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{alias:grp}
h2. Name

*grp* — Grid points and lines {alias:grp}

h2. Syntax
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*grp* \[*inc*] | \[_nx ny_] | \[*long*] \[*sca*] \[*ref*] \[*csf*] \[*aux*] \[*ssf*] \[*ssfdis*] \[*rad*] \[*trg*] \[*pav*] \[*mav*] \[*exc*] \[*log*] \[*son*] \[*2dc*] \[*nsc*] \[*mnp*] \[*mrf*] \[*cvf*] \[*2d*] \[*fast*] \[*ext*] \[*int*] 

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h2. Description

General gridding command from input points and lines into a grid surface. Default is parabolic interpolation.

h2. Arguments

{indent}No arguments, the grid will have the same number of rows and columns as the last grid that set the @nrow @ncol variables.{indent} 
*inc* _xinc yinc_ 
{indent}Create grid model grid with increments _xinc_ and _yinc_ .{indent} 
_nx ny_ 
{indent}Create a grid with _nx_ times _ny_ grid cells.{indent} 
*long* _num_ 
{indent}Create a grid with _num_ nodes for the longest side. Use the same increment for the shortest side.{indent} 
*sca* 
{indent}Result grid is polydata and the scalars will be gridded in an extra pass and put into the scalar part of the poly grid.{indent} 
*trg* \[*gri*] 
{indent}End up with polydata grid and a triangualtion model toward faults. Make a grid also when gri is given.{indent} 
*ref* _reference\_grid_ 
{indent}Use a reference_grid in workspace to tell the layout of the result grid.{indent} 
*csf* _closed\_stick\_faults_ 
{indent}Use closed_stick_faults in workspace as input to gridding.{indent} 
*aux* _help\_lines_ 
{indent}Help lines to be used together with *csf* option.{indent} 
*ssf* _single\_stick\_faults_ 
{indent}Use _single\_stick\_faults_ traces without values in workspace as input.{indent} 
*ssfdis* _split\_distance_ 
{indent}Optional _split\_distance_ of _single\_stick\_faults_.{indent} 
*rad* _radius_ 
{indent}Use a radius value for max interpolation distance.{indent} 
*pav* 
{indent}Interpolation is a blend of parabolic and moving average.{indent} 
*mav* 
{indent}Moving average is used for interpolation.{indent} 
*smo* _smoothstrength_ 
{indent}Will use smoothing of cube at end of gridding.{indent} 
*exc* \[_value_] 
{indent}Exclude points at grid nodes closer than _value_ to achieve a smoothing effect. If _value_ is omitted only the grid node to be smoothed is excluded and the 8 remaining grid nodes in the 3x3 grid node pattern are used to evaluate the grid node using the parabolic interpolator unless the *mav* argument is used. *grp exc* is often run as an extra smoothing step after the gridding.{indent} 
*log* _log\_number_ 
{indent}List info in message area. Gives a message for each _log\_number_ grid line.{indent} 
*son* 
{indent}Use sonar sorting of input. This is default for size of input points greater than 1000.{indent} 
*2dc* 
{indent}Input is 2D contour lines with values.{indent} 
*2d* 
{indent}Input is 2D lines f.inst. from seismic.{indent} 
*nsc* _number\_of\_sectors_ 
{indent}For sort grid aplication: _number\_of\_sectors_ used in interpolation.{indent}
*mnp* _max\_number\_of\_points_ 
{indent}For sort grid application: _max\_number\_of\_points_ used in interpolation.{indent} 
*cvf* _closed\_value\_faults_ 
{indent}Use _closed\_value\_faults_ traces with values in workspace as input.{indent} 
*fast* 
{indent}Fast gridding. Internal parameters are trimmed to give a fast result.{indent} 
*ext* \[*par | mav*] \[*ref* _referencegrid_]
{indent}
Extrapolate a grid inside the window. Input is a grid. Will use the CMOS algorithm for a smoother extrapolation as default.
*par | mav* - Will use the parabolic or moving average algorithm for faster performance.
*ref* _referencegrid_ - Apply the reference grid _referencegrid_ to tell where the extrapolation should be done.
{indent} 
*int* \[*par*] \[*poi* _points_] \[*cpo* _closedpolygons_] \[*ext*]
{indent}
Interpolate holes in a grid. Input is a grid. Default interpolator is the CMOS algorithm for a smoother interpolation.
*par* - Use parabolic algorithm for quick solution if only very small holes.
*poi* _points_ - Interpolate only holes where a point is present in workspace data _points_. 
*cpo* _closedpolygons_ - Interpolate only holes where a closed polygon is present in workspace data _closedpolygons_. 
*ext* - will first perform interpolation to fill in interior holes; then extrapolation to extrapolate until grid frame.
{indent} 
*mrf* 
{indent}See argument *mrf* in the [son|ref:son - Sonar data gridding] command.{indent}

h2. Examples

h3. Ex.1: Point gridding

{noformat:|borderWidth=1|bgColor=#eeeeee}
mak ran 11      ;# Make 11 random points
grp 50 50       ;# Make a grid of 50 50 nodes
{noformat}

{noformat:|borderWidth=1|bgColor=#eeeeee}
# Point model gridding
z                 ;# Erase screen
win demo          ;# Get demo window (450000 460000 6450000 6460000 1000 4000)
mak ran 22        ;# Make random points
poi               ;# Display points
grp 70 70         ;# Make grid
map               ;# Misplay map
cco map rev tit {Depth} ; # color code type map, reverse color and title
{noformat}

The above example produces this image. 

!att:_img_ref^cmd_grp.png!
_Examples of parabolic gridding_

h3. Ex.2: Interpolation of interior holes

{noformat:|borderWidth=1|bgColor=#eeeeee}
win demo         ;# make demo window
mak ran 222 rngz 1000 4000     ;# Make 222 random points between 1000 and 4000
grp 333 444      ;# Make a grid of 333 x 444 nodes
eli lt 1500      ;# eliminate lower than 1500
mhi gg           ;# save in gg
vie 2 1 1        ;# make 2 x 1 viewports and select the first
acm s 1750 500 4000 ;# color bands starting from 1750 and step by 500
sma i 125        ;# spline contours with increment 125
vie 2 con        ;# select viewport 2 and connect to 1
grp int          ;# grid and interpolate holes
acm s 1750 500 4000 ;# color bands starting from 1750 and step by 500
sma i 125        ;# spline contours with increment 125

{noformat}

The above example produces this image. 

!att:_img_ref^grp_int.png!
_Examples of interpolation of holes using gridding_

h2. See also

[gen - Generate grid], [gr3 - Grid data into 3D cube], [gsu - Grid surface points], [fmo - Fast modelling], [trg - Triangulate point data]
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