Abstract:
A system for displaying a tree map visualization including a processor, a memory device, and program code resident in the memory device. The program code is executable by the processor to prioritize data in a data set so as to associate a priority with respective elements of the data in the data set, to predefine a pattern that reflects a desired display pattern for the associated priority of the elements of the data in the data set, to generate the tree map visualization that positions within a display space, and to display the tree map visualization on a display device.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. patent application Ser. No. 10/664,556 entitled INTELLIGENT POSITIONING OF ITEMS IN A TREE MAP VISUALIZATION, filed Sep. 19, 2003, the entire disclosure of which is incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    As computer technology advances, computing systems have undertaken the management and processing of larger data systems. With data systems ranging from massive standalone databases to vast distributed networks, oftentimes the limiting factor in analyzing the state of a given system rests not with computing resources, but with the human operator. Specifically, though the computing system may aggregate vast quantities of data in near real-time, in many cases, a human being must visualize the compilation of data to draw effective conclusions from the visualization. Yet, the ability of the end user to digest compiled information varies inversely with the amount of data presented to the end user. Where the amount of compiled data becomes excessive, it can be nearly impossible for a human being to adequately analyze the data. 
         [0003]    In an effort to address the foregoing difficulties, tree-map visualization methods have been developed. Initially proposed by Brian Johnson and Ben Shneiderman in the paper, Johnson et al., Tree-Maps: A Space-Filling Approach to the Visualization of Hierarchical Information Structures, Dept. of Computer Science &amp; Human-Interaction Laboratory (University of Maryland June 1991), tree-map visualization techniques map “hierarchical information to a rectangular 2-D display in a space-filling manner” in which the entirety of a designated display space is utilized. Additionally, “[i]nteractive control allows users to specify the presentation of both structural (depth bounds, etc.) and content (display properties such as color mappings) information.” Tree-map visualization techniques can be compared in a contrasting manner to traditional static methods of displaying hierarchically structured information. 
         [0004]    According to conventional static methods, a substantial portion of hierarchical information can be hidden from user view to accommodate the view of the hierarchy itself. Alternatively, the entire hierarchy can be visually represented, albeit vast amounts of display space can be obscured, hence wasted, simply to accommodate the structure without regard to the hierarchical data in the hierarchy itself. In the tree-map visualization technique, however, sections of the hierarchy containing more important information can be allocated more display space while portions of the hierarchy which are deemed less important to the specific task at hand can be allocated less space. More particularly, in operation, tree-maps partition the display space into a collection of rectangular bounding boxes representing the tree structure. The drawing of nodes within the bounding boxes can be entirely dependent on the content of the nodes, and can be interactively controlled. Since the display space size is user controlled, the drawing size of each node varies inversely with the size of the tree, for instance the number of nodes. Thus, trees having many nodes can be displayed and manipulated in a fixed display space, yet still be visible even when dealing with 1 million objects. 
         [0005]      FIG. 1  illustrates a conventional tree map display  10 . As seen in  FIG. 1 , a  10  by  10  display grid is filled with bounding boxes  12  through  68  representing the display of a data set containing twenty-nine entries. Data values associated with the twenty-nine entries establish the size of the bounding boxes and the color of the box, as represented by the different cross-hatch patterns illustrated in  FIG. 1 . Thus, a first data value may establish the size of the bounding box, for example, market capitalization if the data set represents different stocks, and a second data value may establish the color of the bounding box, for example, the change in stock price. Thus, in the example illustrated in  FIG. 1 , the tree map display  10  is created from the data set of Table 1 below. 
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Exemplary Data 
               
             
          
           
               
                   
                 Bounding Box 
                 First Data Value 
                 Second Data Value 
               
               
                   
                   
               
             
          
           
               
                   
                 12 
                 20 
                 1 (no cross-hatch) 
               
               
                   
                 14 
                 12 
                 4 (diagonal left-right) 
               
               
                   
                 16 
                 8 
                 4 (diagonal left-right) 
               
               
                   
                 18 
                 8 
                 1 (no cross-hatch) 
               
