Tools

From OpenJUMP Wiki
Revision as of 05:22, 9 November 2009 by Mentaer (talk | contribs)
Jump to navigation Jump to search

Back to List of Functions


This paragraph is only a brief description of the functions in Tools Menu. The reading of VIVID SOLUTIONs JUMP Workbench User's Guide and Uwe Dallueges OpenJUMP 1.0.1 Basics Tutorial – is recomended for better explanation)


Queries

Users can customize queries on an opened project. Results can be selected and/or saved to a new layer.

  • Queries
    • Spatial Query... - Spatial Query works between two layers. It is possible to find spatial relationship (intersects, contain...) of the working layer (source layer) compared to another layer (mask layer).
    • Attribute Query... - This query works inside a Source layer. User can find datas with attributes which satisfied given conditions (ex. Area or Line equal or more than a numeric value).
    • Simple Query... - This function open a Query Builder window where users can define more query on their layers. Datas can be filtered according to their attribute type (String, Numeric or Geometric). Queries can be done either on a single layer or on more layers. More function (lenght, surface, buffer ...) can be defined with operators.
    • Search All Attributes... - This function searches for a text in all layers.

Analysis

Geometrical analysis of features. Results are usually saved to a new layer.

  • Analysis
    1. One Layer - these tools allow to do geometrical analysis of features in a single layer
      • Union... - This function create a new layer (layer Union) containing the union of all the feature of the selected layer.
      • Calculate areas and lengths.. - This function calculate areas and lenghts of selected features in a layer. The layer must be editable.
        TIP: to calculate the area or the lengh of a layer: create a new attribute field (ex. "Area") on the working layer. Make the working layer editable (Layer List Menu>Editable), on Tools>Analysis... select Calculate areas and lenghts.., select the layer and the Area attribute field and click OK. The new Area attribute field will be populated with the area values (in meters) of the selected layer
      • Join Attributes Spatially... - Join attributes of a source layer according to a spatial and a statistical criterion
      • Union by attribute value - Create a new layer with all the features. Features which have a common attribute value will be union in one feature
    2. Two Layers - these tools allow to do geometrical analysis of features between two layers
      • Overlay - This function calculates the intersection between two layers. A new layer is created with the intersected features of the two layers. Attributes can be transfered from one of the souce layers.
      • Spatial Join of Geometries... - It is possible to join two layers on a given spatial relationship (ex. create a new layer where features of the Source intersect Mask, or contains, etc.). Joined layers are saved on a new _Join-.. layer
        a) If layer A=buildings, spatial operation= intersect, layer B = landparcels, then it takes objects from Layer B as source (landparcels) and adds attributes from Layer A (buildings). The returned landparcels appear as often as buildings are inside them to ensure all attributes are transfered.
        b) If a=parcels, spatial op=intersect, b=buildings then it return all buildings with the attributes from the underlying parcel.
      • Intersect Polygon Layers - This function intersects the features of two layers that both must contain polygons. The results are saved in a separate layer with the attributes of the original layers


Statistics

  • Statistics
    • Layer Attribute Statistics - Calculates statistical indices such as Minimum value, Maximum value, Mean vealue, standard deviation and sum value for all attributes and all features in a layer. Layer statistics will be displayed in a output window.
    • Layer statistics - Users can obtain basic statistics (e.g. area, number of vertices, etc.) of the features in a layer. Layer statistics will be displayed in a output window.
    • Feature statistics - Users can obtain basic statistics (e.g. area, number of vertices, etc.) of the features in a layer. Layer statistics will be saved as attributes in a new layer.


Generate

  • Generate
    • Buffer... - This function creates a buffer in all geometries in the selected layer. In the OpenJUMP Nightly Build, buffer tool provides a convenience union option. Sidebar picture previews the current options. It copies attributes bydefault, even from selections on multiple layers, but this can beturned off. Supports setting the number of segments in a quarter circle.
    • Convex Hull on Layer... - It creates a new layer with the Convex Hull of all the features of a layer (Convex Hull is basically a linestring which contains al the features)
    • Create Thiessen polygon - This function creates a Delaunay triangolation and returns the Voronoi regions of all the point features of a layer
    • Convex Hull - This function creates a Convex Hull which contains selected features of one o more layers. The convex hull is saved in a new layer (Convex Hull layer)
    • Multiple Ring Buffer - This tool creates a class of buffer features using a set of buffer distances. Unlike normal buffers, the new features do not overlap the inner areas. When multiple features are selected, the equal distance Ring Buffers from each feature are unioned.
      The Buffer options provided are: Buffer number of features, Buffer distance of the other buffer feature, Bufer label of the inner buffer feature
    • Plume... - This tool create a Plume buffer from a selected line. The user can define the radius of the two end points of the line
    • Random triangles - This function creates a new layer (Random triangles) and populates it with random triangle polygons.
    • Random arrows - A new layer is created and populated with random arrows


Warp

OpenJUMP can warp vector layers. Warping modifies all the features in a selected layer according to some specified parametres, like vectors. please see also the good documentation in VIVID SOLUTIONs Jump Workbench User's Guide, page 41 to 43.

