📄 gslib help kt3d.htm
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<!-- saved from url=(0041)http://www.gslib.com/gslib_help/kt3d.html -->
<HTML><HEAD><TITLE>GSLIB Help: KT3D</TITLE>
<META http-equiv=Content-Type content="text/html; charset=gb2312">
<META content="MSHTML 6.00.2900.2627" name=GENERATOR></HEAD>
<BODY bgColor=#ffffff><IMG height=8 alt=---
src="GSLIB Help KT3D.files/line.blue.gif" width=652>
<P>
<CENTER>
<H2>GSLIB Help Page: KT3D</H2></CENTER>
<DL>
<DT><IMG height=14 alt=o src="GSLIB Help KT3D.files/ball.red.gif" width=14>
<STRONG>Description:</STRONG>
<UL>
<LI>The program <TT>kt3d</TT> provides a fairly advanced 3-D kriging program
for points or blocks by simple kriging (SK), ordinary kriging (OK), or
kriging with a polynomial trend model (KT) with up to nine monomial terms.
The program works in 2-D and is faster than <TT>kb2d</TT> if there are many
data. One of the features that makes this program fairly fast is the super
block search. </LI></UL>
<DT><IMG height=14 alt=o src="GSLIB Help KT3D.files/ball.red.gif" width=14>
<STRONG>Parameters:</STRONG>
<UL>
<LI><B>datafl:</B> the input data in a simplified Geo-EAS formatted file.
<LI><B>icolx, icoly, icolz, icolvr</B> and <B>icolsec:</B> the columns for
the <I>x, y,</I> and <I>z</I> coordinates, the variable to be estimated, and
the external drift variable (or non-stationary mean).
<LI><B>tmin</B> and <B>tmax:</B> all values strictly less than <B>tmin</B>
and greater than or equal to <B>tmax</B> are ignored.
<LI><B>option:</B> set to 0 for kriging a grid of points or blocks, to 1 for
cross validation with the data in <B>datafl</B> and to 2 for jackknifing
with data in following file.
<LI><B>jackfl:</B> file with locations to perform estimation (jackknife
option).
<LI><B>icolx, icoly, icolz, icolvr</B> and <B>icolsec:</B> the columns for
the <I>x, y,</I> and <I>z</I> coordinates, the variable, and the secondary
variable in <B>jackfl</B>
<LI><B>idbg:</B> an integer debugging level between 0 and 3. The higher the
debugging level the more output. The normal levels are 0 and 1 which
summarize the results. Levels 2 and 3 provide all the kriging matrices and
data used for the estimation of every point/block. It is recommended that a
high debugging level not be used with a large grid.
<LI><B>dbgfl:</B> the debugging output is written to this file.
<LI><B>outfl:</B> the output grid is written to this file. The output
contains the estimate and the kriging variance for every point/block on the
grid, cycling fastest on <I>x</I> then <I>y</I> and finally <I>z</I>
Unestimated points are flagged with a large negative number (-999.). The
parameter UNEST, in the source code, can be changed if a different number is
preferred.
<LI><B>nx, xmn, xsiz:</B> definition of the grid system (<I>x</I> axis).
<LI><B>ny, ymn, ysiz:</B> definition of the grid system (<I>y</I> axis).
<LI><B>nz, zmn, zsiz:</B> definition of the grid system (<I>z</I> axis).
<LI><B>nxdis, nydis</B> and <B>nzdis:</B> the number of discretization
points for a block. If <B>nxdis, nydis</B> and <B>nzdis</B> are all set to 1
then point kriging is performed.
<LI><B>ndmin</B> and <B>ndmax:</B> the minimum and maximum number of data
points to use for kriging a block.
<LI><B>noct:</B> the maximum number to retain from an octant (an octant
search is not used if <B>noct=0</B>
<LI><B>radius_hmax</B> <B>radius_hmin</B> and <B>radius_vert</B> the search
radii in the maximum horizontal direction, minimum horizontal direction, and
vertical direction (see angles below).
<LI><B>sang1, sang2</B> and <B>sang3:</B> the angle parameters that describe
the orientation of the search ellipsoid. See the discussion on anisotropy
specification associated with Figure II.4.
<LI><B>ikrige</B> and <B>skmean:</B> if <B>ikrige</B> is set to 0 then
stationary simple kriging with (<B>skmean</B>) will be performed, if
<B>ikrige</B> is set to 1 then ordinary kriging will be performed, if
<B>ikrige</B> is set to 2 then non-stationary simple kriging with means
taken from <B>secfile</B> will be performed, and if <B>ikrige</B> is set to
3 then kriging with an external drift will be performed. Note that power law
variogram models (<B>it</B>=4) are not allowed with simple kriging.
<LI><B>idrif(i),i=1...9:</B> indicators for those drift terms to be included
in the trend model. <B>idrif(i)</B> is set to 1 if the drift term number
<I>i</I> should be included, and is set to zero if not. The nine drift terms
correspond to the following:
<UL>
<LI><B>i = 1</B> linear drift in x
<LI><B>i = 2</B> linear drift in y
<LI><B>i = 3</B> linear drift in z
<LI><B>i = 4</B> quadratic drift in x
<LI><B>i = 5</B> quadratic drift in y
<LI><B>i = 6</B> quadratic drift in z
<LI><B>i = 7</B> cross quadratic drift in xy
<LI><B>i = 8</B> cross quadratic drift in xz
<LI><B>i = 9</B> cross quadratic drift in yz </LI></UL>
<LI><B>itrend:</B> indicator of whether to estimate the trend (<B>itrend</B>
=1) or the variable (<B>itrend</B> =0). The trend may be kriged with
ordinary kriging (all <B>idrif(i)</B> values set to 0) or with any
combination of trend kriging (some <B>idrif(i)</B> terms set to 1).
<LI><B>secfl:</B> a file for the gridded external drift variable. The
external drift variable is needed at all grid locations to be estimated. The
origin of the grid network, the number of nodes, and the spacing of the grid
nodes should be exactly the same as the grid being kriged in <TT>kt3d</TT>
This variable is used only if <B>ikrige</B>=2 or 3.
<LI><B>iseccol:</B> the column number in <B>secfl</B> for the gridded
secondary variable. This variable is used if <B>ikrige</B>=2 or 3.
<LI><B>nst</B> and <B>c0:</B> the number of variogram structures and the
nugget constant. The nugget constant does not count as a structure.
<LI>For each of the <B>nst</B> nested structures one must define <B>it</B>,
the type of structure; <B>cc</B>, the <I>c</I> parameter;
<B>ang1,ang2,ang3</B>, the angles defining the geometric anisotropy;
<B>aa_hmax</B>, the maximum horizontal range; <B>aa_hmin</B>, the minimum
horizontal range; and <B>aa_vert</B>, the vertical range. </LI></UL>
<DT><IMG height=14 alt=o src="GSLIB Help KT3D.files/ball.red.gif" width=14>
<STRONG>Application notes:</STRONG>
<UL>
<LI>The program is set up so that a novice programmer can make changes to
the form of the polynomial drift. The external drift concept has been
incorporated, adding an additional unbiasedness constraint to the ordinary
kriging system. When using an external drift, it is necessary to know the
value of the drift variable at all data locations and all the locations that
will be estimated (i.e., all grid nodes).
<LI>The program also allows simple kriging with non-stationary means read
from an input file. The non-stationary means must be known at all data
locations and all locations to be estimated. </LI></UL></DT></DL><IMG height=8
alt=--- src="GSLIB Help KT3D.files/line.blue.gif" width=652>
<P></P></BODY></HTML>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -