JPH0927040A - Graph display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display a directed graph which is easy for a user to understand and makes it easy to obtain necessary information as to the graph display device which displays the directed graph, etc., representing the structure of a computer program graphically. SOLUTION: In the directed graph drawn with an arc being in call relation and a couple of nodes being a function name, a segment which is part of the straight line connecting the center points C and C in the frames of the couple of nodes 3 and 6 and has its start point and end point positioned on adjacent edges of the couple of nodes 3 and 6 is displayed as an arc (6). Consequently, the start and end point of the arc (6) are made always present on the adjacent edges of the connected nodes 3 and 6 to eliminate such trouble that the nodes 3 and 6 in the connection relation and the arc (6) are displayed overlapping with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graph display device, and in particular, is suitable for use in a graph display device for displaying a directed graph that graphically represents the structure of a computer program in the development and maintenance of the computer program. .

[0002]

2. Description of the Related Art Conventionally, some graph display devices graphically display the structure of a program by nodes and arcs or edges to assist a user such as a programmer to easily understand the structure of the program. One of the display methods is called a directed graph. The directed graph will be described below. In this specification, a function name is described as a node and a call relationship is described as an arc in a directed graph.

FIG. 8 is a diagram showing an example of the directed graph. In the example of FIG. 8, the directed graph has 7 nodes and 8 nodes.
It is composed of a book arc. Four arcs are connected to the node 1. Here, arc is node 2, arc is node 5, arc is node 3
In addition, the arcs are connected to the nodes 4, respectively.

The node 2 is executed in the arc calling relationship from the node 1. Similarly, the node 5 is executed in the arc calling relationship. The node 3 is executed in the arc calling relationship from the node 1, and then the node 5 is executed in the arc calling relationship. In this way, the nodes connected in an arc relationship are sequentially executed.
However, not all arcs and nodes described in the directed graph are executed, and only necessary ones are executed according to the program.

By the way, in FIG. 8, each arc connects the sides of two nodes. That is, FIG.
As shown in (a), each node has an input side 31 and a side 61 to which the arc end point is input, and an output side 32 and a side 62 to which the arc start point is output. Arc is input or output to.

[0006]

By graphically representing the structure of the source program by the directed graph, the structure of the program can be easily understood. In particular, to analyze the program,
If you want to check the connection of a specific function,
We need to keep track of the nodes and arcs in a directed graph.

However, the directed graph shown above is an extremely simple example, and the larger the program becomes and the more complicated it becomes, the more nodes and arcs become and the more complicated it becomes visually. This violates the original purpose of the directed graph to provide a display with good visibility and easy for the user to understand.

Further, the arc does not always exist in a fixed direction, and for example, as shown in FIG. 9B, the arc may return from the node 6 to the node 3. In that case, in the conventional graph display device, when an arc is connected from the output side edge 62 of the node 6 to the input side edge 31 of another node 3, the node and the arc overlap each other, and it is described inside the node. There is a problem that the visibility of information and the like decreases. In particular, the number of nodes and arcs increases,
When the directed graph is complicatedly expressed, the visibility is extremely deteriorated.

The present invention has been made in view of the above circumstances, and is a graph display that allows a user to display a directed graph that is easy to understand and can obtain necessary information easily. The purpose is to provide a device.

[0010]

A graph display device of the present invention is a graph display device for displaying a software structure as a graph using nodes and arcs, and a straight line connecting specific points in each frame of a pair of nodes. A line segment whose start and end points are located on the outer edges of the pair of adjacent nodes is displayed as the arc.

Another feature of the present invention is that the specific point is a center point of the node.

Another feature of the present invention is that, in a graph display device that graphically displays the structure of software using nodes and arcs, a table of center points of a pair of nodes connected by the arcs is displayed. The center coordinate calculating means for obtaining each, the intersection calculating means for obtaining the intersection of the line segment connecting the center points obtained by the center coordinate calculating means and the pair of nodes, and the two intersections obtained by the intersection calculating means Display means for displaying a line segment starting from and ending at as the arc.

Another feature of the present invention is that, in a graph display device for displaying a software structure in a graph using nodes and arcs, a list of all arcs connected to each node displayed in the graph is displayed in each node. Arc list holding means for holding each, node selection means for selecting an arbitrary node from the above each node, all arcs connected to the node selected by the node selection means, refer to the arc list holding means A pair of nodes including the node selected by the node selecting means, and coordinate calculating means for calculating the coordinates of the node selected by the node selecting means and the arc connected to the node. Is a part of a straight line connecting between specific points in each frame, and its start point and end point are adjacent to the above pair of nodes. A line segment located on earthenware pots outer edge, characterized in that to display asking for each arc extracted by the arc extraction means.

