In this paper, we discuss some characteristic properties of partial abstract data type (PADT) and show the diffrence between PADT and abstract data type (ADT) in specification of programming language. Finally, we clar...In this paper, we discuss some characteristic properties of partial abstract data type (PADT) and show the diffrence between PADT and abstract data type (ADT) in specification of programming language. Finally, we clarify that PADT is necessary in programming language description.展开更多
Ada provides full capacities of supporting object orientation, but the diversified objects patterned in Ada are so intricate that Ada95's aim would be demolished. In order to complement the disfigurement that Ada...Ada provides full capacities of supporting object orientation, but the diversified objects patterned in Ada are so intricate that Ada95's aim would be demolished. In order to complement the disfigurement that Ada does lack for a pristine notion of class, this paper presents a remolded object pattern known as A object, an Ada based class description language A ObjAda aiming at support for A object pattern and the related approach for key algorithms and implementation. In consequent, A ObjAda hereby promotes Ada with highlighted object orientation, which not only effectively exploits the capacities in Ada95, but also rationally hides befuddling concepts from Ada95.展开更多
坐标转换是空间地理数据应用的常用功能,由于部门及应用场景不同,不同坐标系成果的相互转换工作将长期存在。目前的坐标转换不仅需要脱离ArcGIS和AutoCAD等软件,还要实现主流矢量数据和栅格数据的坐标转换。为此提出了基于GDAL(geospati...坐标转换是空间地理数据应用的常用功能,由于部门及应用场景不同,不同坐标系成果的相互转换工作将长期存在。目前的坐标转换不仅需要脱离ArcGIS和AutoCAD等软件,还要实现主流矢量数据和栅格数据的坐标转换。为此提出了基于GDAL(geospatial data abstraction library)和Teigha库底层开发的通用坐标转换方法,给出了系统架构,实现了参数管理、参数计算、坐标转换、数据读写等功能。该方法大大提高了转换效率和保密性。实践表明,该系统转换结果正确可靠。展开更多
基金The Project Supported by National Natural Science Foundation of China
文摘In this paper, we discuss some characteristic properties of partial abstract data type (PADT) and show the diffrence between PADT and abstract data type (ADT) in specification of programming language. Finally, we clarify that PADT is necessary in programming language description.
基金Supported by National Natural Science Foundation of China(6 97730 41)
文摘Ada provides full capacities of supporting object orientation, but the diversified objects patterned in Ada are so intricate that Ada95's aim would be demolished. In order to complement the disfigurement that Ada does lack for a pristine notion of class, this paper presents a remolded object pattern known as A object, an Ada based class description language A ObjAda aiming at support for A object pattern and the related approach for key algorithms and implementation. In consequent, A ObjAda hereby promotes Ada with highlighted object orientation, which not only effectively exploits the capacities in Ada95, but also rationally hides befuddling concepts from Ada95.
文摘坐标转换是空间地理数据应用的常用功能,由于部门及应用场景不同,不同坐标系成果的相互转换工作将长期存在。目前的坐标转换不仅需要脱离ArcGIS和AutoCAD等软件,还要实现主流矢量数据和栅格数据的坐标转换。为此提出了基于GDAL(geospatial data abstraction library)和Teigha库底层开发的通用坐标转换方法,给出了系统架构,实现了参数管理、参数计算、坐标转换、数据读写等功能。该方法大大提高了转换效率和保密性。实践表明,该系统转换结果正确可靠。