               
                   
                 20 
                 8 
                 4 (diagonal left-right) 
               
               
                   
                 22 
                 6 
                 1 (no cross-hatch) 
               
               
                   
                 24 
                 6 
                 3 (diagonal right-left) 
               
               
                   
                 26 
                 4 
                 3 (diagonal right-left) 
               
               
                   
                 28 
                 4 
                 3 (diagonal right-left) 
               
               
                   
                 30 
                 4 
                 2 (vertical cross-hatch) 
               
               
                   
                 32 
                 2 
                 1 (no cross-hatch) 
               
               
                   
                 34 
                 1 
                 4 (diagonal left-right) 
               
               
                   
                 36 
                 1 
                 1 (no cross-hatch) 
               
               
                   
                 38 
                 1 
                 1 (no cross-hatch) 
               
               
                   
                 40 
                 1 
                 3 (diagonal right-left) 
               
               
                   
                 42 
                 1 
                 1 (no cross-hatch) 
               
               
                   
                 44 
                 1 
                 4 (diagonal left-right) 
               
               
                   
                 46 
                 1 
                 2 (vertical cross-hatch) 
               
               
                   
                 48 
                 1 
                 1 (no cross-hatch) 
               
               
                   
                 50 
                 1 
                 4 (diagonal left-right) 
               
               
                   
                 52 
                 1 
                 2 (vertical cross-hatch) 
               
               
                   
                 54 
                 1 
                 3 (diagonal right-left) 
               
               
                   
                 56 
                 1 
                 1 (no cross-hatch) 
               
               
                   
                 58 
                 1 
                 1 (no cross-hatch) 
               
               
                   
                 60 
                 1 
                 4 (diagonal left-right) 
               
               
                   
                 62 
                 1 
                 3 (diagonal right-left) 
               
               
                   
                 64 
                 1 
                 3 (diagonal right-left) 
               
               
                   
                 66 
                 1 
                 1 (no cross-hatch) 
               
               
                   
                 68 
                 1 
                 2 (vertical cross-hatch) 
               
               
                   
                   
               
             
          
         
       
