Position control device, method, and program

Abstract

A position control device according to one embodiment of the present invention includes: a setting unit that receives an input of information related to a plurality of nodes that can be displayed on a screen and at least one edge that connects two nodes among the plurality of nodes, and sets a node resulting from shifting a node belonging to a first layer among the plurality of nodes indicated by the input information so as to approach a node belonging to a second layer different from the first layer; a calculation unit that calculates an attractive force that an edge connecting the node belonging to the second layer and the node set by the setting unit exerts on the node belonging to the second layer; and a control unit that controls display positions of the plurality of nodes on the screen on the basis of the attractive force calculated by the calculation unit.

Description

Position control device, method and program

[0001] FIELD Embodiments of the present invention relate to a position control device, a method, and a program.

[0002] In order to efficiently maintain and operate a large-scale multi-layer network where complex failure cases occur, it is necessary for a network maintenance manager (hereinafter referred to as a "maintenance technician") to display information spanning various layers of the target network, such as the physical layer, transmission layer, or IP (Internet Protocol) layer, such as resources such as devices, or the relationships between resources, in an easy-to-read manner on a screen according to the purpose. In particular, in a complex network or a network with a relatively large number of nodes, it is a challenge to identify how the nodes should be arranged on the screen in order to display the information in an easy-to-read manner.

[0003] There are various methods for automatically arranging each node so that the network configuration, for example, resources such as devices and the relationships between resources, can be displayed appropriately on the screen, such as the methods shown in (1) and (2) below.

[0004] (1) Node placement technology based on a dynamic model The dynamic model method uses the network topology, where the connections between each node that makes up the network are based on a repulsive force between nodes (such as the Coulomb repulsive force that acts between molecules), and an attractive force that acts like a spring is applied to the edges between connected nodes, and the placement of each node that minimizes energy is calculated using the sum of these attractive and repulsive forces. When the attractive and repulsive forces between each node are balanced, a placement that is easy to see and has a good sense of distance between each node is obtained.

[0005] By appropriately applying the dynamic model, it is relatively common to obtain an arrangement in which nodes and edges do not overlap properly, and nodes that have a connection relationship with each other are arranged close to each other, resulting in an arrangement that is easy to view.

[0006] However, such a dynamic model approach determines placement based solely on information about the connection relationships between nodes, and therefore does not generally take into account information other than the connection relationships, such as hierarchical or layer structures.

[0007] (2) Hierarchical Network Node Arrangement Although technologies for realizing node arrangement based on the hierarchy of a network have been proposed and implemented, many of these technologies are premised on a directed acyclic graph (DAG), or are arranged under constraints such as simply arranging nodes of the same hierarchy in a line across the screen or on a specific plane (see, for example, Non-Patent Documents 2 or 3).

[0008] There is also a technique for introducing virtual nodes that have an attractive force only on nodes in a specific layer, and adjusting the placement for each layer (see, for example, Patent Document 1).

[0009] International Publication No. 2022 / 145055

[0010] FRUCHTERMAN, Thomas MJ; REINGOLD, Edward M. Graph drawing by force-directed placement, Software: Practice and experience, 1991, 21.11: 1129-1164.wikipedia “Layered_graph_drawing”, https: / / en.wikipedia.org / wiki / Layered_graph_drawingMcgee, Fintan & Ghoniem, Mohammad & Melangon, Guy & Pinaud, B.. (2019). The State of the Art in Multi‐Layer Network Visualization. Computer Graphics Forum. 38. 10.1111 / cgf.13610. https: / / onlinelibrary.wiley.com / doi / full / 10.1111 / cgf.13610

[0011] The characteristics of a multi-layer network can be roughly divided into the following two relationships (1) and (2): (1) Connection Relationships Between Resources Connection relationships between resources include physical connections between ports or connectivity between logical resources.

[0012] (2) Resource relationships between layers when corresponding resources for the same entity are represented in each of several layers. This relationship is, for example, the relationship between a logical port and the physical port that is its entity, or the components that make up a resource.

[0013] This relationship is, for example, the case where a path in a certain layer is formed by connecting several paths in a lower layer, such as a line that spans a higher layer and a lower layer, or the relationship between TPEs that belong to different layers in the NOIM model, or the relationship between an FRE (NC) and its constituent FREs (LC, XC).