Another feature of the present invention is that it further comprises display control means for changing the display form of the arc extracted by the arc extracting means to the display form of another arc. .

Another feature of the present invention is that it further comprises display control means for displaying the attribute of the node selected by the node selecting means and the attribute of the arc extracted by the arc extracting means. It is characterized by that.

Another feature of the present invention is that in a graph display device for displaying a software structure in a graph using nodes and arcs, a list of all nodes connected to each arc displayed in the graph is displayed as an arc. Refer to the node list holding means for holding the node list holding means for each, the arc selection means for selecting an arbitrary arc from each of the arcs, and all the nodes connected to the arc selected by the arc selection means And a display control unit for changing the display form of the node extracted by the node extraction unit from the display form of another node.

Another feature of the present invention is that it further comprises display control means for displaying the attribute of the arc selected by the arc selecting means and the attribute of the node extracted by the node extracting means. It is characterized by that.

[0018]

Since the present invention comprises the above technical means, the start point and the end point of each arc displayed in the graph are displayed so as to always be located on the adjacent outer edges of the pair of connected nodes. Irrespective of the direction of the arc or arc, the node and arc will not be displayed in an overlapping manner.

According to another feature of the present invention, since the display form of the arc extracted by the arc extracting means is changed from the display form of the other arc, the arc connected to the node selected by the user The other arcs can be easily distinguished, and the arc connecting to the selected node can be confirmed at a glance.

According to another feature of the present invention, since the attribute of the node selected by the node selecting means and the attribute of the arc extracted by the arc extracting means are displayed, details of each node and each arc are displayed. It becomes possible for the user to know various information.

According to another feature of the present invention, the display form of the node connected to the arc selected by the arc selecting means is changed from the display form of another node.
The node connected to the arc selected by the user and the other nodes can be easily identified, and the node connected to the selected arc can be immediately confirmed.

According to another feature of the present invention, since the attribute of the arc selected by the arc selecting means and the attribute of the node extracted by the node extracting means are displayed, details of each arc and each node are displayed. It becomes possible for the user to know various information.

[0023]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the graph display device according to this embodiment, FIG. 2 is a flow chart showing the operation of the graph display device according to this embodiment, and FIGS.
FIG. 7 is a diagram showing a display example of a directed graph according to the present embodiment.

First, a method of displaying a directed graph according to the first embodiment of the present invention will be described with reference to FIGS. The program structure itself of the directed graph shown in FIG. 3 is the same as the program structure of the directed graph of FIG. 8 described above. However, in the directed graph display according to this embodiment, the arc drawing method is different from the conventional one.

The common point between the arc display according to the present embodiment and the conventional arc display is that the arc has a start point and an end point, and nodes having a call relationship are connected by the arc and the end point thereof is connected. Is to have an arrowhead. The program is executed from the start point side node to the end point side node.

On the other hand, the features of the arc display according to this embodiment are as follows. That is, while the conventional arc is connected from the output side edge of a node to the input side edge of another node, the arc of the present embodiment, as shown in FIG. It means that the respective center coordinates C, C are connected, and that the start point and the end point exist on the adjacent outer edges of each node.

FIG. 4 is a diagram showing in detail the positional relationship of such an arc drawing method. That is, each node does not have the conventional concept of an input-side edge and an output-side edge, and the start point and the end point of the arc move on the outer edge of each node according to the coordinates of the two connecting nodes. Therefore, even when the direction of the arc is from the node 6 to the node 3, the node and the arc are not overlapped and displayed as in the conventional case, and the visibility is improved.

As a method of performing such drawing, the center coordinates of two nodes to be connected are respectively obtained, and the intersection of the line segment connecting the center points and the outer edge of each node is calculated, thereby The intersection may be determined as the starting point and the ending point of the arc.

The following advantages can be further obtained by using such a drawing method. For example, when analyzing or changing a program, it is assumed that the node 3 shown in FIG. 3 is to be moved to another place to form a graph structure. In this case, as shown in FIG. 5, when the node 3 is selected and moved to the upper right direction of the node 4, the arc is always calculated so as to connect the center coordinates of the pair of nodes. The arcs of the book move on the outer edges of the nodes to which they connect, and are consequently displayed as arc, arc, arc in FIG.

