For creating a new map it is necessary to select Map components type in any navigation window in hierarchical pane (it is also possible to select any existing map) and execute the menu command Edit+Add. A dialog box “Adding map” will be opened, it is shown at figure 9-8. In this box it is required to specify a set of parameters of the map that is being created.
Figure 9-8. Dialog box “Adding map”
String parameter Map name. For a map name an arbitrary string of symbols may be chosen. Map name should be unique within the range of the given GDB.
Three numeric parameters Base Point X, Y and Range. These parameters determine the square which is called map domain. Base point is the bottom-left point of the square, and the range is the square's side. Base point coordinates and the range are determined for the whole map, they are the same for all its layers.
Specifying the map domain does not prohibit to place features outside this area. However, the process of selecting such features and displaying them will be much slower.
Numerical parameter Partition. This parameter is connected with map internal representation in computer's memory. At first you can agree with the value offered by the system by default. Maximal parameter value is 255.
Later, when selecting the value of the parameter Partition it is recommended to stick to the following rules:
One should approximately evaluate which part of the whole map a typical segment with which the user will be working as a rule will occupy. Let's suppose that the line size of this segment makes about 1/10th from the square side of the map domain. It is recommended to take partition twice as detailed, that is, 20.
If after clicking the mouse button on one of the features of the displayed map too much time passes (several seconds) before this feature is selected (marked by color), then it is necessary to increase partition by 1.5 or 2 times. If the feature is selected practically momentarily you can try to decrease partition, it may help to reduce the time for map display.
All parameter values can be changed at any time, however this may require considerable time.
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