[0014] When manually adjusting the placement of nodes, especially the latter relationship, corresponding nodes are often placed by shifting them by a certain amount in the direction of the upper or lower layer, etc. This is because the relationship between layers can be considered a kind of identification, and so the placement is like a closed placement on each layer being projected onto another layer, and the placement is such that nodes that have relationships between layers correspond to each other, which is thought to make it easier to grasp the relationship between nodes between layers.

[0015] However, there are the following problems (3) and (4): (3) Existing methods alone cannot automatically perform the above-mentioned placement. However, it is possible if the placement is confined to a single layer. (4) Manually adjusting the node positions is a very tedious task.

[0016] An example of manually adjusting the placement is described below. For example, the placement of nodes on each layer is grouped together within a certain range for each layer. In the closed range of each layer, edges are minimized from crossing each other, an appropriate distance is maintained between nodes, and nodes with a connection relationship are placed close to each other. This placement is similar to the placement of mechanical models in existing methods. Corresponding nodes are placed as if they were projected according to the relationship between the upper and lower hierarchies of each layer. In other words, groups of nodes corresponding to the same node are grouped together and placed close to each other.

[0017] The present invention has been made in light of the above circumstances, and its purpose is to provide a position control device, method, and program that can appropriately position nodes by taking into account the characteristics of the nodes.

[0018] A position control device according to one aspect of the present invention includes a setting unit that inputs information relating to a plurality of nodes that can be displayed on a screen and at least one edge connecting two of the plurality of nodes, and sets a node by shifting a node belonging to a first layer among the plurality of nodes indicated by the input information so that the node is closer to a node belonging to a second layer different from the first layer; a calculation unit that calculates the gravitational force that the edge connecting the node belonging to the second layer and the node set by the setting unit exerts on the node belonging to the second layer; and a control unit that controls the display position of the plurality of nodes on the screen based on the gravitational force calculated by the calculation unit.

[0019] A position control method according to one aspect of the present invention is a method performed by a position control device, and includes the steps of: inputting, by a setting unit of the position control device, information regarding a plurality of nodes that can be displayed on a screen and at least one edge connecting two of the plurality of nodes; setting a node by shifting a node belonging to a first layer among the plurality of nodes indicated by the input information so that the node is closer to a node belonging to a second layer different from the first layer; calculating, by a calculation unit of the position control device, an attractive force exerted on the node belonging to the second layer by the edge connecting the node belonging to the second layer and the node set by the setting unit; and controlling, by a control unit of the position control device, the display position of the plurality of nodes on the screen based on the attractive force calculated by the calculation unit.

[0020] According to the present invention, the characteristics of the nodes are taken into consideration to appropriately arrange the nodes.

[0021] FIG. 1 is a block diagram showing an example application of a network configuration diagram generating device according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of the process and result of node placement by a network configuration diagram generating device according to an embodiment of the present invention. FIG. 3 is a flowchart showing an example of processing operations by a network configuration diagram generating device according to an embodiment of the present invention. FIG. 4 is a diagram showing an example of the placement of nodes to be processed by a network configuration diagram generating device according to an embodiment of the present invention. FIG. 5 is a diagram showing an example of the placement result of nodes by a network configuration diagram generating device according to an embodiment of the present invention. FIG. 6 is a diagram showing an example of allocation of processing by layer by a network configuration diagram generating device according to an embodiment of the present invention. FIG. 7 is a diagram showing an example of the placement result of nodes by a network configuration diagram generating device according to an embodiment of the present invention when some repulsive forces are not taken into account. FIG. 8 is a block diagram showing an example of the hardware configuration of a network configuration diagram generating device according to an embodiment of the present invention.

[0022] An embodiment of the present invention will now be described. Fig. 1 is a diagram showing an application example of a network configuration diagram generating device according to an embodiment of the present invention. As shown in Fig. 1, the network configuration diagram generating device 100 according to an embodiment of the present invention includes a network configuration information input unit 11, a network configuration information storage unit 12, a placement information determination unit 13, a placement information storage unit 14, and a placement information output unit 15.

[0023] The network configuration information input unit 11 inputs network configuration information from outside. This network configuration information includes information on nodes, information on edges that are pairs of nodes, and information on the layer to which the nodes belong. The information input to the network configuration information input unit 11 is stored in the network configuration information storage unit 12. The other units of the network diagram generating device 100 will be described later.

