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Loading this Extension: Spatial Tools is an ArcView program extension which must be run simultaneously with Spatial Analyst. After downloading, unzip the .avx file directly (or unzip to a temp directory, then copy) to the ArcView EXT32 folder. Start the ArcView program, click on "file" and go to "extensions". From the list of available extensions, select Spatial Analyst, then Spatial Tools and click "ok". The collection of new functions will now be available through menu choices, tools, and buttons described below. When installing version 3.2 (10/99), Spatial Analyst will automatically load after selecting the Spatial Tools 3.2 extension.
Note...you must install the g2i.dll file in to the $AVBIN directory (which is now included in the latest version, v. 3.2).
Using this documentation: Click on the menu bar above to go to the major headings and then click on either the subheading list or the image map of menu choices or buttons. Click on the return button to get back to the subheading list.
For any questions or problems
regarding this documentation, contact elizabeth_solomon@nps.gov.
 Introduction |
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Spatial tools is an ArcView extension which provides a collection of grid tools made available through the program's GUI (Graphical User Interface). Menus, Tools, and buttons provide access to various spatial modeling and analysis capabilities such as geometric transformations, mosaicking, resolution alteration, data clean-up and spatial analysis. Spatial Analyst must be loaded simultaneously.
Requirements: ArcView and Spatial Analyst. This program will work in versions of ArcView on PC, UNIX and Macintosh hardware. On the PC platform it is recommended that a Pentium or Pentium Pro 200 or faster be used with this program and at least 32 megabytes of memory, since Spatial Analyst must be running simultaneously.
Other grid operations and
functions not currently available through Spatial Analyst or Spatial Tools
menus can be accessed through the use of the additional extensions and
Avenue Requests. Help for these requests and extensions can be found
in the ArcView On-Line Help Documentation and/or at http://www.esri.com/.
| Hydrologic
Modeling Extension (v1.1)
Flow Accumulation Flow Direction Flow Length Delineate Watershed Area/Perimeter/Length of watersheds Focal Flow Snap Pour Point Stream Order Identify/Fill Sinks Flow Length by Watershed Shape Factor by Watershed Centroid as Point Shape Pour Points as Point Shape Mean Watershed Elevation/Slope/CurveNumber/Precipitation Visibility Extension
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Other Avenue Requests
Flip Mirror Shrink Expand CostDistance CostPath ReturnCostPath Curvature Lookup BlockStats Focal Stats Slice ZonalFill |
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| Data
Format |
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The majority of functions in Spatial Tools operate primarily on grid theme data (ARC GRID format). The exceptions are the Profile and Profile with Feature Points operations which require a combination of active grid, line and point feature themes, and Clip Grid, which requires a selected graphic object as well as an active grid theme to perform the analysis. The menu choices Set to View and Set from View each require a separate existing view in the project and the Type in to Link and Type in from Link work with an existing table (which can be created using the Create Link Table option).
Menu choices are performed
on selected (active) feature themes, after which the user is prompted to
enter or select from a list of variables. Tool buttons are utilized
by clicking the tool and then clicking in the view to perform the function.
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| Views |
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Select a Menu Item
Addition to Version 3.2 menu (10/99):
Changes to Version 3.0 menus include the following:
has been added to the view.
has been added to the view.
has been changed.
Select a Tool
In the following example, 3 grids were mosaiced to create a new grid with smooth boundaries.
Select graphic object
Choose "clip inside" or "clip
outside'
The following set of tools
are used in the georeferencing/warp operation for grid data sets:
Note...Online help for the
warp procedure is available from ArcView's Help Menu
Set
From View
Specifies the view to be
used as the From View in the Warp operation.
Set
To View
Specifies the View to be
used as the To View in the warp operation.
Set
Link Table
Specifies the Table to be
used as the Link Table (a table containing "from" and "to" link coordinates)
in the warp operation.
Create
Link Table
Creates (and sets) an empty
Link Table to be used in the warp operation.
Type
in From Link
Allows the user the option
to manually type in a "from" link coordinate in to the Link Table instead
of clicking in the "From View".
Type
in To Link
Allows the user the option
to manually type in a "to" link coordinate into the Link Table instead
of clicking in the "To View".
Warp
Starts the warp calculation
on an active grid theme. After creating/setting the "From" and "To"
views, creating/setting the link table, and building a list of coordinates
in the table, the user must select the "From View", and is prompted to
enter the polynomial order to be used, as well as the desired resampling
method (Nearest Neigbor, Bilinear, or Cubic Convolution).The new dataset
will be added to the "to" view and named "Warp of (original grid theme)".