  • Warp
    • Warping - It opens the warping window. Users can select, draw and delete vectors, can display triangulation and choose other warping functions.
    • Affine transformation - After defining vectors, this function warp the selected ap'playing an Affine transformation. Usually only three points (vectors) are useful to define the affine transformation.
    • New Affine Transformation... - This function applies an affine trasformation to all the features in a layer. Compared to Warp function, with the New Affine Tranformation it is possible to set the coordinate of the Anchor Point. The transformation is specified by some factors like: Scaling. Rotating, Shearing and Translation. Transformation parametres can be computed from two layers containing baseline vectors

QA

Quality Assurance tools to make advanced spatial operations to analyze features in a layer. Results are saned in a layer in See VIVID SOLUTIONs Jump Workbench User's Guide, page 37 to 40 for better explanation.

  • QA
    • Validate Selected layers - These tools are used to validate the topology of the features. In the validation dialog Users can select check for topology errors or define simple geometrical queries.
    • Calculate Geometry Difference... - This function finds differences between geometries or segments in two layers
    • Delete Empty Geometries in Selection - Users can delete empty geometries in selected features.
    • Delete Duplicate Geometries... - Users can delete geometries that appear twice ore more time in a layer.

Edit Geometries

The Edit functions provides more editing tools for the geometries in a layers. The results are saved in a new layer.

  • Edit Geometries
    • Convert
      • Extract Points - allows to extract vertices from lines or polygon and save them in a new layer as points
      • Extract common boundary between polygons... - Users can extract all boundaries from polygons. Where polygons touch only one boundary (line) is extracted.
      • Extract segments... - Users can extract all segmets from a layer. Some extra option are provided with this function: doubled segments can be eliminated and the resulting segments can be merged.
      • Polygonize... - all the enclosed areas inside crossed lines can be transformed in polygons. Optionally input data may be noded before polygonization.
      • Planar Graph - This function does a topologic analysis (calculate nodes, fence and their relation with arcs). Results are saved in separates layers with the same attributes of the original layer.
    • Geometry functions... - Special geometric functions (Union, Difference) can be set on a source layer comparing to another layer (mask layer). It is also possible to create centroids of the source layer. Results can be also be added to the source layer.
    • Node-Lines... - Users can extract segments from a layer or from selected features. The croosed point of two lines are transformeìd in nodes, the result lines are interrupted at the nodes.
    • Precision Reducer - This function reduces the precision of coordinates in a layer
    • Join-With-Arc - Two selected lines can be joined with an arch. Arc radius can be specified. This function works only with two lines, not with other geometrical features (points or polygons)
    • Blend Lines - Two or more lines which are in contact in a node can be blended in a new line. Users can choose the tolerance of the blend action. usually a tollerance between 1 to 10 is quite accurate.
    • Merge Two Polygons - Users can merge two o more selected polygons in a layer. Empty area in between of polygons are transformed in donuts.
    • Split Polygon - With this function it is possible to cut one o more polygons in a layer. Cut polygon can be saved in a new layer or upgraded to the source one. To cut a Polygon: draw a linestring which cross the polygon exactly over the points you want to cut. Select both polygon and line. Click on Cut Polygons.
(Geometry function can alternate the original attribute value of features (ex. in Blend Polygons). New geometries created in new layers (ex polygonize or Node-Lines do not have attributes. Users must edit the new feature to set attributes)

Edit Attributes

These functions allow user to edit, modify and perform calculation on attributes from layer. Some tools work only on Editable layers.

  • Edit Attributes
    • Transfer Attributes - Users can transfer attributes from a source layer to a target layer using spatial criterion (equal, within, equal AND within, equal OR within)
    • Auto Assign Attribute - Users can assign a value on a fiield from an attribute or set an auto-incremental number or a combination of a value and an auto-incremental number .
    • Attribute Calculator - This function lets Users perform simple calculation on the records. User can choose type type and formulas. The tool create automatically a new field on the attribute table of the layer
    • Join CSV table - Users can inport datas from a .TXT or .TEXT file into a layer. New datas must have a Tab delimitated format (Note, the Pirol CSV plugin has advanced table reading functions, e.g. to import points from CSV files).

Generalization

These functions mostly simplify a selected line or a polygon. Depending on the input data, two different tools are available:

  • Generalization
    • Simplify (JTS algorithm) - line simplification with the Douglas-Peucker algorithm.
    • Simplify Polygon Coverage - polygon outline simplification with the Douglas-Peucker algorithm that can be applied to a polygon layer. The algorithm tries to avoid that simplified lines overlap. However, if this happens a smaller simplification value must be chosen.
Note, more generalization tools (expecially for building generalization) are available in a special toolbox.

Misc

  • Measure in Feet - This function allows to measure a distance between two or more points. The distance is displayed both in feet and in metres on the bottom left side of OpenJUMP Workbench window.

<--- back to List of Functions