[0024] In this embodiment, based on an existing automatic placement method for dynamic models that calculates the repulsive force between nodes and the attractive force of edges corresponding to the connection between two nodes and then places each node, the method separately calculates the attractive force exerted on a node by edges corresponding to the connection between nodes closed within the same layer and the attractive force exerted on a node by edges corresponding to the connection between nodes across different layers. Specifically, the existing method is applied as is to calculate the attractive force exerted by edges within the same layer, and the attractive force exerted by edges across different layers is calculated after shifting the position of the node by a certain amount for each layer.

[0025] In this embodiment, while arranging nodes within each layer in the same manner as in existing methods, it is possible to automatically arrange nodes in an easy-to-see manner, such that corresponding nodes are projected onto the upper and lower layers according to the hierarchical relationship of the nodes across the layers.

[0026] In this embodiment, an arrangement having the following characteristics (1) to (3), as shown in the "Example of Manually Adjusted Arrangement" above, is automatically performed. (1) For example, the arrangement of nodes on each layer is consolidated within a certain range for each layer. (2) In the closed range of each layer, edges are minimized from crossing, a reasonable distance is maintained between nodes, and nodes with a connection relationship are placed close to each other. This arrangement is similar to the arrangement of mechanical models in existing methods. (3) Corresponding nodes are placed as if projected according to the relationship between the upper and lower hierarchical levels of each layer. In other words, groups of nodes corresponding to the same node are placed close to each other. Because attractive forces are generated after shifting between different layers, groups of nodes on each layer are placed close to each other with a certain amount of spacing between them. Because edges between layers do not affect the closed range of each layer, an arrangement based on an existing mechanical model is performed.

[0027] 2 is a diagram showing an example of the process and result of node placement by a network topology diagram generation device according to an embodiment of the present invention. In the example shown in FIG. 2(a), as the initial placement of each node, "node A" and "node B" are placed in a higher hierarchical layer and have a connection relationship with each other, "node A" has a connection relationship across layers with a first node placed in a lower hierarchical layer, and "node B" has a connection relationship across layers with a second node placed in the lower hierarchical layer.

[0028] In this lower layer, the first node and the second node have a connection relationship with each other, and the three nodes including the first node and the second node have a triangular connection relationship overall.

[0029] In the example shown in FIG. 2(b), the network configuration diagram generating device 100 places a virtual node in the upper layer that corresponds to a node obtained by shifting the placement of three nodes in the lower layer by a certain amount toward the upper layer.

[0030] The network diagram generating device 100 calculates the attractive force exerted by the edge, which is the connection relationship between the shifted node and a node in a higher hierarchy, on the node concerned, based on the position of the shifted virtual node. In the example shown in Figure 2(c), in a pair of a virtual first node obtained by shifting a first node having a connection relationship with "Node A" in the higher hierarchy to a higher hierarchy, the attractive force exerted by the edge between "Node A" and the virtual first node on "Node A," in this case, an attractive force that attracts "Node A" to the virtual first node, occurs. Also, in the example shown in Figure 2(c), in a pair of a virtual second node obtained by shifting a second node having a connection relationship with "Node B" in the higher hierarchy to a higher hierarchy, the attractive force exerted by the edge between "Node B" and the virtual second node on "Node B," in other words, an attractive force that attracts "Node B" to the virtual second node, occurs.

[0031] In the example shown in (d) of Figure 2, the gravitational force generated as described above causes the placement of "Node A" in the upper hierarchy to approach the placement of the virtual first node shifted to the upper hierarchy, and the gravitational force generated as described above causes the placement of "Node B" in the upper hierarchy to approach the placement of the virtual second node shifted to the upper hierarchy.

[0032] As a result, according to the hierarchical relationship of each layer, the arrangement of corresponding nodes, i.e., "node A" in the upper layer and the actual arrangement of the first node before shifting, approaches the arrangement projected between the upper layer and the lower layer.

[0033] In the example shown in (e) of Figure 2, the processing result of the placement of each node shows the placement of "node A" and "node B" in the upper hierarchy, whose placement has been changed from the initial placement, and three nodes in the lower hierarchy, after the shifted virtual nodes have been removed from each node shown in (d) of Figure 2.

