JP2007094508A - Method and device for displaying trend graph - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a drawing time period and precisely display a graph. <P>SOLUTION: The method for displaying a trend graph extracts the maximum value and minimum value of data collected within a cyclic period of one minute for every ten minutes, and draws lines L (L1, L2...) connecting the maximum value with the minimum value within the ten minutes for every ten minutes in parallel with the vertical axis by making a horizontal axis as a time axis, a vertical axis as a data axis, and the length corresponding to ten minutes as the width W of the line. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a trend graph display method and apparatus for graphing and displaying changes in data collected at a predetermined period.

  Conventionally, facilities such as plants and buildings have been provided with a monitoring system for monitoring the state of equipment, the state of a room, and the like (see, for example, Patent Document 1). This monitoring system has a central monitoring device, and a controller is connected to the central monitoring device via a communication line. The controller is in charge of controlling each device, and collects and stores data indicating the operation state of the device and various data such as temperature and humidity in the facility at a predetermined cycle (for example, one minute cycle).

  There is an operator on the central monitoring device side. The operator can designate the data and display the trend graph on the display of the central monitoring device. For example, when temperature data of a desired room is specified, a data transmission request is sent to the controller in which the temperature data is stored. In response to the transmission request from the central monitoring device, the controller returns the specified temperature data to the central monitoring device. For example, when the trend graph display section (display target period) is 2 days, the temperature data for 2 days (all time series data for 2 days) stored in the controller in time series is stored in the central monitoring device. Return it. The central monitoring device acquires all the temperature data sent from the controller, and then displays the acquired temperature data on the display with the first axis (horizontal axis) as the time axis and the second axis (vertical axis) as the data axis. Are plotted with a broken line and displayed as a trend graph (see Patent Document 2 and Patent Document 3).

JP 2003-58247 A JP-A-5-303376 JP 2003-244146 A

  However, according to the conventional trend graph display method described above, for example, if data for a period of one minute is displayed as a graph for two days (48 hours), 2880 (60 × 48 = 2880) data are plotted, all of which are plotted. There is a problem that it takes a considerable time (about 10 seconds) to draw a trend graph.

  As one method for reducing the drawing time, for example, a method of extracting data every 10 minutes from 1-minute data, plotting the extracted data, and connecting them with a broken line is conceivable. However, in such a method, since data having a 1-minute period continuous in time series are simply extracted at intervals of 10 pieces, the phenomenon that the undulation of the trend disappears or appears occurs. The change cannot be accurately graphed and displayed.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a trend graph display method and apparatus capable of reducing both drawing time and accurate graph display. There is.

  In order to achieve such an object, the first invention (the invention according to claim 1), the maximum value and the minimum value of the data collected at a predetermined period within the predetermined time interval are extracted every predetermined time interval. Extraction step, a first time axis as a time axis, a second axis orthogonal to the first axis as a data axis indicating a data value, and a length corresponding to a predetermined time interval in the first axis as its line width, a predetermined time interval A drawing step for drawing a line connecting the maximum value and the minimum value within the predetermined time interval in parallel with the second axis is provided.

  According to the present invention, for example, assuming that the predetermined period is 1 minute and the predetermined time interval is 10 minutes, the maximum value and the minimum value of the 1-minute period data within 10 minutes are extracted every 10 minutes. A line connecting the value and the minimum value is drawn parallel to the second axis (data axis). In this case, the width of the line is a length corresponding to 10 minutes on the first axis (time axis). For example, if the length corresponding to 10 minutes in the first axis is 1 pixel, a line connecting the maximum value and the minimum value of the data in that pixel with a line width of 1 pixel per pixel is on the second axis. It is drawn in parallel.

  In the first invention, when one of the adjacent predetermined time intervals is the current predetermined time interval and the other is the previous predetermined time interval, the minimum value in the current predetermined time interval is greater than the maximum value in the previous predetermined time interval. In other words, the line drawn for the current predetermined time interval and the line drawn for the previous predetermined time interval may not be continuous. Assuming such a case, in the second invention (the invention according to claim 2), when the minimum value in the current predetermined time interval is larger than the maximum value in the previous predetermined time interval, the current predetermined time interval The minimum value is replaced with the maximum value in the previous predetermined time interval, and a line connecting the maximum value and the minimum value in the current predetermined time interval is drawn.