As is apparent from the above, in the conventional drawing method, the visibility is lowered because the arc and the node 1 and the node 3 are displayed at the overlapping position, whereas in the present embodiment, the visibility is reduced. Since these are not displayed in the overlapping position, it is possible to prevent the visibility from being lowered.

Further, the present embodiment is characterized in that the display form of the selected node and the arc connected to the node is changed. That is, the selected node and the arc connected to the node are displayed in a different color tone and line type from the other unselected nodes and arcs. As a result, the selected node or arc can be confirmed at a glance.

At this time, for example, as shown in FIG. 5, by further changing the display form between the arc input to the selected node 3 and the arc output from the node 3, it is possible to select the input arc or the output arc. Can be made easier to understand.

In the example of FIG. 3, a part of the arc is on the lower surface of the node 3, and that part is not displayed. Also in the example of FIG. 5, a part of the arc is hidden under the node 4 and the part is not displayed. However, it is possible to further improve the visibility by displaying the arc connected to the selected node as being on the upper surface of the node.

The procedure for performing the above drawing method will be described with reference to the flowchart of FIG. The flowchart of FIG. 2 shows an example of selecting a desired node and moving it to another place, and the processing when the node is selected will be described.

When a user selects a node, the node number is first acquired (step 1). The node number is for identifying each node, and each node has a different number or name. Then
The coordinates of the destination of the node are calculated (step 2), the node is erased from the position where the node currently exists, and at the same time, the node is redrawn to a new destination (step 3). At this time, the display form is changed as described above as needed.

Next, the number n of all arcs connected to the selected node is acquired (step 4). This is a numerical value for counting in order to repeatedly draw all the arcs connected to the selected node, and is obtained by calculating the number of arcs in the arc list described later.

The drawing of an arc is similar to the drawing of a node.
First, the arc number is acquired (step 5), the coordinates of the new arc are calculated according to the above-mentioned law (step 6), and the arc is erased from the position where the arc is currently present, and at the same time the arc is re-registered to the new destination. Draw (step 7). At this time, whether the arc is an arc input to the node or an arc output to the node is identified, and the display form is changed. Then, the processing of steps 5 to 7 is repeated until all arcs are redrawn (step 8,
9).

Next, the structure of the apparatus will be described. FIG. 1 shows the configuration of the graph display device according to this embodiment. As shown in FIG. 1, the graph display device of the present embodiment is roughly configured by connecting a display device 2, an input device 3, an output device 4 and a storage device 5 to a central processing unit 1.

For example, the display device 2 is composed of a monitor such as a CRT and a liquid crystal display, and the input device 3 is composed of input devices such as a keyboard and a mouse. The output device 4 is composed of a printer, a plotter, etc., and the storage device 5 is composed of a floppy disk, a hard disk, a magneto-optical disk, etc.

The central processing unit 1 controls the main operation of the graph display device, and also controls the above-mentioned devices 2 to 5 connected to it. The central processing unit 1 has a selection processing unit 11 as a node selection unit, an arc list holding unit 12, an arc extraction processing unit 13, a coordinate calculation processing unit 14, and a display control unit 15. Less than,
Each part will be described.

The selection processing unit 11 performs a process of selecting a node instructed by the user using the input device 3 from each node in the directed graph. Specifically, for example, when the input device 3 is composed of a mouse and the mouse pointer 16 is displayed in the graph display screen as shown in FIG. 5, the mouse pointer 16 is moved to a desired node and the mouse button is moved. By clicking, the node on which the mouse pointer 16 is placed is selected.

The arc list holding unit 12 holds a list of arcs connected to each node for each node, and is connected by the numbers of all arcs connected to each node and those arcs. The center coordinates of the node are described.

The arc extraction processing section 13 includes a selection processing section 11
All arcs connected to the selected node are extracted from the directed graph by referring to the arc list for the node selected in. At the time of the extraction, the arc extraction processing unit 13 also acquires the center coordinates of the nodes connected by the extracted arc from the arc list.

The arc extracted by the arc extraction processing unit 13 is recalculated by the coordinate calculation processing unit 14 as a straight line connecting the center coordinates of a pair of mutually connected nodes. If the node selected with the mouse is
If the user has moved to another position, first the center coordinates of the destination node are calculated, and then the straight line connecting the center coordinates is calculated.