[0034] 3 is a flowchart showing an example of processing operations performed by a network configuration diagram generating device according to one embodiment of the present invention. The placement information determination unit 13 acquires information on each node and each edge from the network configuration information storage unit 12. The placement information determination unit 13 determines the initial placement of each node. The placement information determination unit 13 classifies each edge into an edge within a layer and an edge between layers. The placement information determination unit 13 acquires the amount of shift for each layer from the network configuration information storage unit 12 (S11).

[0035] If the placement information determination unit 13 has not repeated the subsequent steps S13 to S17 a specified number of times, in this case the number of times required to take into account all repulsive forces between nodes and attractive forces exerted by edges in the vector calculation for each node (No in S12), it calculates vectors representing repulsive forces between nodes for all nodes indicated by the information stored in the network configuration information storage unit 12 (S13).

[0036] Next, the placement information determination unit 13 calculates a vector representing the gravitational force exerted by the edges in the layer indicated by the information stored in the network configuration information storage unit 12 on the nodes indicated by the information, and adds this vector to the vector for each node calculated in S13 (S14).

[0037] Next, the placement information determination unit 13 calculates a vector representing the gravitational force exerted by the edge between layers on the node indicated by the information stored in the network configuration information storage unit 12, based on the position of each node shifted according to the shift amount of the layer to which the node belongs, and adds this vector to the vector for each node calculated in S14 (S15). However, the shifted position is only used in the calculation of the vector, and is not reflected in the position of the node that is the processing result.

[0038] The placement information determination unit 13 determines a new position of each node by reflecting the vector representing the attractive or repulsive force calculated for each node up to S15 on the position of each node (S16).

[0039] After S16 is completed, if the processing of S16 has been repeated the specified number of times (Yes in S12), the placement information determination unit 13 stores the position information (placement information) indicating the position of each determined node in the placement information storage unit 14.

[0040] Based on the network configuration information stored in the network configuration information storage unit 12 and the position information stored in the configuration information storage unit 14, the placement information output unit 15 presents information indicating each node placed at a new position on the screen and the edges connecting each node to the user by displaying it on a display device or outputting it to another functional unit, thereby completing the series of processes. The basic flow of the part surrounded by line F1 in FIG. 3 and detailed processing of each step may be performed using known techniques, for example, as described in Non-Patent Document 1. However, in this embodiment, the difference from the algorithm described in Non-Patent Document 1 is that edges are divided into two types: those closed within a layer and those spanning multiple layers. Those closed within a layer are processed according to existing methods, while those spanning multiple layers are processed based on the position to which the node is shifted as described above. The vector calculations in S14 and S15 may be performed using known techniques, for example, as described in Non-Patent Document 1.

[0041] FIG. 4 is a diagram showing an example of the placement of each node to be processed by a network configuration diagram generating device according to an embodiment of the present invention. FIG. 5 is a diagram showing an example of the placement result of each node by a network configuration diagram generating device according to an embodiment of the present invention. When node placement processing is performed by the network configuration diagram generating device 100 according to this embodiment for the multi-layer network configuration shown in FIG. 4, the two-dimensional placement result of each node is shown in FIG. 5(a), and the three-dimensional placement result of each node is shown in FIG. 5(b). This node placement processing may be performed in conjunction with the method disclosed in Patent Document 1, for example, which makes it easier to approach the ideal node placement.

[0042] In this example, the processing of S15 is performed based on the positions obtained by shifting the node position in the top service layer by 200, the node position in the next lower VLAN layer by 600, the node position in the next lower transmission layer by 1000, the next lower LD (Logical Device) layer by 1400, and the bottom physical layer by 1800 in the vertical axis direction in Figure 5(a) or the y axis direction in Figure 5(b).

[0043] In both the two-dimensional and three-dimensional arrangement of nodes, the processing method described in Non-Patent Document 1 can be used. When the nodes are arranged three-dimensionally, they are ultimately projected onto a two-dimensional plane.