  In the first invention, when one of the adjacent predetermined time intervals is the current predetermined time interval and the other is the previous predetermined time interval, the maximum value in the current predetermined time interval is greater than the minimum value in the previous predetermined time interval. The line drawn for the current predetermined time interval and the line drawn for the previous predetermined time interval may not be continuous. Assuming such a case, in the third invention (the invention according to claim 3), when the maximum value in the current predetermined time interval is smaller than the minimum value in the previous predetermined time interval, the current predetermined time interval. The maximum value is replaced with the minimum value in the previous predetermined time interval, and a line connecting the maximum value and the minimum value in the current predetermined time interval is drawn.

  In the second invention, when the minimum value in the current predetermined time interval is larger than the maximum value in the previous predetermined time interval, the minimum value in the current predetermined time interval is replaced with the maximum value in the previous predetermined time interval. In order to draw a line connecting the maximum value and the minimum value in the current predetermined time interval, the line connecting the maximum value and the minimum value in the current predetermined time interval and the maximum value in the previous predetermined time interval are drawn. And the line connecting the minimum value are connected by the corners of the line. In this case, continuity is maintained, but the line width suddenly narrows in the middle, resulting in a distorted and difficult-to-see graph.

  Therefore, in the fourth invention (the invention according to claim 4), when the minimum value in the current predetermined time interval is larger than the maximum value in the previous predetermined time interval, the minimum value in the current predetermined time interval is set to the previous value. The maximum value within the predetermined time interval is replaced with a value obtained by subtracting the value α corresponding to the line width to draw a line connecting the maximum value and the minimum value within the current predetermined time interval. For example, when the line width is 1 pixel, α is 1 pixel, and when the line width is 2 pixels, α is 2 pixels, and the line connecting the maximum value and the minimum value within the predetermined time interval is The line connecting the maximum value and the minimum value within the previous predetermined time interval is connected with the same line width.

  In the third invention, when the maximum value in the current predetermined time interval is smaller than the minimum value in the previous predetermined time interval, the maximum value in the current predetermined time interval is replaced with the minimum value in the previous predetermined time interval. In order to draw a line connecting the maximum value and the minimum value in the current predetermined time interval, the line connecting the maximum value and the minimum value in the current predetermined time interval and the maximum value in the previous predetermined time interval are drawn. And the line connecting the minimum value are connected at the corners. In this case, continuity is maintained, but the line width suddenly narrows in the middle, resulting in a distorted and difficult-to-see graph.

  Therefore, in the fifth invention (the invention according to claim 5), when the maximum value in the current predetermined time interval is smaller than the minimum value in the previous predetermined time interval, the maximum value in the current predetermined time interval is set to the previous value. A line connecting the maximum value and the minimum value within the predetermined time interval is drawn by replacing the minimum value within the predetermined time interval with a value obtained by adding the value α corresponding to the line width. For example, when the line width is 1 pixel, α is 1 pixel, and when the line width is 2 pixels, α is 2 pixels, and the line connecting the maximum value and the minimum value within the predetermined time interval is The line connecting the maximum value and the minimum value within the previous predetermined time interval is connected with the same line width.

  The present invention can be implemented not as a trend graph display method but also as a trend graph display device. The inventions of claims 6, 7, 8, 9, and 10 of the present application relate to a trend graph display device to which the trend graph display method of claims 1, 2, 3, 4, and 5 is applied.

  According to the present invention, the first axis is the time axis, the second axis orthogonal to the first axis is the data axis, and the length corresponding to the predetermined time interval in the first axis is the line width. Since the line connecting the maximum value and the minimum value of the data collected at a predetermined period within the predetermined time interval is drawn parallel to the second axis, the number of lines to be drawn is reduced and the drawing time is shortened. In addition, it is possible to extract the maximum value and the minimum value from the data within a predetermined time interval and perform accurate graph display.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a main part of an example of a monitoring system used for implementing a trend graph display method according to the present invention.

  In the figure, 1 is a central monitoring device provided in the central monitoring room of the building, 2 is a controller distributed in the building, and 3 is equipment such as air conditioning equipment, heat source equipment, lighting equipment and the like. The central monitoring device 1 and the controller 2 are connected via a communication line 4.

  In this example, the controller 2-1 is provided for the air conditioning equipment 3-1, the controller 2-2 is provided for the heat source equipment 3-2, and the controller 2-3 is provided for the lighting equipment 3-3. It has been.

  The controller 2-1 is in charge of controlling each device of the air conditioning equipment 3-1, and also provides various data such as the data indicating the operation state of each device of the air conditioning equipment 3-1 and the room temperature of each room for 1 minute. Collected in cycles and stored in its own memory.

