GridData

The GridData method is superseded by GridData6. Please consider using the more recent version. GridData has been retained for backward compatibility.

GridData creates a grid from irregularly spaced XYZ data. Grid files are required to create different types of maps, including contour, image, shaded relief, vector, 3D surface, and 3D wireframe. The grid data files are typically randomly spaced files, and this data must be converted into an evenly spaced grid before using. GridData returns a Boolean value. It returns 'True' if the grid file is successfully created, otherwise returns 'False'.

The GridData2 command should specifically be used instead of GridData when the worksheet being loaded is an Excel file where the sheet name needs to be specified. It can also be used to specify any data import options when loading a data file.

Syntax

object.GridData( DataFile, xCol, yCol, zCol, ExclusionFilter, DupMethod, xDupTol, yDupTol, NumCols, NumRows, xMin, xMax, yMin, yMax, Algorithm, ShowReport, SearchEnable, SearchNumSectors, SearchRad1, SearchRad2, SearchAngle, SearchMinData, SearchDataPerSect, SearchMaxEmpty, FaultFileName, BreakFileName, AnisotropyRatio, AnisotropyAngle, IDPower, IDSmoothing, KrigType, KrigDriftType, KrigStdDevGrid, KrigVariogram, MCMaxResidual, MCMaxIterations, MCInternalTension, MCBoundaryTension, MCRelaxationFactor, ShepSmoothFactor, ShepQuadraticNeighbors, ShepWeightingNeighbors, ShepRange1, ShepRange2, RegrMaxXOrder, RegrMaxYOrder, RegrMaxTotalOrder, RBBasisType, RBRSquared, OutGrid, OutFmt, SearchMaxData, KrigStdDevFormat, DataMetric, LocalPolyOrder, LocalPolyPower, TriangleFileName )

Parameter

Type

Required/

Optional

Default

Description

DataFile

String

Required

 

This provides the path and file name of the XYZ data file name

xCol

Long

Optional

1 (Column A)

This provides the column containing X values, column A = 1.

yCol

Long

Optional

2 (Column B)

This provides the column containing Y values, column B = 2.

zCol

Long

Optional

3 (Column C)

This provides the column containing Z values, column C = 3.

ExclusionFilter

Variant

Optional

 

This provides the Boolean search to exclude values.

DupMethod

Variant

Optional

 

This provides the method for eliminating duplicates, the SrfDupMethod enumeration can be used for this parameter.

xDupTol

Variant

Optional

 

This provides the separation distance of X values to be considered duplicates.

yDupTol

Variant

Optional

 

This provides the separation distance of Y values to be considered duplicates.

NumCols

Variant

Optional

 

This provides the grid line geometry number of columns.

NumRows

Variant

Optional

 

This provides the grid line geometry number of rows.

xMin

Variant

Optional

 

This provides the grid line geometry minimum X value.

xMax

Variant

Optional

 

This provides the grid line geometry maximum X value.

yMin

Variant

Optional

 

This provides the grid line geometry minimum Y value.

yMax

Variant

Optional

 

This provides the grid line geometry maximum Y value.

Algorithm

Variant

Optional

 

This provides the gridding method (kriging, etc.), the enumeration can be used for this parameter.

ShowReport

Variant

Optional

 

This enables the show grid report, the report is only shown if ShowReport is true and Surfer is visible.

SearchEnable

Variant

Optional

 

This enables No Search (use all of the data). It is one of the search options.

SearchNumSectors

Variant

Optional

 

This provides the number of sectors to search.

SearchRad1

Variant

Optional

 

This provides the search ellipse radius 1. It is one of the search options.

SearchRad2

Variant

Optional

 

This provides the search ellipse radius 2. It is one of the search options.

SearchAngle

Variant

Optional

 

This provides the search ellipse angle. It is one of the search options.

SearchMinData

Variant

Optional

 

This provides the minimum number of data in all sectors (node is blanked if the data surrounding the node are less than this number).

SearchDataPerSect

Variant

Optional

 

This provides the maximum number of data to use from each sector.

SearchMaxEmpty

Variant

Optional

 

This provides the number of blank nodes if more than this many sectors are empty.

FaultFileName

Variant

Optional

 

This provides the file containing fault traces.

BreakFileName

Variant

Optional

 

This provides the file containing breaklines.

AnisotropyRatio

Variant

Optional

 

This provides the anisotropy ratio used for various algorithms.