[0044] Other application examples will be described. (Processing Allocation for Each Layer) FIG. 6 is a diagram showing an example of processing allocation for each layer by a network configuration diagram generation device according to one embodiment of the present invention. By allocating different processing methods for each layer during the vector calculation process, it is possible to enable placement based on various policies. For example, for the physical layer, which is the lowest layer shown in FIG. 6, node placement is performed and fixed based on the latitude and longitude of the building in which the actual equipment is housed, and node placement in this embodiment is performed only for layers above the physical layer. In other words, all nodes and edges are used in the vector calculation, but the vector calculation results are applied only to nodes in layers above the physical layer, so that physical equipment is displayed at a position based on its real-world placement (reference symbol a in FIG. 6), and logical resources are placed based on their relationship with each other.

[0045] Also, using a similar concept, when you want to determine the placement of the upper layer based on the placement of the devices in the lower layer, that is, when you want to determine the placement of the devices in the lower layer without affecting the placement of the upper layer, you can achieve placement according to the relevant policy by making the gravitational force that the edges that cross layers exert on the nodes one-way.

[0046] 7 shows an example of the placement results of each node when some repulsive forces are not taken into account by a network topology diagram generation device according to an embodiment of the present invention. For example, when there is an edge that straddles an area (symbol a in FIG. 7 ) where multiple nodes are densely packed, and there is a node (node ​​"A" in FIG. 7 ) at one end of this edge and a node (node ​​"B" in FIG. 7 ) at the other end of this edge ((a) in FIG. 7 ), a relatively strong repulsive force is generated from the nodes in this area. Therefore, the repulsive force (symbol c in FIG. 7 ) due to the densely packed nodes exceeds the attractive force (symbol b in FIG. 7 ) due to this edge, and the placement of the nodes at both ends of the edge may become unnatural, i.e., the placement may fall into a locally optimal solution.

[0047] During repeated vector calculation processing, the repulsive forces due to the densely packed nodes described above can be ignored, i.e., vector calculation is performed using only the attractive forces of the edges (FIG. 7(b)). Alternatively, by changing the balance between the strength of the repulsive and attractive forces, i.e., by relatively weakening the repulsive forces, the node at the other end of the edge can jump over the densely packed nodes described above and approach the node at one end of the edge, which may result in a more natural arrangement (FIG. 7(c)). Other types of forces can also be applied. Various methods can be considered for the frequency, etc., such as applying it probabilistically or determining it by phase. For example, by making the attractive forces relatively strong in the initial phase, it is easier to obtain a cohesive arrangement for each connected component.

[0048] 8 is a block diagram showing an example of the hardware configuration of a network configuration diagram generation device according to an embodiment of the present invention. In the example shown in FIG. 8, the network configuration diagram generation device 100 according to the embodiment is configured, for example, by a server computer or a personal computer, and has a hardware processor 111A such as a CPU (Central Processing Unit). A program memory 111B, a data memory 112, an input / output interface 113, and a communication interface 114 are connected to this hardware processor 111A via a bus 115.

[0049] The communication interface 114 includes, for example, one or more wireless communication interface units, and enables transmission and reception of information to and from a communication network. As the wireless interface, for example, an interface that adopts a low-power wireless data communication standard such as a wireless LAN (Local Area Network) is used.

[0050] An input device 500 and an output device 600, which are attached to the network configuration diagram generating device 100 and used by a user or the like, are connected to the input / output interface 113. The input / output interface 113 can take in operation data input by a user or the like through the input device 500, such as a keyboard, touch panel, or touchpad, and can output and display output data to an output device 600, which includes a display device using a liquid crystal or organic electroluminescence (EL) display. The input device 500 and the output device 600 may be devices built into the network configuration diagram generating device 100, or may be input devices and output devices of other information terminals that can communicate with the network configuration diagram generating device 100 via a network.

[0051] The program memory 111B is a non-transitory tangible storage medium that is a combination of a non-volatile memory that can be written to and read from at any time, such as a hard disk drive (HDD) or a solid state drive (SSD), and a non-volatile memory such as a read only memory (ROM), and can store programs necessary to execute various control processes, etc., according to one embodiment.

[0052] The data memory 112 is a tangible storage medium that is, for example, a combination of the above-mentioned nonvolatile memory and a volatile memory such as RAM (Random Access Memory), and can be used to store various data or information acquired and created during various processes.

[0053] The network block diagram generating device 100 according to one embodiment of the present invention can be configured as an information processing device having the units shown in FIG. 1 as software-based processing function units.