The coordinate calculation processing section 14 further calculates the intersection of the straight line calculated as described above and the frame of the pair of nodes. These intersections are the starting and ending points of the arc. As described above, the coordinate calculation processing section 14 includes the central coordinate calculating means and the intersection calculating means.

The display control unit 15 includes the coordinate calculation processing unit 1 described above.
The starting point and the ending point of the arc calculated in 4 are connected to draw the arc. At the time of this drawing, the display control unit 15 performs processing of adding an arrowhead to the end point of the arc or changing the color tone according to the direction of the arc. The display control unit 15 also performs a process of changing the display form of the arc extracted by the arc extraction processing unit 13.

The result finally processed by the display control unit 15 is displayed on the display device 2 or output to the output device 4. It may also be stored in the storage device 5. By performing such a series of processing at high speed, when the user selects the desired node with the mouse and moves it to the desired position (drag and drop), the arc causes the node to move. It can be displayed as if moving along the outer edge of.

Next, a second embodiment of the present invention will be described.
FIG. 6 is a diagram showing an example of a screen display according to the second embodiment. As mentioned above, each node is a function and some are called many times in the program.
Some are rarely called. As described above, each node has attributes such as a function name and the number of calls, and it is very convenient to be able to refer to these attributes when analyzing or changing a program.

Therefore, in the present embodiment, when a node is selected, the attributes of the node and the arcs connected to the node are displayed so that detailed information about each node and the arc can be displayed by the user. I can tell you. Such display control is performed by the display control unit 15 in FIG.

FIG. 6 shows an example in which a directed graph and the attributes of nodes and arcs are simultaneously displayed on one screen 20. That is, mouse pointer 1
When the node 3 is selected using 6, the attributes of the node 3 and the arcs connected to it are displayed in the attribute display frame
7 is displayed. At this time, the attributes of the node 3 are displayed in the node attribute frame 18, and the attributes of arc and are displayed in the arc attribute frame 19.

Next, a third embodiment of the present invention will be described.
In the above examples, the case where the user selects a node has been described. However, when the program is large-scale and complicated, arcs are innumerably mixed, and it becomes difficult to understand which arc is connected to which node.

Therefore, in this embodiment, the user can select an arc, and when the arc is selected, the display form of the pair of nodes connected to the arc is changed. , The node connected to the selected arc can be confirmed immediately.

FIG. 7 is a diagram showing the structure of the graph display device according to the third embodiment. In FIG. 7, the selection processing unit 21 as an arc selection unit performs processing of selecting an arc designated by the user using the input device 3 from each arc in the directed graph. This selection process is the first
This can be performed in the same manner as the node selection processing described in the above embodiment.

The node list holding unit 22 holds a list of all nodes connected to each arc for each arc. The node extraction processing unit 23 refers to the node list for the arc selected by the selection processing unit 21 and extracts all the nodes connected to the selected arc from the directed graph.

The coordinate calculation processing section 24 uses the nodes extracted by the node extraction processing section 23 to recalculate the arc selected by the selection processing section 21 as a straight line connecting the center coordinates of a pair of nodes. Then, the intersections of the thus calculated straight line and the frame of the pair of nodes are calculated, and these intersections are set as the start and end points of the arc.

The display control unit 25 includes the coordinate calculation processing unit 2
The starting point and the ending point of the arc calculated in 4 are connected to draw the arc. The display control unit 25 also includes the node extraction processing unit 2
The display form of the node extracted in 3 is controlled so as to be displayed differently from the display forms of the other nodes. Also, the second
Similar to the embodiment described above, it is possible to obtain detailed information by displaying the attributes of the selected arc or node.

Although some embodiments have been described above, the graph display device can be constructed by combining these embodiments.

A pointing device such as a mouse is usually considered as a selection means for selecting a node or an arc, but if a number or name for identifying the node or arc is displayed, the number can be read from the keyboard. A desired node or arc can be selected by inputting or a name.

A recursive arc output from one node and input to the same node can be improved in visibility by using an arc-shaped arc.

[0060]

As described above, the present invention is a part of a straight line connecting specific points in each frame of a pair of nodes, and its start point and end point are located on the adjacent outer edges of the pair of nodes. Since the line segment to be displayed is displayed as the above arc, the node and the arc can be prevented from overlapping each other regardless of the position of the node or the direction of the arc, and the visibility of the node and the arc is significantly improved. Can be improved. This allows the user to easily understand the structure of the program.

