Abstract:
Methods, computer program products, and systems adapted to aid in data analysis by graphically displaying current situation on the background of historical data density, Historical data density is represented by one or more contour plots. An indicator of how a current data point compares to the historical data may be placed on one or more of the data density graphs. In some examples, data falling outside a threshold contour of historical data density may represent a new or an abnormal situation, and such data and/or a contour plot having such data may be highlighted in a graphical display.

Description:
FIELD  
       [0001]     The present invention is related to the field of data analysis. More specifically, the present invention relates to graphical analysis of data using a graphical user interface.  
       BACKGROUND  
       [0002]     Statistical data related to business and technology operations can be readily amassed in great amounts using recent innovations. The sheer amount of data, however, can make it difficult for a user untrained in statistical techniques to grasp what a collection of data means and how historical data relates to present or recent situation. Graphical interfaces that allow greater access to and easier understanding of amassed data are in demand.  
       SUMMARY  
       [0003]     The present invention relates to methods, computer program products, and systems adapted to aid in data analysis by graphically displaying one or more graphs related to historical data density in conjunction with data from a given data point. In an illustrative example, a plurality of data density graphs are displayed, indicating historical data density for a plurality of variables. An indicator of how a data point compares to the historical data may be placed on one or more of the data density graphs. In some embodiments, data falling outside historical data density can represent a new or an abnormal situation; this may be highlighted in a graphical display.  
         [0004]     Computer program products and systems for performing similar methods are also described. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]      FIGS. 1A-1B  illustrate forming a two dimensional contour plot from a three dimensional figure;  
         [0006]      FIG. 2  shows graphical display of a plurality of data density plots at once;  
         [0007]      FIG. 3  shows graphical display of a data point marker superimposed on a plurality of data density plots;  
         [0008]      FIG. 4  shows graphical display of an abnormal data point by the use of an data point marker superimposed on a plurality of data density plots;  
         [0009]      FIG. 5  shows graphical display of an abnormal data point by the use of an data point marker superimposed on a plurality of data density graphs, including trajectory data; and  
         [0010]      FIG. 6  is a block diagram for an illustrative method. 
     
    
     DETAILED DESCRIPTION  
       [0011]     The following detailed description should be read with reference to the drawings. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention.  
         [0012]     As used herein, the term “data point” is used to refer to a data element having one or more dimensions. A data point may be represented graphically in several different ways depending upon the graphical format. Data points may relate to any type of data such as system state data, event data, outcomes, business events, etc. A data density function or graph may include, for example, a probability density/distribution function, a histogram, or other graph relaying information related to the density of data, often using multiple dimensions in so doing.  
         [0013]      FIGS. 1A-1B  illustrate the formation of a two dimensional contour plot from a three dimensional figure. Referring to  FIG. 1A , a cone shape  10  is illustrated. The cone shape  10  may be an illustration of a probability distribution mapping in two variables, with X and Y coordinates as shown, and P(x,y), being the joint probability distribution or probability density function, as a dependent variable represented as the height of the cone shape  10 . In case of normal data distribution in both x and y, the cone will be shaped according to the Gaussian curve.  
         [0014]     While the three dimensional image of  FIG. 1A  is nice for understanding an interrelationship in a system having only X and Y variables, additional variables cannot be effectively shown. In an illustrative embodiment of the present invention, the illustrated shape in  FIG. 1A  is converted into a simpler 2-dimensional image, as shown in  FIG. 1B . This is done by treating the cone shape  10  as a topography image, looking “down” from  12 , and slicing the cone shape  10  transversely, for example, as shown at  14 . The outer contours of the slices are then shown in  FIG. 1B , with line  14 ′ in  FIG. 1B  corresponding to the outer contour of slice  14  in  FIG. 1A . The result is a contour plot  16 . In some embodiments the lines in the contour plot  16  may have distinct colors, patterns or weights. Further, the spaces between the lines in the contour plot  16  may be distinctly shaded, colored, or patterned to differentiate between levels of probability. In the illustrative embodiment, distinct patterns have been used to differentiate different levels of probability.  
         [0015]     The P(x,y) surface can also have more than one peak, resulting in more than one contour centers as shown in  FIG. 2 , at contour plot  32 . The illustrative shape in  FIG. 1  is thus not intended to be limiting. Joint probability contours are one type of data density plot, and may represent historical data.  
         [0016]      FIG. 2  shows the graphical display of a plurality of data density plots at once. The display  20  shows combinations of two dimensional joint probability density functions in a multivariable system including Variable A  22 , Variable B  24 , Variable C  26 , and Variable D  28 . For example, contour plot  30  illustrates, using a plurality of lines  32 , the contours of a joint probability distribution plot, P(a,d), for variables A  22  and D  28 .  
         [0017]     In some embodiments, the plurality of plots  30  may be “normalized”, where normalizing the plots  30  indicates placing contour lines such that the contour lines provide consistent indications across several plots  30  of the relationship between a data point and historical data. The lines  32  within each plot  30  may, in some embodiments, have a preselected correspondence. For example, each line may represent a standard deviation or a required data percentile. In an illustrative example, standard deviation is used, and three contour lines are shown in each plot. In some embodiments, percentiles may be used to reflect historical data frequency. In an illustrative example, five contour lines are provided, one each at percentiles of 5%, 15%, 30%, 70%, 85%, and 95%. When the contour lines in each plot are normalized, this means that each plot is shown in the same way. Some embodiments use normalized contour lines in the plots  30 , while others do not; this may vary depending upon user preference.  
         [0018]     The graphical display  20  thus provides a graphical matrix of probability relationships. The display  20  may be generated using a probability density function or other suitable statistical approach.  
