Abstract: An interactive data interpretation tool is disclosed for enabling the identification of the position of features in a multidimensional data set, the tool comprising means for displaying an image representing a 2-D slice of the data set; and user input means for causing the storage of the position of a feature in the displayed image, characterized in that the 2-D slice can be displayed as part of a projection of a 3-D image, the third dimension of which corresponds to one of the other dimensions of the data set, the tool comprising means operable in response to a predetermined user input operation to cause the co-ordinate of the currently displayed 2-D slice in the third dimension of the 3-D image to be incremented, and the positions in the 3-D image of any features identified in the previously displayed slice to be indicated. The invention finds particular application to the interpretation of seismological data sets. Other applications include oceanographic and medical imaging data sets.

Abstract: A system for electronically developing an image captured on a film with two or more image capture layers. A developing solution is applied to the film and the film is illuminated by two lights on opposing surfaces. A scanner captures the light reflected from the film by each light source. The two digital images are combined on a pixel-by-pixel basis to form a final image. An alternate embodiment includes a third scanner to capture light transmitted through the film in order to form a third digital scan image which is then combined on a pixel-by-pixel basis with the other two images to form the final image. The invention provides a method for creating an image digitally without first creating an image in the film itself.

Abstract: Communicating the failure of a master process controlling one or more shared resources to all process sharing the resources. A shared resource control file is established that contains the identities of all sharing processes. Master process failure triggers a race to establish exclusive access over the shared control file. The new master reads shadow address data from the old shared control file, marks it as invalid and establishes a new control file based on renewed registrations from the sharing processes. The master process maintains the sharing process list as processes begin and end sharing.

Abstract: A computer graphics system simultaneously stores graphical storage areas of variable size in a two-dimensionally addressed graphics memory. The storage areas contain data corresponding to two-dimensional graphical images such as, for example, texture maps, mip maps, bit maps, or fonts. The graphics system manages the storage areas within the graphics memory using a quadtree that indicates the current storage state thereof. Using the quadtree, a memory manager divides the graphics memory address space into a first level of quadrants of equal two-dimensional size. The size of a storage area to be placed into the memory is compared with the size of the first level quadrants. If size is equal, then the storage area is placed into one of the quadrants. Otherwise, the memory manager further subdivides the graphics memory into quadrants on one or more descending levels as necessary to store the storage area within.

Abstract: A method for generating a multisided patch in which the expression form of each boundary curve and topology of the curve network can freely be set, curve formulae can be simply input, and high continuity. By inputting data of boundary curves to multisided patch generator via editing means which generates and edits curves, and blending sweep surfaces in two stages, a free-form surface is generated as a surface interpolating them. That is, data of a plurality of boundary curves is inputted to multisided patch generator, each given curve is swept by sweeping means along the curves intersecting it to generate surfaces, and the surfaces are blended by blending means in two stages, thereby generating a free-form surface.

Abstract: A method, system and process for allowing identical server names on a computer system to be shared between multiple LAN adapters. A processor, under the control of the process, prompts a user for entry of a new adapter name. The adapter name is used to build a name query which is transmitted to a local area network (LAN) to determine if the adapter name is already in use by the same computer. If the adapter name is in use by the same computer, then the new adapter is linked to the existing adapter with the same name. However, if no response is received after an appropriate number of retry attempts, then the name is added to the local table of LAN adapter names. When the computer receives traffic addressed to a shared name, the process ensures that only one adapter at a time responds. The responsibility for responding to this traffic is transferred to all adapters sharing this name.

Abstract: A 3D scientific visualization system for viewing models composed of polyhedra or other elements having vertices at which analysis results (e.g., temperature or pressure) are defined. The model is viewed either in a cutting plane or as a contour surface in which a given result assumes a specified value. Polygons making up an intersection surface formed by the intersection of the cutting plane or contour surface with the polyhedra forming the model are generated and passed to a polygon processor for rendering and display on a raster-scan device. A series of intersection surfaces are generated for display by varying either the position of the cutting plane along its normal or the value that the result assumes on the contour surface.

Abstract: This invention permits an optimizing compiler to minimize the effect of pipeline delays, which are typically introduced by branching code. This invention employs code hoisting to introduce computations from lower regions of the flowgraph, into regions where pipeline delays are known to occur.

Abstract: A method, system and process for providing an improved database blocking technique for updatable and scrollable cursors is disclosed. The invention is facilitated by the operation of a process in the memory of a processor. The processor, under the control of the process, builds a reserved area in the memory of the computer. The reserved area in the memory contains an image of a portion of the information residing on disk in the database. When an application opens a cursor to a database, the type of blocking is specified for that cursor. The application issues a fetch request, and if the row is not in the block in the reserved area in the memory, then a remote procedure call is performed to get the required next block of rows and return the block containing the rows back to the application. Various lock data structures are employed to manage and control the processing.

Abstract: A method, system and program for efficiently archiving and recovering a database is disclosed. The archiving process utilizes a reverse chronological order for the tape to facilitate efficient restoration of the database. The recovery processing utilizes a linked list to track record updates and avoid updating the same record with anything but the most current information.