  The controller 2-2 is in charge of controlling each device of the heat source facility 3-2, and various data such as the data indicating the operation state of each device of the heat source facility 3-2 and the temperature of the heat source water are, for example, 1 minute cycle Collected and stored in its own memory.

  The controller 2-3 is in charge of controlling each device of the lighting equipment 3-3, and collects various data such as data indicating the operation state of each device of the lighting equipment 3-2 and electric energy at a cycle of 1 minute, for example. And store it in its own memory.

  FIG. 2 is a diagram showing an outline of the hardware configuration of the central monitoring apparatus 1. In the figure, 1-1 is a CPU, 1-2 is a RAM, 1-3 is a ROM, 1-4 is a storage device such as a hard disk, 1-5 to 1-7 is an interface, 1-8 is a display, 1- 9 is a keyboard, and 1-10 is a mouse.

  The CPU 1-1 obtains various input information given through the interfaces 1-5 to 1-7, and operates according to programs stored in the ROM 1-3 and the storage device 1-4 while accessing the RAM 1-2. . The storage device 1-4 stores a trend graph display program as a program unique to the present embodiment. The trend graph display program is provided in a state of being recorded on a recording medium such as a CD-ROM, for example, and is read from the recording medium and installed in the storage device 1-4.

[Embodiment 1]
Hereinafter, the processing operation of the CPU 1-1 according to the trend graph display program stored in the storage device 1-4 will be described.

  When the operator selects, for example, A0 point as a measurement point of analog data as a trend graph on the display 1-8, the CPU 1-1 sends a data transmission request to the controller 2 in which data of the A0 point is accumulated. send.

  In this embodiment, for example, a plan view of each floor of the building is displayed on the display 1-8, and names of various management points are displayed in the plan view. By selecting and specifying the point A0 on this plan view, a data transmission request is sent to the controller 2. In the present embodiment, it is assumed that the trend graph display section is defined as two days (48 hours).

 Upon receiving a data transmission request from the central monitoring device 1, the controller 2 stores data for two days of A0 points stored in time series in its own memory (48 hours of data collected in a one-minute cycle). (2880)) is returned to the central monitoring apparatus 1.

  The CPU 1-1 receives the data for 2 days of A0 point returned from the controller 2, and from the data for 2 days, the maximum of the data collected in the 1 minute cycle within 10 minutes every 10 minutes. Extract values and minimum values. That is, 10 minutes is set as one sampling period (predetermined time interval), and the maximum value and the minimum value of data within this sampling period are extracted. The extraction of the maximum value and the minimum value is performed by sequentially comparing the data of the 1 minute period within 10 minutes and determining the minimum and maximum each time.

  First, the first data D1 and the next data D2 within 10 minutes are compared, and if D1> D2, maximum = D1 and minimum = D2. Next, D3 is compared with the maximum, and if D3> maximum, the maximum = D3. Otherwise, D3 is compared with the minimum, and if D3 <minimum, the minimum = D3. This is sequentially performed on data having a 1-minute period within 10 minutes, thereby determining the maximum value and the minimum value within the 10 minutes.

  As shown in FIG. 3, the first axis (horizontal axis) is the time axis, the second axis (vertical axis) orthogonal to the first axis is the data axis indicating the data value, and the first axis corresponds to 10 minutes. The line L connecting the maximum value and the minimum value within the 10 minutes is drawn in parallel with the second axis (data axis) every 10 minutes with the length W to be processed as the line width. FIG. 4 shows an example of a trend graph (display interval: 48 hours) of data at point A0 drawn according to this drawing rule.

  In this trend graph, the number of lines to be drawn is greatly reduced and the drawing time is greatly reduced as compared with the case of connecting one-minute period data one by one with a broken line. For example, when connecting 1-minute data one by one with a broken line, a drawing time of about 10 seconds is required, whereas in the present embodiment, a drawing time of about 1 second is required. Further, in contrast to the conventional trend graph in which the diagonal lines are continuous, in the present embodiment, the vertical lines are continuous, and the drawing load is reduced even at the graphic driver level. In addition, since the maximum and minimum values of the data within 10 minutes are connected, the result is similar to the line connecting each data within 10 minutes one by one, and the trend undulation disappears or appears. This makes it possible to display an accurate graph without causing the phenomenon that

[Embodiment 2]
In the first embodiment described above, when one of the adjacent sampling periods (10 minutes) is the current sampling period and the other is the previous sampling period, the minimum value in the current sampling period is the maximum in the previous sampling period. The line drawn for the current sampling period and the line drawn for the previous sampling period may not be continuous.