     
         [0006]    A further example of the use of a tree map visualization is provided by Fidelity Investments&#39; map of the stock market (which may be found at activequote.fidelity.com/rtmews/market_map.phtml). In the Fidelity market map, the market is divided into sectors and the sectors are populated with bounding boxes for individual stocks. The size of the bounding boxes is based on the market capitalization of the stock and the color of the boxes are based on the price activity of the stock. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    Embodiments of the present invention provide for a system for displaying a tree map visualization including a processor, a memory device, and program code resident in the memory device. The program code is executable by the processor to prioritize data in a data set so as to associate a priority with respective elements of the data in the data set, where the associated priorities designate a desired sequence to the respective elements of the data set. The program code is further executable by the processor to predefine a pattern that reflects a desired display pattern for the associated priority of the elements of the data in the data set. The program code is additionally executable by the processor to generate the tree map visualization that positions within a display space, a combination of bounding boxes corresponding to the elements of the data in the data set and void regions where no information is displayed, such that each bounding box in the tree map visualization is arranged in priority order based upon the sequence designated by the priority associated with its corresponding element and the predefined pattern and the void regions fill in the remainder of the display space where no bounding box is present. The program code is also executable by the processor to display the tree map visualization on a display device. 
         [0008]    In further embodiments of the present invention, a system for displaying data from a data set in a tree map visualization is provided. The system comprises processor means for prioritizing the data in the data set so as to associate a priority with respective elements of the data in the data set. The associated priorities designate a desired sequence to the respective elements of the data set and predefining a pattern that reflects a desired display pattern for the associated priority of the elements of the data in the data set. The processor means further for generating the tree map visualization that positions within a display space, a combination of bounding boxes corresponding to the elements of the data in the data set and void regions where no information is displayed, such that each bounding box in the tree map visualization is arranged in priority order based upon the sequence designated by the priority associated with its corresponding element and the predefined pattern and the void regions fill in the remainder of the display space where no bounding box is present. The system further comprises display means for displaying the tree map visualization on a display device. 
         [0009]    In still further embodiments of the present invention, a computer program product for displaying data from a data set in a tree map visualization is provided. The computer program product comprises a computer-usable storage medium having computer readable program code embodied therewith. The computer readable program code comprises computer readable program code configured to prioritize the data in the data set so as to associate a priority with respective elements of the data in the data set, where the associated priorities designate a desired sequence to the respective elements of the data set. The computer readable program code further comprises computer readable program code configured to predefine a pattern that reflects a desired display pattern for the associated priority of the elements of the data in the data set. The computer readable program code additionally comprises computer readable program code configured to generate the tree map visualization that positions within a display space, a combination of bounding boxes corresponding to the elements of the data in the data set and void regions where no information is displayed, such that each bounding box in the tree map visualization is arranged in priority order based upon the sequence designated by the priority associated with its corresponding element and the predefined pattern and the void regions fill in the remainder of the display space where no bounding box is present. The computer readable program code also comprises computer readable program code configured to display the tree map visualization on a display device. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0010]      FIG. 1  is an illustration of the display of a set of data utilizing a conventional tree map. 
           [0011]      FIG. 2  is a block diagram of a data processing system suitable for use in embodiments of the present invention. 
           [0012]      FIG. 3  is a more detailed block diagram of aspects of a data processing system that may be used in embodiments of the present invention. 
           [0013]      FIG. 4  is an illustration of the display of a set of data of  FIG. 1  utilizing a tree map according to embodiments of the present invention. 
           [0014]      FIG. 5  is a flowchart illustrating operations according to embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. 
         [0016]    As will be appreciated by one of skill in the art, the present invention may be embodied as a method, data processing system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Furthermore, the present invention may take the form of a computer program product on a computer-usable storage medium having computer-usable program code embodied in the medium. Any suitable computer readable medium may be utilized including hard disks, CD-ROMs, optical storage devices, a transmission media such as those supporting the Internet or an intranet, or magnetic storage devices. 
         [0017]    Computer program code for carrying out operations of the present invention may be written in an object oriented programming language such as Java®, Smalltalk or C++. However, the computer program code for carrying out operations of the present invention may also be written in conventional procedural programming languages, such as the “C” programming language. The program code may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user&#39;s computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). 
         [0018]    The present invention is described in part below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
         [0019]    These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. 
         [0020]    The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
         [0021]    Embodiments of the present invention provide for displaying data in tree map format on an electronic display by prioritizing the data to be displayed and displaying the bounding boxes associated with the data in an order reflecting the prioritization. Such prioritized display of bounding boxes may provide a mechanism so as to add additional information to the display of the data so as to allow a user to more readily assess the information displayed. The priority criteria may be based on the data itself, associated data, a characteristic of the data itself and/or may be provided as metadata. 