Abstract: In a computer graphics system, a method and apparatus for scaling a line pattern having a predetermined first number of pixels to an actual line having a predetermined second number of pixels different from said first number. The total line length is divided by the line pattern length to obtain the number of line pattern repetitions and the number of remainder pixels in the actual line per line pattern repetition. An error term is incremented by the number of remainder pixels per repetition for each pixel of a given line pattern repetition that is processed. When the cumulative error term equals the line pattern length, the error term is decremented by the line pattern length and an extra pixel is generated. For lines that are shorter than the line pattern, a similar procedure is used except that when the cumulative error term equals the line pattern length, a pixel is deleted.

Abstract: A system and method for preventing deadlock in a multiprocessor computer system executing instructions requiring multiple resources. The system detects potential deadlock situations where a multi-resource instruction is blocked from obtaining one of the resources. A multi-resource instruction global lock is provided that can be held by at most one processor. Upon conflict detection, the processor attempts to acquire the multi-resource instruction global lock and, if successful, resumes resource acquisition. The use of a global lock serializes multiple resource requests and assures that the processor holding the lock can eventually acquire all required resources without deadlock with another processor. The preferred embodiment acquires the global lock on an exception basis to minimize the overhead impact. However, an alternate embodiment which uses the global lock in each multiple resource instruction could also be implemented.

Abstract: A system and method for maintaining data coherency in a system in which data is replicated on two or more servers. Each server is able to update the data replica present on the server. Updates are logged for each server. Reconciliation of server data replicas is aggressively initiated upon the occurrence of predefined events. These events include arrival at a scheduled time, a request for data by a client system, server and network failure recovery. Reconciliation is managed by a coordinator server selected to ensure that at most one coordinator server per network partition is selected. Logged updates are merged and transmitted to each server containing a data replica. The logged updates are applied unless a conflict is detected. Conflicts are collected and distributed for resolution. Reconciliation is managed between servers without regard to operating system or physical file system type.

Abstract: A system and method for providing a data processing system operable for displaying anti-aliased lines on a display device comprised of a matrix array of pixels. This system receives data pertaining to the line to be displayed, the line being defined by start and end points which position the line relative to the pixels within the matrix array. The relative position of the line with respect to pairs of pixels bounding the line are ascertained. The illumination intensities for each pixel within each pair is then dependent upon this relative position. The relative positions are ascertained by subdividing the matrix array of pixels into subpixel regions so that the subpixel nearest the intersection of the line and a theoretical boundary intersecting the pairs of pixels may be established.

Abstract: A method and apparatus for the management of the data associated with multiple graphics contexts in a computer graphics rendering system. Graphics contexts are built by graphics engines and selectively saved into a context save RAM. Context switches are managed either by modifying a context base pointer to address a new section of the context save RAM, or by writing out a portion of the context save RAM to external storage and reading in a replacement context from external storage. The writing and reading process are managed by a control processor allowing the graphics engines to switch context at the same time. New contexts read from external storage automatically cause regeneration of downstream rasterization parameters.

Abstract: A method, system and program for redefining language dependent object definitions as a neutral set of information from which object support for any language, including support between languages, is disclosed. The information is parsed and compiled to generate a bindings file which is input along with method information to the target language compiler to create an object file. The object file is thereafter link edited to create executable programs. Target languages include C, Fortran, C++, COBOL or any other compiled language whether or not the particular language has object programming support. Messages are displayed on a display to aid a user.

Abstract: Apparatus and process for managing shared, distributed locks in a multiprocessing complex. The manager operates using a partitionable lock space with logical processor connection. Logically connected processors are subject to validation and disconnection due to failure. The locks synchronize data access to identifiable subunits of DASD. Denied lock requests are queued for servicing when the lock becomes available. Lock partitions are used to speed DASD to DASD copying without halting processing on the first DASD. A special partition is assigned to the copy task and the processors writing to the DASD can determine copy status with a single read or test. Operations requiring multilateral agreement of processors, such as rebuilding locks or moving locks, are protected by fencing any nonresponsive processor. A special queue partition is designated for master/slave control point designation. All processors contend for the master lock and losing contenders are queue.

Abstract: A parallel vector generator in which an Nx .times.Ny array of processors, each assigned to one particular pixel of each Nx .times.Ny block of contiguous pixels, operate concurrently to generate a pixel image of a line. Each processor of the array executes a version of the Bresenham line-drawing procedure that is modified so that iterations for pixels over which the processor has no control is eliminated. The processors are capable of processing lines having subpixel endpoints while using only integer arithmetic. Each processor contains a pair of parallel vector generators that are used to generate the endpoints of a triangle along each scan line.

Abstract: A method, system and program for allowing an application designed to use static method calls to manipulate objects whose methods are only available through dynamic calls without modifying the binary image of the application. A SOM compiler generates class definitions and generates a redispatch stub for each method defined in a class. A redispatch stub is a short sequence of instructions with an identical calling sequence as its corresponding method. This gives the class' dispatch enough information to determine the correct method procedure in a dynamic manner. The dispatch function employs the redispatch stub to call the appropriate method procedure and return any return value to the calling application via the redispatch stub. Redispatch stubs allows a class with a definition that can vary at runtime to be used by an application that was designed for statically defined classes.

Abstract: A method, system and program providing graphical queries and direct manipulation of a database is disclosed. In a preferred form, tables and lists are configured from a database to define a common data structure. Additional, dynamic data structures are employed based on information entered by a user to define various relationships between the dynamic data and the database information. The system employs a graphical query interface and a relational database to provide an ergonomic, natural interface for a database user.