The following bathymetry grid was aggregated using maximum values for depth and a cell factor of 3. The resulting grid been resampled to a coarser resolution.
Takes a grid or set of grids
that were created from a true color image and converts them into a BSQ,
BIL, BIP, JPG or TIFF image.
All of the grids must be
from the same source image and must be of the integer type. Cell
values cannot exceed 255.
The g2i.dll file must be placed into the bin32 directory to work properly.
In the following example,
the majority filter function has smoothed out the data by replacing misclassified
cells (dark green areas of vegetation occurring in water) with new values
using the most frequently occurring values of neighboring cells.
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In the following landcover grid, the original values which represent "shadows" (displayed in black) were set to to No Data by entering a count of 1500. The new grid represents the original values for all data with a count greater than 1500.
notBinary (TRUE = all values
other than No Data are thinned. FALSE = only values greater
than 0 are thinned).
doFilter (TRUE = the
Grid is filtered to smooth the boundaries between values. FALSE = no filter
is used).
sharpenCorners (TRUE = rectangular
corners and junctions are preserved. FALSE = all corners and junctions
are smoothed).
maxThickness (can be a Number
or Nil, that defines the maximum thickness, in map units, of linear features
in the Grid. If maxThickness is set to Nil a value 10 times the cell size
of aGrid is used).
Changes the resolution of the active grid by interpolating values using a chosen resampling method (nearest-neighbor, bilinear, or cubic).
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Random
Grid
This function creates a
random grid. The user selects either a uniform random or a normal
random grid, and is prompted as to whether or not the values are to be
adjusted.
The following histograms
illustrate the default values used in creating uniformly and normally
distributed random grids:
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| Uniform: Values are between 0 and 1 | Normal: Mean = 0 and Standard Deviation = 1 |
Pycnophylactic
Interpolation
The program performs pycnophylactic
interpolation on a categorical grid.
The analysis variable in
the VTAB of the grid should represent a phenomenon that changes continuously
over space.
Creates a table containing various geometric calculations for each zone in the active grid.
In this example, the selected
stream (shown highlighted in yellow) was profiled, using 5 equal divisions.
The chart below shows distance and corresponding elevation values.
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Used to create elevation
profiles of selected lines and selected point features. Requires
three active themes, the first a point theme (the feature points), the
second a line theme and the third an elevation grid theme.User is queried
for how many divisions of merged line. Outputs a dbf file of distances
starting at the lowest inerval point and including all interval points,
feature points and corresponding z values. Dbf table contains a "Type"
field indicating whether a distance is an interval point or a feature point.
Outputs a scatter diagram graph (the line profile) of distance from origin
vs. z values if no more than baout 50 points are produced.
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Conducts a visibility analysis of a line or point file. This function requires the following fields in the input FTab, which are used to control the visibility analysis. These Fields are SPOT, OFFSETA, OFFSETB, AZIMUTH1, AZIMUTH2, VERT1, VERT2, RADIUS1 and RADIUS2.
If not specified, the default
values in the Visibility Tool are are set as follows:
| SPOT | INTERPOLATED FROM THE INPUT GRID |
| OFFSETA | 1 |
| OFFSETB | 0 |
| AZIMUTH1 | 0 |
| AZIMUTH2 | 360 |
| VERT | 90 |
| VERT2 | -90 |
| RADIUS1 | 0 |
| RADIUS2 | INFINITY |
Creates
Warp start points (creates a "from link" in the "from" view).
Click on a location in the ungeoreferenced dataset to start building a
list of "from links" (Points will automatically be labelled). Use
the delete links button to remove incorrect
links from the table.
Creates
Warp desired points (creates a "to link" in the "to" view). Click
on the desired location in the georeferenced dataset to start building
a list of "to links" (Points will automatically be labelled). Use
the delete links button to remove incorrect
links from the table.
Shifts
the active grid to a new location by clicking in the view to move
its point of origin.Click the tool, then click on the desired location
to shift to in the view.
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Deletes
one or many links from the current link table.
Click the button, then select
one or many links to delete from the table.
Rotates
the active grid in a clockwise motion around the lower left-hand corner.
Click the button, then enter the number of degrees desired (and the resampling method to be used if multiples of 90 degrees are not used). (See previous section on Resampling methods, for a description of the 3 types of interpolation).
In this example, a new grid
was created, rotated 90 degrees around the original grid's lower laft-hand
corner.
| Bibliography |
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