SuperMap iDesktopX
    简体中文11.0.1 GitHub
     /
     /
     /
     /

    Dissolve Dataset

    Introduction

    In a line, region or text dataset, the feature can dissolve objects meeting some conditions to one object.

    The following conditions are needed for dataset dissolving:

    • The values of certain fields are the same in the data object.
    • Only the line objects with the same endpoints can be dissolved.
    • The region objects must be intersects or adjacent with each other (have common borders).

    The Dissolve feature includes three dissolving modes: Dissolve, Group and Group after Dissolve. Note : only can Group work on a text dataset.

    • The following picture demonstrates the dissolving effect.

    Datafuse1

    Dissolve the object with the index 1

    The result above shows that the region with the index 1 is dissolved, but not the objects that are not adjacent with each other.

    • The effect of group:

    datagroup

    The object with the index 1 is grouped to a compound object.

    The result above shows grouping several subobjects to a composite object, the intersection part of the object is processed with the XOR computing.

    Function Entrances

    • Data tab > Data Processing > Vector > Dissolve.
    • Toolbox > Data Processing > Vector > Dissolve. (iDesktopX)

    Parameter Specification

    • Source Data : Displays all line and region datasets in the specified datasource. Select the datasets to dissolve.

    • Parameter Settings

      • Pattern : Three dissolve modes are provided.
      • Dissolve : Dissolve the objects which have the same attribute fields and intersects with each other (or the distance between them are within the tolerance) to one object.
      • Group : Group the objects with the same attribute fields to one object, at the same time deleting the overlap parts.
      • Group after Dissolving : Dissolve objects that have the same attribute fields and intersect or are tangent to each other to form a simple object. If the dissolving fields are the same after dissolving, group it to a complex object.
      • Dissolve Tolerance : If the distance between two or more nodes are in the tolerance, the nodes will be merged to one node. The default value is one millionth of the dataset border (the maximum tolerance is 100 times of the default tolerance), the unit is the original unit of the dataset.

    Note : For a text dataset, the dissolving mode only can be Union. Setting a tolerance is meaningless.

    • Filter : Only objects that meet a certain condition will be involved in the calculation.
    • Process objects which have no field values : checking the box means operating on the objects which have no dissolving filed values.
    • Result Data : Specify a datasource to save the result dataset.
    • Field : The fields that have the same value in the dataset. Dissolve or group the dataset value according to this field value.

    • Statistical Field : Select the statistic method and create new field save value, the statistic method can be Max, Min, Sum, Average, First Object and Last Object.

      • Max: The maximum value of the dissolve/group object, only support numeric and time fields.
      • Min: The minimum value of the dissolve/group object, only support numeric and time fields.
      • Sum: The sum value of the dissolve/group object, only support numeric fields.
      • Average: The average value of the dissolve/group object, only support numeric fields.
      • First Object: The field value of the object with the minimum SmID in the dissolve/group objects.
      • Last Object: The field value of the object with the maximum SmID in the dissolve/group objects.

    Note

    • When the values of the dissolve field are the same, if there are three or more line with end point coincide as one point, the system will not perform the dissolving operation.