         [0019]     Display  20  may also include mirrored images of the contour plots shown, with the mirrored images shown on the lower right-hand side (not shown). Display  20  may be effected by the use of any suitable image display apparatus such as a computer monitor, a suitable screen display such as those used with laptop computers and/or graphing calculators, television, projector, etc. The display  20  may also take the form of a printed plot. The statistical analysis and graphical function used to construct the data for display  20  may be performed using any suitable computer-type device such as a personal computer, a calculator, or other computers, or may be performed with a more application specific device such as a microprocessor having suitable data inputs/outputs and, if desired, memory.  
         [0020]     It should be noted that in  FIGS. 2-5 , the illustrative graphs shown do not represent any particular data and are presented for illustrative purposes.  
         [0021]      FIG. 3  shows the graphical display of a data point superimposed on a plurality of data density plots. The display  50  includes a number of plots including plot  52 , with lines  54  indicating data density given the X-Y position in the plot  52 . A data point is indicated by marker  56  according to values corresponding to the data point. The data point is illustrated on several tiles of the graphical display, with each tile corresponding to another data density plot. It can be seen that in plot  52 , the data point  56  falls along or within several of the contour lines  54 . The position of data point  56  with respect to the contour lines  54  indicates how data point  56  fits into historical relationships between variables A and B. If the data point  56  is lying within the historical data density represented by the contour lines  54 , this may indicate that the data point  56  has similar behavior to at least some historical data. In some embodiments this may indicate, that circumstances associated with the data point are considered to be normal. If the data point  56  is lying outside the historical data density represented by the contour lines  54 , this indicates that the data point  56  does not have similar behavior as historical data. In some embodiments this may indicate that the situation is considered new, or abnormal,  
         [0022]      FIG. 4  shows the graphical display of a data point by the use of a data point marker superimposed on a plurality of data density graphs. Specifically, in  FIG. 4 , a plot  70  shows a data point marker  72  falling well away from distribution lines  74  which, in the plot  70 , indicates that the data point is outside usual historical relationships between this pair of variables. In the illustrative example, the plot  70  is highlighted by frame  76  to indicate that the data point may be considered as abnormal according to the probability distribution represented in plot  70 . A user can then determine that the data point is considered to be outside historical relationships. The user can also observe in which specific combination of variables is the pair relationship within or outside historical data density.  
         [0023]     In some embodiments, the user is able to move a cursor (for example using a mouse or other commands) and click on any of the plots shown in the display  50 . The user may also be allowed to select different variables to view in place of those already shown. In another embodiment, the user can select to view raw data for a data point, and/or may choose to view a different graph type for one or more variables.  
         [0024]     Instead of a frame  76 , the tile associated with the plot  70  may change colors, flash, etc., to highlight the plot  70 .  
         [0025]      FIG. 5  shows the graphical display of data point which is considered to be abnormal by the use of an data point marker superimposed on a plurality of data density graphs, including data point trajectory data.  FIG. 5  is the same as  FIG. 4  except that trajectory data is now shown. Specifically, superimposed on the plot  70  is line  80  that indicates a trajectory, over time, of data point maker  72 . This allows further diagnosis of the data point  72  by a user.  
         [0026]     While in  FIG. 5  the trajectory is only indicated in the plot  70  that indicates an abnormal data point, trajectory may be shown in the other plots as well. The trajectory may be shown in any suitable fashion, including, for example, a frame-by-frame trajectory, animation, or any suitable indication of previous positions such as that shown in  FIG. 5 .  
         [0027]      FIG. 6  is a block diagram for an illustrative method. The method  100  begins with a start block and proceeds to generate a data density plot, as shown at  102 . The step of generating a data density plot at  102  may be performed by any suitable computational method/device, including a computer. As indicated by block  104 , step  102  may be repeated to generate several data density plots.  
         [0028]     Next, one or more of the data density plots are displayed at once, as shown at  106 . For example, the plot(s) may be displayed on a computer screen or other suitable display for observation by a user. In some embodiments, the method may end here to allow a user to observe and obtain diagnostic information regarding the system-wide probability relationships as indicated by the use of several data density plots.  
         [0029]     In some embodiments, the method may continue to step  108 , where a marker representing data point values is superimposed upon one, several, or all of the data density plots that were displayed in step  106 . Again, the method may end here in some embodiments. In some embodiments, if the data point marker falls outside of a threshold contour, the contour plot in which the threshold is passed may be highlighted. A threshold contour may be defined in any suitable manner, and may depend upon the format of the variables. The threshold contour may represent a certain percentage of data density peak height, or may represent an absolute threshold for data density. Threshold contours may be set by the use of a normalization process or may be selected in light of conditions, system needs (i.e. safety precautions), or other suitable factors.  
         [0030]     The step of superimposing a marker for data point values at  108  may include determining whether the data point marker falls outside of a specified boundary on one or more contour plots. If so, then the step of superimposing a marker for data point values at  108  may further include highlighting or otherwise indicating which contour plots show the data point marker falling outside of a specified boundary. The method may also end after such analysis and highlighting.  
         [0031]     The step of superimposing a marker for data point values at  108  may also include displaying a trajectory for the data point marker. Again, in some embodiments, the method ends after this step.  
         [0032]     The method may continue to step  110 , where the user is allowed to manipulate one or more of the trajectory plots. Illustrative ways in which a user may manipulate the plotted data may include, for example, showing trajectory data for the data point marker, or focusing on a single plot of the plural data density plots that were displayed in step  106 . A user may also select to view further data such as raw or statistical data related to that shown in one or more of the probability distribution plots, or the user may observe different variables than those shown in the data density plots. The user may also choose to see a marker for a different data point. The method then ends, as indicated.  
         [0033]     Those skilled in the art will recognize that the present invention may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departures in form and detail may be made without departing from the scope and spirit of the present invention as described in the appended claims.