the standard M624IK is the user can specify the extrapolation type assumed at either end of the distribution. In

M624IK, only the linear extrapolation is assumed. The program can be found in the MineSightCompass menu under

group MIK.


22/22


210123348 Interpolation Features and Options

Documents

Transcript of 210123348 Interpolation Features and Options