JPH07271846A - Method and device for optimum arrangement of node - Google Patents

Abstract

PURPOSE:To provide node optimum arrangement method and device capable of completely storing the relative relation of map coordinates within a fixed processing time without generating the coordinate overlap of nodes independently of uniformity in the distribution of node density and transforming the map coordinates into logical coordinates. CONSTITUTION:A network constitution retrieving processing part 105 retrieves a network constitution managing data base 106 in accordance with a user's request condition inputted from a retrieving condition input processing part 104 and inputs retrieved result displaying information 110 to be a subset of extracted network struction elements to a node optimum arrangement processing part 108 together with graphic display reference information 107. While storing geographic relative position relation of a real world, the processing part 108 transforms map coordinates into logical coordinates for an optional display space and a link optimum arrangement processing part 109 executes link arrangement processing between nodes and displays network constitution display information 111 on a graphic display part 103.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a network configuration display system for displaying a logical connection status between nodes which are network components in a communication network, a power system, a gas pipeline network, a water network, etc., The present invention relates to a node optimal arrangement method and apparatus for converting a map coordinate to a logical coordinate while preserving a relative positional relationship of map coordinates in the real world showing a connection state between nodes and without overlapping of the nodes.

[0002]

2. Description of the Related Art In this type of network configuration display system,
For example, a conventional communication network configuration display system for a communication network displays all the node elements that make up the communication network in proportion to the map elements, and the network configuration is achieved by a partial enlargement / reduction operation by a user's screen operation. Part of the element is highlighted.

On the other hand, a system is realized in which after extracting a subset of network components to be highlighted from the database, the nodes are optimally arranged on the logical coordinates of the display space based on the relative positional relationship of the map coordinates of the subset. ing. In such a system, map coordinates are converted to logical coordinates by calculating the logical coordinates by dividing the map coordinates by the ratio of the space between the map coordinates and the logical coordinates without checking for the presence of overlapping nodes. There is. For this reason, nodes in geographically dense node areas such as urban areas cause duplication of node coordinates on the logical coordinates.

Conventionally, this node duplication is a process of calculating a node density distribution on a sub-logical coordinate space obtained by dividing the logical coordinate space, and bringing the node density of the sub-logical coordinate space closer to the average density (density distribution uniformizing process). Alternatively, the nodes are interactively overlapped by automatic means such as moving a node in the direction in which the map coordinates of the duplicated nodes are different from each other (node adjacent coordinate movement processing), or by manual movement means by which the user directly specifies the movement destination. Has been resolved.

[0005]

In the above-described conventional density distribution equalizing process, depending on the balance of the density distribution of the nodes, a process of rearranging the entire space may be caused, resulting in a prediction of the processing time. However, it may be difficult and takes a lot of processing time. In addition, in the node adjacent coordinate movement processing in a very close range, it may not be possible to save some of the relative relations between the node coordinates, so it is necessary to always check for node duplication after the node placement processing. .

Therefore, in order to confirm the result of the coordinate conversion,
There is a problem that user's intervention is always required, and continuous automatic processing of node arrangement and link display processing cannot be performed.

Further, since the node placement processing is performed every time the network component subset is searched from the database, there is a problem that the same processing is repeated for the subset in which the nodes are not changed.

The present invention has been made in view of the above,
The purpose of this is that, regardless of the uniformity of the node density distribution, the coordinates of nodes are not overlapped, the relative relationship of map coordinates is completely saved within a certain processing time, and the map coordinates are set to logical coordinates. An object of the present invention is to provide a node optimal placement method and apparatus for converting to.

[0009]

In order to achieve the above object, a method for optimally allocating nodes according to the present invention is a method for extracting network components extracted from all network components stored in a network configuration management database in accordance with user requirements. This is a node optimal placement method that transforms map coordinates to logical coordinates in an arbitrary display space while preserving the geographical relative positional relationship of the real world for the nodes included in the subset. Enlarge to a sufficiently large coordinate space that will not be displayed redundantly, then find the reduction ratios of the X-axis and Y-axis of the map coordinates of the real world and the logical coordinates of the display space, and use a value smaller than the reduction ratio. By alternately and stepwise reducing the X-axis and Y-axis node intervals, checking the occurrence of node duplication in the reduction process to eliminate duplication, and repeating the conversion up to the target logical coordinate size. And summarized in that the optimal placement on the logical coordinate of the display space more nodes.