         [0022]    Various embodiments of the present invention will now be described with reference to the figures.  FIG. 2  illustrates an exemplary embodiment of a data processing system  130  suitable for a server and network traffic associated with the replicated server in accordance with embodiments of the present invention. The data processing system  130  typically includes input device(s)  132  such as a keyboard, pointer, mouse and/or keypad, a display  134 , and a memory  136  that communicate with a processor  138 . The data processing system  130  may further include a speaker  144 , and an I/O data port(s)  146  that also communicate with the processor  138 . The I/O data ports  146  can be used to transfer information between the data processing system  130  and another computer system or a network. These components may be conventional components, such as those used in many conventional data processing systems, which may be configured to operate as described herein. 
         [0023]      FIG. 3  is a block diagram of data processing systems that illustrates systems, methods, and computer program products in accordance with embodiments of the present invention. The processor  138  communicates with the memory  136  via an address/data bus  248 . The processor  138  can be any commercially available or custom microprocessor. The memory  136  is representative of the overall hierarchy of memory devices, and may contain the software and data used to implement the functionality of the data processing system  130 . The memory  136  can include, but is not limited to, the following types of devices: cache, ROM, PROM, EPROM, EEPROM, flash memory, SRAM, and DRAM. 
         [0024]    As shown in  FIG. 3 , the memory  136  may include several categories of software and data used in the data processing system  130 : the operating system  252 ; the application programs  254 ; the input/output (I/O) device drivers  258 ; and the data  256 , which may include hierarchical data sets. As will be appreciated by those of skill in the art, the operating system  252  may be any operating system suitable for use with a data processing system, such as OS/2, AIX or System390 from International Business Machines Corporation, Armonk, N.Y., Windows95, Windows98, Windows2000 or WindowsXP from Microsoft Corporation, Redmond, Wash., Unix or Linux. The I/O device drivers  258  typically include software routines accessed through the operating system  252  by the application programs  254  to communicate with devices such as the I/O data port(s)  146  and certain memory  136  components. The application programs  254  are illustrative of the programs that implement the various features of the data processing system  130  and preferably include at least one application that supports operations according to embodiments of the present invention. Finally, the data  256  represents the static and dynamic data used by the application programs  254 , the operating system  252 , the I/O device drivers  258 , and other software programs that may reside in the memory  136 . 
         [0025]    As is further seen in  FIG. 3 , the application programs  254  may include a tree map module  260 . The tree map module  260  may carry out the operations described herein for displaying a tree map diagram of a data set, such as the tree map data  262 . While the present invention is illustrated, for example, with reference to the tree map module  260  being an application program in  FIG. 3 , as will be appreciated by those of skill in the art, other configurations may also be utilized. For example, the tree map module  260  may also be incorporated into the operating system  252 , the I/O device drivers  258  or other such logical division of the data processing system  130 . Thus, the present invention should not be construed as limited to the configuration of  FIG. 3  but encompasses any configuration capable of carrying out the operations described herein. 
         [0026]    One difficulty with tree map visualizations is that the tree map is created so as to utilize all of the available display area. As such, the location of bounding boxes in the tree map is typically established without reference to the nature of the underlying data. The bounding boxes are typically arranged to utilize all of the available display area. Accordingly, the location of items of interest to a user may change from map to map and related and/or important items may be spread out in the map depending on the distribution of bounding boxes that utilizes all of the available display area. 
         [0027]    Embodiments of the present invention provide prioritized display of the data for a tree map visualization so as to display data in the tree map in a predefined pattern that reflects the priority of the item displayed. For example, the data set of Table 1 may be prioritized for display. The determination of priority may be based on the data itself, for example, increasing or decreasing data value, may be determined based on data associated with the data for display, may be based on a characterization and/or classification of the nature of the data being displayed and/or may be specified as a separate priority value. As used herein, the term priority refers to a sequence for display of data and does not necessarily refer to a judgment as to the importance of the data. 
         [0028]    The predefined pattern for display based on priority may be any suitable pattern of display. For example, higher priority data may be displayed in an upper left hand corner of the tree map and lower priority data may be displayed in a lower right hand corner of the tree map. Thus, priority may decrease diagonally across the map from left to right and top to bottom. Alternatively, priority could increase or decrease diagonally and from top to bottom. Priority could also increase or decrease on a line by line basis with boxes closer to the left or right sides of a line having a higher priority. Furthermore, the particular pattern may take into account the way in which the data is prioritized so as to provide for a high utilization of the display area. These patterns of display based on a priority are provided as examples. Embodiments of the present invention should not be construed as limited to a particular pattern but is intended to encompass any pattern of display based on priority. 
         [0029]    Returning to the example of Table 1, Table 2 below reflects a prioritization of the data from Table 1. The prioritization illustrated in Table 2 is arbitrary, however, as discussed herein, prioritization may be analytically determined and/or user defined. The display of the prioritized tree map data according to certain embodiments of the present invention results in the tree map of  FIG. 4 . 
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 Exemplary prioritized data set 
               