  An example is shown in FIG. In FIG. 5A, S1 is the previous sampling period, and S2 is the current sampling period. In this case, the minimum value in the current sampling period S2 is larger than the maximum value in the previous sampling period S1, and the line L2 drawn for the current sampling period S2 and the previous sampling period S1 are drawn. The line L1 is not continuous.

  Assuming such a case, in the second embodiment, when the minimum value in the current sampling period S2 is larger than the maximum value in the previous sampling period S1, the minimum value in the current sampling period S2 is set to the previous value. The line L2 connecting the maximum value and the minimum value of the current sampling period S2 is drawn instead of the maximum value in the sampling period S1. As a result, as shown in FIG. 5B, the line L2 drawn for the current sampling period S2 and the line L1 drawn for the previous sampling period S1 become continuous.

[Embodiment 3]
In the first embodiment described above, when one of the adjacent sampling periods (10 minutes) is the current sampling period and the other is the previous sampling period, the maximum value in the current sampling period is the minimum in the previous sampling period. The line drawn for the current sampling period and the line drawn for the previous sampling period may not be continuous.

  An example is shown in FIG. In FIG. 6A, S1 is the previous sampling period, and S2 is the current sampling period. In this case, the maximum value in the current sampling period S2 is smaller than the minimum value in the previous sampling period S1, and the line L2 drawn for the current sampling period S2 and the previous sampling period S1 are drawn. The line L1 is not continuous.

  Assuming such a case, in the third embodiment, when the maximum value in the current sampling period S2 is smaller than the minimum value in the previous sampling period S1, the maximum value in the current sampling period S2 is set to the previous value. The line L2 connecting the maximum value and the minimum value of the current sampling period S2 is drawn instead of the minimum value in the sampling period S1. Thereby, as shown in FIG. 6B, the line L2 drawn for the current sampling period S2 and the line L1 drawn for the previous sampling period S1 become continuous.

[Embodiment 4]
In the second embodiment (FIG. 5), when the minimum value in the current sampling period is larger than the maximum value in the previous sampling period, the minimum value in the current sampling period is changed to the maximum value in the previous sampling period. In order to draw a line connecting the maximum and minimum values in the current sampling period, the line connecting the maximum and minimum values in the current sampling period and the maximum and minimum values in the previous sampling period The line connecting the values is connected at the corners of the line (FIG. 5B). In this case, continuity is maintained, but the line width suddenly narrows in the middle, resulting in a distorted and difficult-to-see graph.

  Therefore, in the fourth embodiment, when the minimum value in the current sampling period is larger than the maximum value in the previous sampling period, the line width is changed from the minimum value in the current sampling period to the maximum value in the previous sampling period. The value α corresponding to W is replaced with a value obtained by subtracting the value, and a line connecting the maximum value and the minimum value in the current sampling period is drawn.

  An example is shown in FIG. As shown in FIG. 7A, when the minimum value in the current sampling period S2 is larger than the maximum value in the previous sampling period S1, as shown in FIG. 7B, within the current sampling period S2. Is replaced with a value obtained by subtracting the value α corresponding to the line width W from the maximum value in the previous sampling period S1, and the line L2 connecting the maximum value and the minimum value in the current sampling period S2 is drawn. .

  For example, when the line width W is 1 pixel, α is 1 pixel (FIG. 7B), and when the line width W is 2 pixels, α is 2 pixels (FIG. 7C). The line L2 connecting the maximum value and the minimum value in the current sampling period S2 and the line L1 connecting the maximum value and the minimum value in the previous sampling period S1 are connected with the same line width. As a result, the line width is not suddenly reduced in the middle, and the trend graph is easy to see.

[Embodiment 5]
In Embodiment 3 (FIG. 6), when the maximum value in the current sampling period is smaller than the minimum value in the previous sampling period, the maximum value in the current sampling period is changed to the minimum value in the previous sampling period. In order to draw a line connecting the maximum and minimum values in the current sampling period, the line connecting the maximum and minimum values in the current sampling period and the maximum and minimum values in the previous sampling period The line connecting the values is connected at the corners of the line (FIG. 6B). In this case, continuity is maintained, but the line width suddenly narrows in the middle, resulting in a distorted and difficult-to-see graph.