Further, in the above-described node optimal placement method, the above-mentioned method is used to continuously link the nodes optimally placed on the logical coordinates of the display space using the logical coordinates converted by the node placement processing. The gist is to perform the placement process.

Further, in the optimum node placement method of the present invention, the created node placement information is stored for each subset of network components, and a node addition / deletion and a change in map coordinate movement are performed each time a search is performed. The gist is to check the existence and use the accumulated node arrangement information when there is no change.

The node optimum placement device of the present invention is a real-world geographical relative node that is included in a subset of network components extracted from all network components stored in the network configuration management database according to user requirements. A node optimal placement device that converts map coordinates to logical coordinates in an arbitrary display space while preserving the positional relationship, and expands real world map coordinates into a sufficiently large coordinate space in which nodes are not displayed in duplicate. And a reduction ratio between the X-axis and the Y-axis of the map coordinates of the real world and the logical coordinates of the display space, and a value smaller than the reduction ratio is used to alternately and step the node intervals of the X-axis and the Y-axis. Reduction means for automatically reducing, duplicate elimination means for checking the occurrence of node duplication in the reduction process and eliminating duplication, and repeating the transformation up to the target logical coordinate size And summarized in that a means for optimal placement on the logical coordinate of the display space.

Further, the node optimal placement device of the present invention, in the above, continuously links between the nodes optimally placed on the logical coordinates of the display space by using the logical coordinates converted by the node placement processing. The gist is to have a means for performing the arrangement processing.

Further, the node optimum placement device of the present invention stores the created node placement information for each subset of network components in the above, and every time a search is performed, a node addition or deletion and a change in map coordinate movement are performed. The gist is to have means for checking the existence and use of the accumulated node arrangement information when there is no change.

The optimum node placement device of the present invention is a node for converting real-world map coordinates showing connection statuses between nodes into logical coordinates while preserving the relative positional relationship of the map coordinates without mutual duplication of the nodes. An optimal placement device, which checks the given map coordinate duplication and uses the specified source to completely eliminate the node coordinate duplication regardless of the uniformity of the node density distribution. Means for eliminating the duplication of nodes by enlarging the map coordinates, means for alternately reducing the node intervals of the enlarged map coordinates with respect to the X coordinate axis and the Y coordinate axis, and checking for duplication of the reduced nodes, A gist includes means for eliminating node duplication, means for checking whether the target logical coordinate space has been reached, and means for performing link placement processing after executing node placement processing. .

[0016]

According to the optimum node placement method of the present invention, the map coordinates of the real world are expanded to a sufficiently large coordinate space in which the nodes are not displayed in duplicate, and the map coordinates of the real world and the logical coordinates of the display space are X. The reduction ratio of the axis and the Y-axis is obtained, and the node interval of the X-axis and the Y-axis is reduced alternately and stepwise by using a value smaller than the reduction ratio, and the duplication of nodes in the reduction process is removed.
The nodes are optimally arranged on the logical coordinates of the display space by repeating the conversion up to the target logical coordinate size.

Further, according to the node optimal placement method of the present invention,
In the above, the link placement process is continuously performed between the nodes optimally placed on the logical coordinates of the display space using the logical coordinates converted by the node placement process.

Furthermore, in the node optimal placement method of the present invention,
In the above, the created node arrangement information is accumulated, and every time a search is performed, it is checked whether or not there is a change in addition or deletion of a node and movement of map coordinates. If there is no change, the accumulated node arrangement information is used.

In the node optimal arrangement device of the present invention, the map coordinates of the real world are expanded to a sufficiently large coordinate space in which the nodes are not overlapped and displayed, and the real world map coordinates and the logical coordinates of the display space are X. The reduction ratio of the axis and the Y-axis is obtained, the node interval of the X-axis and the Y-axis is reduced alternately and stepwise by using a value smaller than the reduction ratio, the duplication of nodes in the reduction process is removed, and the target logical coordinate The nodes are optimally arranged on the logical coordinates of the display space by repeating the conversion up to the size of.

Further, in the node optimal placement device of the present invention,
In the above, the link placement process is continuously performed between the nodes optimally placed on the logical coordinates of the display space using the logical coordinates converted by the node placement process.

Furthermore, in the node optimal placement device of the present invention,
In the above, the created node arrangement information is accumulated for each subset of network components, and there is a means for checking whether or not there is a change in the addition or deletion of nodes and movement of map coordinates each time a search is performed. Uses the accumulated node placement information.