             
          
           
               
                 Bounding Box 
                 First Data Value 
                 Second Data Value 
                 Priority 
               
               
                   
               
             
          
           
               
                 412 
                 20 
                 1 (no cross-hatch) 
                 1 
               
               
                 414 
                 12 
                 4 (diagonal left- 
                 4 
               
               
                   
                   
                 right) 
               
               
                 416 
                 8 
                 4 (diagonal left- 
                 5 
               
               
                   
                   
                 right) 
               
               
                 418 
                 8 
                 1 (no cross-hatch) 
                 6 
               
               
                 420 
                 8 
                 4 (diagonal left- 
                 7 
               
               
                   
                   
                 right) 
               
               
                 422 
                 6 
                 1 (no cross-hatch) 
                 8 
               
               
                 424 
                 6 
                 3 (diagonal right- 
                 9 
               
               
                   
                   
                 left) 
               
               
                 426 
                 4 
                 3 (diagonal right- 
                 10 
               
               
                   
                   
                 left) 
               
               
                 428 
                 4 
                 3 (diagonal right- 
                 2 
               
               
                   
                   
                 left) 
               
               
                 430 
                 4 
                 2 (vertical cross- 
                 11 
               
               
                   
                   
                 hatch) 
               
               
                 432 
                 2 
                 1 (no cross-hatch) 
                 12 
               
               
                 434 
                 1 
                 4 (diagonal left- 
                 13 
               
               
                   
                   
                 right) 
               
               
                 436 
                 1 
                 1 (no cross-hatch) 
                 14 
               
               
                 438 
                 1 
                 1 (no cross-hatch) 
                 15 
               
               
                 440 
                 1 
                 3 (diagonal right- 
                 16 
               
               
                   
                   
                 left) 
               
               
                 442 
                 1 
                 1 (no cross-hatch) 
                 17 
               
               
                 444 
                 1 
                 4 (diagonal left- 
                 3 
               
               
                   
                   
                 right) 
               
               
                 446 
                 1 
                 2 (vertical cross- 
                 18 
               
               
                   
                   
                 hatch) 
               
               
                 448 
                 1 
                 1 (no cross-hatch) 
                 19 
               
               
                 450 
                 1 
                 4 (diagonal left- 
                 20 
               
               
                   
                   
                 right) 
               
               
                 452 
                 1 
                 2 (vertical cross- 
                 21 
               
               
                   
                   
                 hatch) 
               
               
                 454 
                 1 
                 3 (diagonal right- 
                 22 
               
               
                   
                   
                 left) 
               
               
                 456 
                 1 
                 1 (no cross-hatch) 
                 23 
               
               
                 458 
                 1 
                 1 (no cross-hatch) 
                 24 
               
               
                 460 
                 1 
                 4 (diagonal left- 
                 25 
               
               
                   
                   
                 right) 
               
               
                 462 
                 1 
                 3 (diagonal right- 
                 26 
               
               
                   
                   
                 left) 
               
               
                 464 
                 1 
                 3 (diagonal right- 
                 27 
               
               
                   
                   
                 left) 
               
               
                 466 
                 1 
                 1 (no cross-hatch) 
                 28 
               
               
                 468 
                 1 
                 2 (vertical cross- 
                 29 
               
               
                   
                   
                 hatch) 
               
               
                   
               
             
          
         
       
     