[0054] The information storage unit used as a work memory or the like by each unit of the network configuration diagram generating device 100 can be configured by using the data memory 112 shown in Fig. 8. However, these configured storage areas are not essential components within the network configuration diagram generating device 100, and may be areas provided in, for example, an external storage medium such as a USB (Universal Serial Bus) memory, or a storage device such as a database server located in the cloud.

[0055] The processing function units in each of the above units can be realized by reading and executing a program stored in the program memory 111B by the hardware processor 111A. Note that some or all of these processing function units may be realized in various other forms, including integrated circuits such as an application specific integrated circuit (ASIC) or a field-programmable gate array (FPGA).

[0056] The methods described in each embodiment can be stored as a program (software means) that can be executed by a computer on a recording medium such as a magnetic disk (floppy disk, hard disk, etc.), optical disk (CD-ROM, DVD, MO, etc.), or semiconductor memory (ROM, RAM, flash memory, etc.), and can also be distributed by transmitting it via a communication medium. The program stored on the medium also includes a configuration program that configures the software means (including not only execution programs but also tables or data structures) that the computer executes. The computer that realizes this device reads the program stored on the recording medium and, in some cases, configures the software means using the configuration program, and executes the above-mentioned processing by controlling the operation of this software means. The term "recording medium" as used herein is not limited to a storage medium for distribution, but also includes a storage medium such as a magnetic disk or semiconductor memory installed inside the computer or in a device connected via a network.

[0057] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0058] REFERENCE SIGNS LIST 100: Network configuration diagram generating device 11: Network configuration information input unit 12: Network configuration information storage unit 13: Placement information determination unit 14: Placement information storage unit 15: Placement information output unit

Claims

1. A position control device comprising: a setting unit that inputs information related to a plurality of nodes that can be displayed on a screen and at least one edge connecting two of the plurality of nodes, and sets a node by shifting a node belonging to a first layer among the plurality of nodes indicated by the input information so that the node is closer to a node belonging to a second layer different from the first layer; a calculation unit that calculates an attractive force exerted on the node belonging to the second layer by an edge connecting the node belonging to the second layer and the node set by the setting unit; and a control unit that controls the display position of the plurality of nodes on the screen based on the attractive force calculated by the calculation unit.

2. The position control device described in claim 1, wherein the calculation unit calculates a first vector representing a repulsive force occurring between the multiple nodes, a second vector representing an attractive force that the edge connecting nodes belonging to the same layer exerts on the nodes belonging to the same layer, and a third vector representing an attractive force that the edge connecting a node belonging to the second layer with a node set by the setting unit exerts on the node belonging to the second layer, and calculates a vector obtained by adding up the first, second, and third vectors, and the control unit controls the display positions of the multiple nodes on the screen based on the added vector calculated by the calculation unit.

3. The position control device according to claim 1, wherein the control unit controls the display positions of the plurality of nodes relating to layers higher than the physical layer on the screen based on the gravitational force calculated by the calculation unit.

4. A method performed by a position control device, comprising: inputting, by a setting unit of the position control device, information relating to a plurality of nodes that can be displayed on a screen and at least one edge connecting two of the plurality of nodes; and setting a node by shifting a node belonging to a first layer among the plurality of nodes indicated by the input information so that the node is closer to a node belonging to a second layer different from the first layer; calculating, by a calculation unit of the position control device, an attractive force exerted on the node belonging to the second layer by the edge connecting the node belonging to the second layer and the node set by the setting unit; and controlling, by a control unit of the position control device, the display positions of the plurality of nodes on the screen based on the attractive force calculated by the calculation unit.

5. The position control method described in claim 4, wherein the calculation unit calculates a first vector representing a repulsive force occurring between the plurality of nodes, a second vector representing an attractive force exerted on the node belonging to the same layer by the edge connecting nodes belonging to the same layer, and a third vector representing an attractive force exerted on the node belonging to the second layer by the edge connecting the node belonging to the second layer and the node set by the setting unit, and calculates a vector obtained by adding up the first, second, and third vectors; and the control unit controls the display positions of the plurality of nodes on the screen based on the added vector calculated by the calculation unit.

6. The position control method according to claim 4, wherein the control unit controls the display positions of the plurality of nodes relating to layers higher than the physical layer on the screen based on the gravitational force calculated by the calculation unit.

7. A position control processing program that causes a processor to function as each part of the position control device according to any one of claims 1 to 3.

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