AnisotropyAngle

Variant

Optional

 

This provides the anisotropy angle used for various algorithms.

IDPower

Variant

Optional

 

This specifies the inverse distance to a power, power number.

IDSmoothing

Variant

Optional

 

This specifies the inverse distance to a power, smoothing factor.

KrigType

Variant

Optional

 

This specifies the kriging type (point or block. The enumeration can be used for this parameter.

KrigDriftType

Variant

Optional

 

This specifies the kriging drift type (none, linear, or quadratic), the enumeration can be used for this parameter.

KrigStdDevGrid

Variant

Optional

 

This provides the output grid of kriging standard deviations

KrigVariogram

Variant

Optional

 

This specifies the kriging variogram model. KrigVariogram may contain an array of VarioComponent objects. If this parameter is not specified the default Linear variogram is used.

MCMaxResidual

Variant

Optional

 

This specifies the minimum curvature maximum residual.

MCMaxIterations

Variant

Optional

 

This specifies the minimum curvature maximum number of iterations.

MCInternalTension

Variant

Optional

 

This specifies the minimum curvature internal tension factor.

MCBoundaryTension

Variant

Optional

 

This specifies the minimum curvature boundary tension factor.

MCRelaxationFactor

Variant

Optional

 

This specifies the minimum curvature relaxation factor.

ShepSmoothFactor

Variant

Optional

 

This specifies the modified Shepard's method smoothing factor.

ShepQuadraticNeighbors

Variant

Optional

 

This specifies the modified Shepard's method quadratic neighbors.

ShepWeightingNeighbors

Variant

Optional

 

This specifies the modified Shepard's method weighting neighbors.

ShepRange1

Variant

Optional

 

This specifies the modified Shepard's method anisotropy range 1.

ShepRange2

Variant

Optional

 

This specifies the modified Shepard's method anisotropy range 2.

RegrMaxXOrder

Variant

Optional

 

This specifies the polynomial regression maximum X order.

RegrMaxYOrder

Variant

Optional

 

This specifies the polynomial regression maximum Y order.

RegrMaxTotalOrder

Variant

Optional

 

This specifies the polynomial regression maximum total order.

RBBasisType

Variant

Optional

 

This specifies the radial basis function type (inverse multiquadric, multilog, multiquadric, natural cubic spline, or thin plate spline), theSrfBasisTypeenumeration can be used for this parameter.

RBRSquared

Variant

Optional

 

This specifies the radial basis function correlation coefficient

OutGrid

String

Optional

""

This provides the path and file name of the output grid file.

OutFmt

SrfGridFormat

Optional

srfGridFmtS7

This provides the output grid file format,

SearchMaxData

Variant

Optional

 

This specifies the maximum number of data to use from all sectors. This one of the search criteria.

KrigStdDevFormat

Variant

Optional

 

This specifies the standard deviation grid file format, theenumeration can be used for this parameter

DataMetric

Variant

Optional

 

This specifies one of thedata metricoptions, the SrfDataMetric enumeration can be used for this parameter.

LocalPolyOrder

Variant

Optional

 

This specifies the local polynomial order.

LocalPolyPower

Variant

Optional

 

This specifies the local polynomial power (0 to 20).

TriangleFileName

Variant

Optional

 

This provides the name of the file to contain the triangulation - the format is determined by the file name extension.

Remarks

Please refer to the gridding advanced options dialogs for more information on using gridding options. Some of the above options require certain parameters to be used and some parameters cannot be used with other parameters. For example, SearchEnable must be enabled to successfully use the seven parameters (Search...) that follow it. Another example is if the natural neighbor gridding method is selected for Algorithm, KrigVariogram should not be set. Since this method contains so many parameters, try using named arguments for this method (see examples below). There is no need to preload the file into the worksheet.

Example 1

This example uses the Kriging method for gridding data.

SurferApp.GridData(DataFile:=SurferApp.Path+"\Samples\demogrid.dat", xCol:=1, yCol:=2, _

zCol:=3, Algorithm:=srfKriging, ShowReport:=True, SearchEnable:=True, _

KrigStdDevGrid:=SurferApp.Path+"\Samples\StdDev.grd, _

OutGrid:=SurferApp.Path+"\Samples\sample1a.grd", OutFmt:=srfGridFmtS7)

Example 2

This script displays all the methods in the Application object.

Used by: Application object