         [0030]    As seen in  FIG. 4 , a tree map visualization is generated based on the first and second data values, the prioritization of those values and the pattern in which priority is displayed. In  FIG. 4 , higher priority items are placed closer to the top of the map and closer to the left side of the map. 
         [0031]    As seen in  FIG. 4 , in comparison to  FIG. 1  the sequence of the bounding boxes for the corresponding elements of the data set of Table 1 in the tree map  400  has changed. In  FIG. 4 , the reference numerals of the bounding boxes  412  to  468  correspond to those of  FIG. 1  increased by  400 . Thus, for example, the bounding box  412  corresponds to the bounding box  12  of  FIG. 1 , the bounding box  414  corresponds to the bounding box  14  of  FIG. 1 , etc. Because the bounding boxes are arranged in a prioritized pattern, the tree map of  FIG. 4  not only displays a visualization of the first and second data values, it also displays a visualization of a third value, the priority value. 
         [0032]    Utilizing the tree map  400  of  FIG. 4 , a user may quickly ascertain the priority relationship between the data represented by the tree map  400 . Furthermore, because the data is arranged in a predefined priority pattern, the user may also know where to look in the tree map  400  for the information that may be most critical to monitor. 
         [0033]    Because the bounding boxes  412  to  468  are arranged in priority order, it may not be possible to completely utilize the display area of the tree map  400 . Thus, the tree map  400  has void regions  480 ,  482  and  484  where no information is displayed. Accordingly, embodiments of the present invention provide a modified tree map where bounding boxes of data elements are arranged in a predefined priority pattern and where all of the available display area is not necessarily utilized to display a bounding box. 
         [0034]      FIG. 5  is a flowchart illustration that depicts operations for prioritized display on a tree map pursuant to embodiments of the present invention. As shown in  FIG. 5 , a data set of tree map data is obtained (block  500 ). The data in the tree map data set is prioritized so that a priority is associated with data elements in the data set (block  502 ). The tree map is then generated such that the bounding boxes of the elements of the data set are arranged in a predefined pattern based on the priority associated with the corresponding element (block  504 . 
         [0035]    The criteria for prioritizing the data from the tree map data set may be a statically defined criteria or may be a dynamically generated criteria. The data may be prioritized based on any suitable analysis of the data, for example, the data may be prioritized based on a series of threshold values. The priority criteria or priority values may be statically set, user specified and/or dynamically determined. The dynamic determination of priority may be provided based on an evaluation of the data values and/or a desired tree map characteristic. For example, the priority may be dynamically set based on an evaluation of the data set. 
         [0036]    As mentioned above, the priority of an element of the data set may be based on the values of data that is displayed in the tree map, data associated with the data that is displayed in the tree map and/or metadata associated with the tree map data set. In the first instance, the data may be prioritized based on one or more of the data values that are used in generating the tree map. For instance, in the stock market example, the data may be prioritized based on market capitalization and/or a minimum change in stock price. 
         [0037]    The data set could also be prioritized based on additional data associated with the data that generates the tree map. For instance, in the stock market example, the data may be prioritized based on stock market activity where the priority is based on trading activity of a stock. 
         [0038]    The data set could also be prioritized based on metadata (i.e. data about the data) associated with the data set that generates the tree map. For example, the data set could be prioritized based on deviation from a standard or average of values of the data in the data set. Similarly, the metadata may directly indicate a priority associated with elements of the data set. For instance, in the stock market example, stocks owned by a user and/or tracked by the user could be identified and prioritized based on whether a stock was owned, tracked and/or not prioritized. 
         [0039]    In further embodiments of the present invention, multiple priorities may be used to arrange the bounding boxes in the tree map. For example, right to left could indicate increasing value of a first priority category while bottom to top would indicate increasing priority in a second priority category. In such a case, the upper left corner would contain the bounding box with the highest priority in both categories. In such a case, a hierarchy of the priority categories may need to be defined so as to determine a location between to equally situated bounding boxes. 
         [0040]    Embodiments of the present invention have been illustrated with reference to a unique priority being assigned to each data element of the tree map data set. However, in further embodiments of the present invention, different data elements in the tree map data set may have the same priority. In such a case, the location of display within the priority pattern of bounding boxes having the same priority may be established arbitrarily or based on another criteria, such as to maximize display utilization or a second priority criteria. However, such bounding boxes will still be displayed in priority order with respect to bounding boxes having a higher or lower priority. Accordingly, the present invention should not be construed as limited to the assignment of unique priorities. 
         [0041]    The flowcharts and block diagrams of  FIGS. 2 ,  3  and  5  illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products for selectively controlling tree map graphical user interfaces according to various embodiments of the present invention. In this regard, each block in the flow charts or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be understood that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. 
         [0042]    In the drawings and specification, there have been disclosed typical illustrative embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.