  Therefore, in the fifth embodiment, when the maximum value in the current sampling period is smaller than the minimum value in the previous sampling period, the line width is changed from the maximum value in the current sampling period to the minimum value in the previous sampling period. The value α corresponding to W is replaced with an increased value, and a line connecting the maximum value and the minimum value in the current sampling period is drawn.

  An example is shown in FIG. As shown in FIG. 8A, when the maximum value in the current sampling period S2 is smaller than the minimum value in the previous sampling period S1, as shown in FIG. 8B, within the current sampling period S2. Is replaced with a value obtained by adding a value α corresponding to the line width W to a minimum value in the previous sampling period S1, and a line L2 connecting the maximum value and the minimum value in the current sampling period S2 is drawn. To do.

  For example, when the line width W is 1 pixel, α is 1 pixel (FIG. 8B), and when the line width W is 2 pixels, α is 2 pixels (FIG. 8C). The line L2 connecting the maximum value and the minimum value in the current sampling period S2 and the line L1 connecting the maximum value and the minimum value in the previous sampling period S1 are connected with the same line width. As a result, the line width is not suddenly reduced in the middle, and the trend graph is easy to see.

  In the above-described embodiment, in the description using FIGS. 5 to 8, the adjacent sampling period closer to the current time is the current sampling period S <b> 2, and the farther is the previous sampling period S <b> 1. However, even if the closer to the current time is the previous sampling period S1 and the farther is the current sampling period S2, the trend graph can be drawn in a short time with exactly the same rules.

  Normally, since a trend graph is drawn from the past to the present, the closer to the current time is the current sampling period S2, and the farther is the previous sampling period S1. As a special case, it may be possible to draw a trend graph from the present to the past. In this case, the one near the current time is the previous sampling period S1, and the far one is the current sampling period S2. To do. In addition, when the trend graph is displayed at once after drawing, the order of the current sampling period and the previous sampling period may be either.

  In the above-described embodiment, analog data has been described as an example. However, it is also possible to display the trend graph in a short time in the same manner with digital data indicating an operation state or the like. For example, if the ON state is “1” level data and the OFF is “0” level data, the ON / OFF level change within 10 minutes is the maximum within 10 minutes. A line connecting the value (“1” level) and the minimum value (“0” level) is drawn parallel to the data axis. FIG. 9 exemplifies a trend graph of digital data showing the operation state drawn in this way.

  Further, as a special rule, when the maximum value and the minimum value in the sampling period are equal and the states are continuous, the horizontal lines may be drawn at once instead of connecting the vertical lines one by one. In such a case, further speeding up can be realized by drawing a horizontal line. For example, when the data value does not change for 48 hours, the drawing is completed with one line.

  In the embodiment described above, the sampling period is 10 minutes and the data collection period is 1 minute, but it goes without saying that the present invention is not limited to this. Also, the trend graph display section is not limited to 48 hours.

It is a block block diagram which shows the principal part of an example of the monitoring system used for implementation of the trend graph display method which concerns on this invention. It is a figure which shows the outline of the hardware constitutions of the central monitoring apparatus in this monitoring system. It is a figure explaining the drawing rule (Embodiment 1) for every sampling period of the trend graph displayed on the display of a central monitoring apparatus. It is a figure which illustrates the trend graph (display area: 48 hours) of the data of A0 point drawn according to this drawing rule. FIG. 10 is a diagram illustrating a drawing rule according to the second embodiment. FIG. 10 is a diagram illustrating a drawing rule according to Embodiment 3. FIG. 10 is a diagram illustrating a drawing rule according to the fourth embodiment. FIG. 10 is a diagram for explaining a drawing rule according to the fifth embodiment. It is a figure which illustrates the trend graph (display area: 48 hours) of the digital data which shows the driving | running state drawn by the same drawing rule as analog data.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Central monitoring apparatus, 2 (2-1 to 2-3) ... Controller, 3 (3-1 to 3-3) ... Equipment, 1-1 ... CPU, 1-2 ... RAM, 1-3 ... ROM, 1-4 ... Storage device, 1-5 to 1-7 ... Interface, 1-8 ... Display, 1-9 ... Keyboard, 1-10 ... Mouse, 4 ... Communication line, L ... Line, W ... Line width, S1 ... last sampling period (previous predetermined time interval), S2 ... current sampling period (current predetermined time interval).