In the node optimum placement device of the present invention, the overlap of the given map coordinates is checked, the overlap of the nodes is eliminated by enlarging the map coordinates, and the node intervals of the expanded map coordinates are compared with the X coordinate axis and the Y coordinate. Alternately reduce the coordinate axes, eliminate duplication of the reduced nodes, check whether the target logical coordinate space is reached, and perform the link placement process after executing the node placement process.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a network configuration display system to which a node optimal placement method according to an exemplary embodiment of the present invention is applied. The network configuration display system shown in the figure is applicable to a communication network, an electric power system, a gas pipeline network, a water supply network, and the like. In the present embodiment, a case where the network configuration display system is applied to a communication network will be described as an example.

The network configuration display system shown in FIG. 1 comprises a database search unit 101, a graphic information creation unit 102, and a graphic display unit 103. The database search unit 101 includes a search condition input processing unit 104 for inputting a search condition from a user, and the network configuration management database 10 according to the search condition input from the search condition input processing unit 104.
6 is composed of a network configuration search processing unit 105 for searching 6 and a network configuration management database 106. Further, the graphic information creation unit 102 receives the graphic display basic information 107 including the map coordinate information of the nodes in the real world and the search result display target information 110 from the database search unit 101, and the node optimal placement processing unit 108 and the link. It is composed of the optimum placement processing unit 109. The network configuration display information 111 from the graphic information creating unit 102 is input to the graphic display unit 103 and displayed on the graphic display unit 103. It is assumed that the graphic display unit 103 uses any existing tool capable of displaying a drawing by designating coordinates and an object.

FIG. 2 is a flow chart showing the main processing of the network configuration display system shown in FIG. The processing flow of the network configuration display system shown in the figure is the network configuration search processing 201 that is interactively activated by a user request, and is activated each time the network configuration search processing 201 is activated and a new display target is retrieved. Optimal node placement processing 202 and link optimal placement processing 2 for automatically displaying the new network configuration
It is composed of 03.

More specifically, in the processing of the network configuration display system shown in FIG. 2, first, it is awaited whether or not there is a new search request from the user (step 211). The data search condition is set by (step 213), and the network configuration management database 106 is searched based on this search condition (step 2).
15).

The display target information 11 of this search result
When 0 is input to the node optimum placement processing unit 108 together with the graphic display basic information 107, the node optimum placement processing unit 1
08 performs the node optimal placement process 202. In this process, as will be described later, first, the difference from the existing node arrangement is checked (step 221), then the X coordinate is converted at a constant ratio (step 222), and the Y coordinate is converted at a constant ratio (step 223). ). Then, it is checked whether or not the target size is converted by this conversion (step 224). If the target size is not converted, the process returns to step 222 and the target size is converted. The conversion process of steps 222 and 223 is repeated until, but when the target size is converted, the node arrangement result is accumulated (step 225).

Next, the link optimal placement processing unit 109 creates inter-node shortest route data based on the node placement result from the node optimal placement processing unit 108 (step 23).
1) Create line segment duplication avoidance connection point data (step 233). Then, the network configuration display information 111 thus created is displayed on the graphic display unit 103 (step 235).

FIG. 3 is a diagram showing an outline of the coordinate conversion processing for node arrangement. In the drawing, circles with diagonal lines indicate nodes, but the display target node groups 302 and 303 are selected from all the nodes in the map coordinate space 301, and the logical coordinate spaces 304, 305 and 306 of the display destination are selected. When set,
The map coordinates are converted into logical coordinates while preserving the relative positional relationship between the display target node groups, and the display space A30
7, B308, B309 are displayed. When the coordinates are expanded as in the logical coordinate space 306, the coordinates of the nodes do not overlap with each other and can be easily obtained by multiplying the map coordinates by the expansion ratio of the map coordinates and the logical coordinates. The node optimal placement method of the present invention is particularly related to the case of coordinate reduction such as the logical coordinate spaces 304 and 305 in which node coordinate duplication may occur in coordinate transformation.

FIG. 4 is a flow chart showing the node placement information creation process in the node optimal placement method of this embodiment. The node placement information creation process shown in the figure includes a difference check process 401 with the already created node placement, a map coordinate deduplication process 402, a coordinate reduction conversion process 403, a coordinate enlargement conversion process 404, a node placement result saving process 405, and an existing process. It has a quoting process 406 of the node placement result.

