三.空间数据的采集与产生.ppt

编辑图层中要素的属性 属性字段可以在创建图层是定义，也可以在ArcMap中添加 Fields are added; define 字段名称：field name 数据类型：data type 字段宽度：width 精度：decimal precision 打开图层（要素类）的属性表，添加新字段 添加属性字段 编辑要素属性信息 在属性字段添加后，就可以输入或修改要素的属性 编辑环境及工具 主要编辑环境－“编辑器”工具栏 “编辑器”工具栏 捕捉环境－Snapping 捕捉或悬挂操作: how features align during creation/editing 线段之间的连接 (在两条线段连接的地方加一个结点) completion of polygons avoid overshoots/undershoots avoid slivers or gaps 捕捉环境－Snapping 通过捕捉环境对话框设定在编辑时捕捉方式 Snapping options Interactive snapping options Snap to an existing vertex Snap to an existing line segment or polygon edge Snap to an intersection of two or more lines Snap to an existing line endpoint Snapping can be layer-to-layer_ 捕捉－线段 Undoing edits Edits can be undone in reverse order Edits can be undone up to the previous save (or creation) Once a dataset’s changes are saved, edits cannot be undone Saving edits Save EARLY and OFTEN You are prompted to save edits when: Dataset is closed for editing Another dataset is opened for editing Document is saved or closed ArcGIS is closed 点要素的编辑 在图层中新建、删除、移动一个点要素 线要素的编辑 悬挂功能 修改线段的形状（编辑顶点） 分割线要素、公共顶点的编辑 合并线要素 封闭线段 打断线要素 打断工具 封闭线段 多边形要素的编辑 多边形顶点编辑（改变形状） 分割多边形 公共边的编辑 要素合并（Union）：求并集，比如：由多个岛屿组成的行政区，飞地。 要素联合（Combine): 中心有岛屿的湖泊 要素相减（Subtract）：去除重叠部分（landuse) 要素相交（Intersection): 获取多个多边形的公共部分 Altering the shape of lines and polygons topological editing Altering the shape of lines and polygons non-topological editing Splitting (cutting) polygons Splitting features Geodatabase splitting policies Attributes are handled by policies Duplicate: values in new records are copied from the parent record Geometry property (e.g., area, perimeter, length) automatically handled Geometry ratio (e.g., population)_ Splitting features Attribute splitting (for geodatabase feature classes) is handled by policies image from ESRI Merging polygons select multiple polygons from the same layer original polygons are merged into a single new polygon Merging polygons Attributes are handled by rules in the same way as splitting image from