Claims (10)

An extraction step for extracting a maximum value and a minimum value of data collected at a predetermined period within the predetermined time interval for each predetermined time interval;
The first axis is the time axis, the second axis orthogonal to the first axis is the data axis indicating the data value, and the length corresponding to the predetermined time interval in the first axis is the line width. And a drawing step of drawing a line connecting the extracted maximum value and minimum value within the predetermined time interval in parallel to the second axis. The trend graph display method according to claim 1,
In the drawing step, one of the adjacent predetermined time intervals is the current predetermined time interval and the other is the previous predetermined time interval, and the minimum value in the current predetermined time interval is larger than the maximum value in the previous predetermined time interval. In this case, the minimum value in the current predetermined time interval is replaced with the maximum value in the previous predetermined time interval, and the line connecting the maximum value and the minimum value in the current predetermined time interval is drawn. Trend graph display method. The trend graph display method according to claim 1,
In the drawing step, one of the adjacent predetermined time intervals is the current predetermined time interval and the other is the previous predetermined time interval, and the maximum value in the current predetermined time interval is smaller than the minimum value in the previous predetermined time interval. In this case, the maximum value in the current predetermined time interval is replaced with the minimum value in the previous predetermined time interval, and the line connecting the maximum value and the minimum value in the current predetermined time interval is drawn. Trend graph display method. The trend graph display method according to claim 1,
In the drawing step, one of the adjacent predetermined time intervals is the current predetermined time interval and the other is the previous predetermined time interval, and the minimum value in the current predetermined time interval is larger than the maximum value in the previous predetermined time interval. In this case, the minimum value within the predetermined time interval is replaced with a value obtained by subtracting the value α corresponding to the line width from the maximum value within the predetermined predetermined time interval. A trend graph display method characterized by drawing the line connecting the two. The trend graph display method according to claim 1,
In the drawing step, one of the adjacent predetermined time intervals is the current predetermined time interval and the other is the previous predetermined time interval, and the maximum value in the current predetermined time interval is smaller than the minimum value in the previous predetermined time interval. In this case, the maximum value within the predetermined time interval is replaced with a value obtained by adding the value α corresponding to the line width to the minimum value within the predetermined predetermined time interval. A trend graph display method comprising: drawing the line connecting values. Extracting means for extracting the maximum value and the minimum value of data collected at a predetermined period within the predetermined time interval for each predetermined time interval;
The first axis is the time axis, the second axis orthogonal to the first axis is the data axis indicating the data value, and the length corresponding to the predetermined time interval in the first axis is the line width. And a drawing means for drawing a line connecting the extracted maximum value and minimum value within the predetermined time interval in parallel with the second axis. In the trend graph display device according to claim 6,
The drawing means sets one of the adjacent predetermined time intervals as the current predetermined time interval and the other as the previous predetermined time interval, and the minimum value in the current predetermined time interval is larger than the maximum value in the previous predetermined time interval. In this case, the minimum value in the current predetermined time interval is replaced with the maximum value in the previous predetermined time interval, and the line connecting the maximum value and the minimum value in the current predetermined time interval is drawn. Trend graph display device. In the trend graph display device according to claim 6,
The drawing means sets one of the adjacent predetermined time intervals as the current predetermined time interval and the other as the previous predetermined time interval, and the maximum value within the current predetermined time interval is smaller than the minimum value within the previous predetermined time interval. In this case, the maximum value in the current predetermined time interval is replaced with the minimum value in the previous predetermined time interval, and the line connecting the maximum value and the minimum value in the current predetermined time interval is drawn. Trend graph display device. In the trend graph display device according to claim 6,
The drawing means sets one of the adjacent predetermined time intervals as the current predetermined time interval and the other as the previous predetermined time interval, and the minimum value in the current predetermined time interval is larger than the maximum value in the previous predetermined time interval. In this case, the minimum value within the predetermined time interval is replaced with a value obtained by subtracting the value α corresponding to the line width from the maximum value within the predetermined predetermined time interval. A trend graph display device, wherein the line connecting the two is drawn. In the trend graph display device according to claim 6,
The drawing means sets one of the adjacent predetermined time intervals as the current predetermined time interval and the other as the previous predetermined time interval, and the maximum value in the current predetermined time interval is smaller than the minimum value in the previous predetermined time interval. In this case, the maximum value within the predetermined time interval is replaced with a value obtained by adding the value α corresponding to the line width to the minimum value within the predetermined predetermined time interval. A trend graph display device characterized by drawing the line connecting values.

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