More specifically, in the node arrangement information creating process shown in FIG. 4, first, the target subset number of the database (DB) search is acquired (step 411), and then the node arrangement result of the same subset number is acquired (step 412), adding nodes in the subset from both,
A difference such as deletion is detected (step 413), and it is checked whether or not a node is added or deleted (step 41).
4). As a result, if no node is added or deleted,
Quoting the existing node placement result (step 461),
Although the processing is terminated, if there is addition or deletion, it is first checked whether the actual coordinates are larger than the logical coordinates (step 420).

If the real coordinates are not greater than the logical coordinates,
That is, when the logical coordinate is larger than the actual coordinate, the coordinate enlargement conversion process is performed (step 441), the node arrangement result is saved (step 451) and the process ends, but the actual coordinate is larger than the logical coordinate. If it is larger, map coordinate deduplication processing is performed for all nodes (step 42).
1). Note that this map coordinate deduplication processing is shown in FIG.
Will be described in detail.

When the map coordinate duplication elimination processing is completed in step 421, the coordinate reduction conversion processing is performed, so that the X coordinate reduction calculation is first performed (step 431) and then the Y coordinate reduction calculation is performed (step 432). Then, it is checked whether the size has been converted to the target size (step 43).
3) If the size has not been converted to the target size, the process returns to step 431 and the same process is repeated. However, if the size has been converted to the target size, the coordinate enlargement conversion process is performed (step 441). The placement result is saved (step 451) and the process ends.

Next, details of the map coordinate duplication elimination processing 402 in the node arrangement information creation processing shown in FIG. 4 described above will be described with reference to the flowchart shown in FIG. The map coordinate de-duplication processing shown in FIG. 5 includes duplicate node detection processing 501, processing 502 for securing a space at the destination of the duplicate node, and processing 5 for setting the destination coordinate of the duplicate node.
Has 03.

In the map coordinate duplication elimination processing shown in FIG. 5, node coordinate information is sorted using the X coordinate as the primary key and the Y coordinate as the secondary key (step 511). Then, the loop processing is set to repeat the subsequent processing, that is, the processing from steps 513 to 533 to all the processing nodes (step 512). Then, the coordinates of the processing node currently being processed are set as the processing coordinates (step 513), and the processing node is registered in the overlapping coordinate node table (step 514).

Further, a loop process for repeating the processes of the following steps 516 to 518 is set (step 5
15) The coordinates of the comparison node currently being processed are set to the comparison node coordinates (step 516), and it is checked whether the processing coordinates are equal to the comparison coordinates (step 517). If they are not equal, the process returns to step 515 and the same processing is repeated, but if they are equal, the comparison node is registered in the duplicate coordinate node table (step 518).

Next, it is checked whether the number of registered duplicate nodes is larger than 1 (step 521). If it is not larger than 1, the process is terminated as it is, but if it is larger than 1, the process proceeds to step 522, and a loop process is set to repeat the process of step 523 with N being a variable from 3 to the multiple number. Then, in step 523, the number of additional XY = duplication number / N is calculated, and it is checked whether the remainder is 0 or not. If the remainder is not 0, the process returns to step 522 and repeats the same processing, but if the remainder is 0, the process proceeds to step 524.

In step 524, the processes of the following steps 525 and 526 are repeated for all the comparison nodes. In step 525, the processing node coordinate is subtracted from the comparison node coordinate to calculate the coordinate difference, and the coordinate difference is 0.
It is checked whether or not it is larger (step 526).
If the coordinate difference is not greater than 0, the process returns to step 524 and the same processing is repeated. If the coordinate difference is greater than 0, it is checked whether the additional XY number is greater than or equal to the coordinate difference (step). 527). If the additional XY number is smaller than the coordinate difference, the process proceeds to step 531. If the additional XY number is larger than or equal to the coordinate difference, the coordinate of the comparison node is incremented by 1 (step 528).
Proceed to step 531.

In step 531, the duplicate node is extracted from the duplicate coordinate node table, the destination coordinate is set (step 532), the duplicate coordinate node table is reset (step 533), and the process is terminated.

Next, details of the X-coordinate reduction calculation process of the coordinate reduction conversion process 403 in the node arrangement information creation process shown in FIG. 4 will be described with reference to the flowchart shown in FIG. Coordinate reduction conversion processing 403 shown in FIG.
The X-coordinate reduction calculation processing of (1) has a new coordinate calculation processing loop 601 for the corresponding X-axis and a new coordinate setting processing loop 602 for the corresponding X-axis in a large loop that simultaneously processes the same X-coordinate node from small coordinates. A new coordinate calculation processing loop 601 is a new coordinate calculation processing 603 for the corresponding X axis, an interlace inspection and update processing 604 for the new X coordinate on the same Y axis node,
It has a maximum X coordinate check and update process 605 within the process range.