According to another feature of the present invention, the display form of the arc extracted by the arc extracting means is changed to the display form of another arc, so that the user connects to the selected node. The arc can be confirmed at a glance, and the visibility of the arc can be further improved.

According to another feature of the present invention, since the attribute of the node selected by the node selecting means and the attribute of the arc extracted by the arc extracting means are displayed, details of each node and each arc are displayed. This makes it possible for the user to know such information at any time, making it easier to understand the structure of the program.

According to another feature of the present invention, the display form of the node connected to the arc selected by the arc selecting means is changed from the display form of another node.
The user can immediately confirm the node connected to the selected arc, and the visibility of the node can be further improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a graph display device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of the graph display device according to the first embodiment.

FIG. 3 is a diagram showing a display example of a directed graph according to the first embodiment.

FIG. 4 is a diagram for explaining a method of arc display using the present invention.

FIG. 5 is a diagram showing another display example of the digraph according to the first embodiment.

FIG. 6 is a diagram showing a display example of a directed graph according to a second embodiment.

FIG. 7 is a block diagram showing a configuration of a graph display device according to a third embodiment of the present invention.

FIG. 8 is a diagram showing a display example of a conventional directed graph.

FIG. 9 is a diagram for explaining a conventional arc display method.

[Explanation of symbols]

 1 central processing unit 2 display device 3 input device 4 output device 5 storage device 11 selection processing unit 12 arc list holding unit 13 arc extraction processing unit 14 coordinate calculation processing unit 15 display control unit 16 mouse pointer 17 attribute display frame 18 node attribute frame 19 arc attribute frame 20 display screen 21 selection processing unit 22 node list holding unit 23 node extraction processing unit 24 coordinate calculation processing unit 25 display control unit 31, 61 node input side 32, 62 node output side C node center coordinates

Claims (8)

[Claims] 1. A graph display device for displaying a software structure as a graph using nodes and arcs, which is a part of a straight line connecting specific points in each frame of a pair of nodes, and whose start and end points are A graph display device, wherein a line segment located on an outer edge of the pair of adjacent nodes is displayed as the arc. 2. The graph display device according to claim 1, wherein the specific point is a center point of the node. 3. A graph display device for displaying a software structure as a graph using nodes and arcs, wherein center coordinate calculation means for respectively obtaining a coordinate table of each center point of a pair of nodes connected by the arcs, An intersection point calculating means for obtaining an intersection point of the pair of nodes and a line segment connecting the respective center points obtained by the center coordinate calculating means, and a line segment having the two intersection points obtained by the intersection point calculating means as a start point and an end point. A graph display device comprising: display means for displaying the arc. 4. A graph display device for displaying the software structure in a graph using nodes and arcs, and arc list holding means for holding a list of all arcs connected to each node displayed in the graph for each node. A node selecting means for selecting an arbitrary node from the nodes, and an arc extracting means for extracting all arcs connected to the node selected by the node selecting means with reference to the arc list holding means, A node selected by the node selecting means and a coordinate calculating means for calculating the coordinates of an arc connected to the node, and between the specific points in each frame of the pair of nodes including the node selected by the node selecting means A line segment that is a part of the connecting straight line and whose start and end points are located on the outer edges of the pair of nodes that are adjacent to each other is Graph display device which is characterized in that to display asking for each arc extracted by chromatography click extraction means. 5. The graph display device according to claim 4, further comprising display control means for changing a display form of the arc extracted by the arc extracting means to a display form of another arc. . 6. The display control means for displaying the attribute of the node selected by the node selecting means and the attribute of the arc extracted by the arc extracting means. Alternatively, the graph display device according to item 5. 7. A graph display device for displaying a software structure as a graph using nodes and arcs, and node list holding means for holding a list of all nodes connected to each arc displayed in the graph for each arc. Arc selection means for selecting an arbitrary arc from the respective arcs, node extraction means for extracting all nodes connected to the arc selected by the arc selection means with reference to the node list holding means, and A graph display device, comprising: display control means for changing a display form of a node extracted by the node extracting means to a display form of another node. 8. The display control means is further provided for displaying the attribute of the arc selected by the arc selecting means and the attribute of the node extracted by the node extracting means. The graph display device described in.