Further, the new coordinate calculation processing 603 derives the new coordinate by rounding down (X coordinate / 2) after the decimal point.
The interlaced X coordinate inspection and update processing 604 checks whether there is a node on the same X axis between the pre-conversion coordinate and the post-conversion coordinate, and if there is, the post-conversion coordinate is set to this coordinate + 1. Change to. Maximum X coordinate update processing 605
Updates the maximum X coordinate if the converted coordinate is larger than the maximum X coordinate within the processing range. The calculation of the new Y-coordinate can be performed by the same process by simply reading the X-axis as the Y-axis.

FIG. 7 is a flow chart showing the details of the new X coordinate interlace inspection and update processing 604 in the X coordinate reduction calculation processing of the coordinate reduction conversion processing shown in FIG. In the interlace checking and updating process of the new X coordinate shown in FIG. 7, first the parameters are initialized, then the X coordinate and the Y coordinate are acquired for all of the processing nodes, and whether or not the acquired Y coordinate is equal to the comparison Y coordinate. Check, X
Checks whether the coordinates are equal to the old X coordinates, checks whether the X coordinates are equal to the comparison X coordinates, and if they are equal, the value obtained by adding 1 to the X coordinate is set as the return value, and this return value is set. It is inherited as a parameter.

FIG. 8 is a flow chart showing the details of the maximum X coordinate inspection and update processing 605 within the processing range of the X coordinate reduction calculation processing of the coordinate reduction conversion processing shown in FIG. In the maximum X coordinate inspection and update processing within the processing range shown in FIG. 8, the parameters are first initialized, then the X coordinate of the processing node is acquired, and it is checked whether the X coordinate is larger than the comparison X coordinate. It is checked whether or not the coordinate is larger than the return value, and if it is larger, the X coordinate is used as the return value, and this return value is taken over as a parameter.

FIGS. 9 and 10 show how the node coordinates change stepwise when the above-described processing is performed, from the conversion start of the X coordinate to the conversion end and the conversion start of the Y coordinate to the conversion end. FIG.
9 and 10, the white circles represent coordinate-unconverted nodes, the circles shaded in one direction represent the X coordinate transformed nodes, and the circles shaded in both directions represent the X and Y coordinate transformed nodes. Is shown. Further, in the conversion of the X coordinate shown in FIG. 9, the X coordinate is reduced from the smaller X coordinate and the X coordinate is updated, and in the conversion of the Y coordinate shown in FIG. The coordinates are reduced and the XY coordinate conversion process is performed.

[0045]

As described above, according to the present invention,
Enlarge the map coordinates of the real world into a coordinate space that is large enough so that duplicate nodes are not displayed, find the reduction ratio of the X and Y axes of the map coordinates of the real world and the logical coordinates of the display space, and reduce the size. By using a value smaller than the ratio, the node spacings of the X-axis and the Y-axis are reduced alternately and step by step, the duplication of the nodes in the reduction process is removed, and the conversion is repeated up to the target logical coordinate size to display the nodes. Since it is optimally placed on the logical coordinates of nodes, the processing time is constant regardless of the uniformity of the node density distribution, and there is no duplication of nodes. Therefore, user intervention can be avoided, and nodes can be linked continuously from node placement. Even the display can be performed, and the interactive operation can be smoothly performed.

Further, according to the present invention, the created node arrangement information is accumulated, and every time a search is performed, it is checked whether or not there is a change in addition or deletion of a node and movement of map coordinates, and if there is no change, it is accumulated. Since the node placement information is used,
It is possible to perform the node arrangement processing in a short time without repeating the node arrangement processing repeatedly as in the conventional case.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a network configuration display system to which a node optimal placement method according to an exemplary embodiment of the present invention is applied.

FIG. 2 is a flowchart showing main processing of the network configuration display system shown in FIG.

FIG. 3 is a diagram showing an outline of coordinate conversion processing for node arrangement.

FIG. 4 is a flowchart showing a node arrangement information creating process in the node optimum arrangement method of the embodiment shown in FIG.

5 is a flowchart showing details of map coordinate duplication elimination processing in the node arrangement information creation processing shown in FIG.

6 is a flowchart showing details of an X coordinate reduction calculation process of a coordinate reduction conversion process in the node arrangement information creation process shown in FIG.

7 is a flowchart showing the details of a new X coordinate interlace inspection and update process in the X coordinate reduction calculation process of the coordinate reduction conversion process shown in FIG.

8 is a flowchart showing details of maximum X-coordinate inspection and update processing within a processing range of the X-coordinate reduction calculation processing of the coordinate reduction conversion processing shown in FIG.

FIG. 9 is a diagram showing a state in which the node coordinates change stepwise when the node optimum placement processing is performed in the above-described embodiment, from the conversion start of the X coordinate to the conversion end.

FIG. 10 is a diagram showing a state in which the node coordinates change stepwise in the case of performing the node optimal placement process in the above-described embodiment, from the conversion start of the Y coordinate to the conversion end.

[Explanation of symbols]

 101 Database Search Unit 102 Graphic Information Creation Unit 103 Graphic Display Unit 105 Network Configuration Search Processing Unit 106 Network Configuration Management Database 108 Node Optimal Placement Processing Unit 109 Link Optimal Placement Processing Unit

Claims (7)

[Claims] 1. A map of nodes included in a subset of network components extracted from all network components stored in a network configuration management database in accordance with user requirements while preserving the real-world geographical relative positional relationship. It is a node optimal placement method that transforms coordinates to logical coordinates in an arbitrary display space.First, map coordinates in the real world are expanded to a sufficiently large coordinate space in which nodes are not displayed in duplicate, and then the actual coordinates are expanded. The reduction ratios of the X-axis and the Y-axis of the world map coordinates and the logical coordinates of the display space are obtained, and the node intervals of the X-axis and the Y-axis are reduced alternately and stepwise by using a value smaller than the reduction ratio. A node characterized by optimally arranging nodes on the logical coordinates of the display space by checking the occurrence of node duplication in the process, eliminating the duplication, and repeating the conversion up to the target logical coordinate size. Optimal placement method. 2. The link arranging process is continuously performed between the nodes optimally arranged on the logical coordinates of the display space by using the logical coordinates converted by the node arranging process. Optimal node placement method described. 3. The created node arrangement information is accumulated for each subset of network components, and every time a search is performed, the presence or absence of changes in the addition or deletion of nodes and the movement of map coordinates is checked, and if there is no change, it is accumulated. The optimum node placement method according to claim 1, wherein the selected node placement information is used. 4. A map of nodes included in a subset of network components extracted from all network components stored in a network configuration management database in accordance with user requirements while preserving the real world relative geographical position. A node optimum placement device for converting coordinates to logical coordinates in an arbitrary display space, and expanding means for expanding map coordinates of the real world into a sufficiently large coordinate space in which nodes are not displayed in duplicate. X-axis and Y of map coordinates and logical coordinates of display space
The reduction ratio of the axis is calculated, and a value smaller than the reduction ratio is used to obtain X
Reducing means for alternately and stepwise reducing the node intervals of the Y-axis and the Y-axis, duplication removing means for checking occurrence of node duplication in the reduction process and eliminating duplication, and repeating conversion up to the target logical coordinate size. And a means for optimally arranging the nodes on the logical coordinates of the display space. 5. A means for continuously performing link arrangement processing between the nodes optimally arranged on the logical coordinates of the display space using the logical coordinates converted by the node arrangement processing. The node optimal placement device according to claim 4. 6. A means for accumulating the created node arrangement information for each subset of network constituent elements, checking the presence or absence of changes in the addition and deletion of nodes and movement of map coordinates each time a search is performed, and there is no change. The node optimal placement device according to claim 4, wherein the node placement information accumulated is used in such a case. 7. A node optimum placement device for converting real-world map coordinates indicating a connection state between nodes into logical coordinates while preserving the relative positional relationship of the map coordinates without overlapping of the nodes, Regardless of the uniformity of the node density distribution,
To completely eliminate node coordinate duplication, the means to eliminate node duplication by checking the given map coordinate duplication and enlarging the map coordinate using the specified source is expanded. The means for alternately reducing the node intervals of the map coordinates with respect to the X coordinate axis and the Y coordinate axis, the means for checking the overlap of the reduced nodes and eliminating the overlap of the nodes, and reaching the target logical coordinate space An optimum node placement device having means for checking whether or not the link placement processing is performed after execution of the node placement processing.