Abstract: A computer program product determines elementary circuits and initial values of flows in a pipe network including one or more source nodes and a plurality of demanding nodes. An upstream node and a downstream node of each pipe is determined. The upstream node has less total resistance than the downstream node to the source nodes. A pipe joined between an upstream node and a downstream node is selected as an upstream pipe of the downstream node. A pipe which is never designated as an upstream pipe is selected as a circuit origin pipe. A node level, which indicates the number of nodes included in the passage from the source node, is determined. An elementary circuit is determined, by tracing upstream nodes along a first route starting from a first node of the circuit origin pipe and along a second route starting from a second node of the circuit origin pipe in accordance with the node level of the upstream node of each pipe, until the first and second routes reach a same source node or a same demanding node.

Abstract: A computer program product for searching line data to be transmitted to a terminal which demands an output map. The line data is obtained by selecting line segments within an output domain from the entire line data included in an object map read from a graphic file. The selection of the line segments is performed by obtaining the coordinates of intersections of lines specifying the output domain and line segment specified by any two adjacent characteristic points on a line associated with line data read out from the graphic file, and then by arranging the intersections and the characteristic points within the output domain sequentially along the line. This makes it possible to shorten the response time between a demand from the terminal and the actual output of the line data within the output domain to that terminal.

Abstract: A method for searching line data to be transmitted to a terminal which demands an output map. The line data is obtained by selecting line segments within an output domain from the entire line data included in an object map read from a graphic file. The selection of the line segments is performed by obtaining the coordinates of intersections of lines specifying the output domain and line segment specified by any two adjacent characteristic points on a line associated with line data read out from the graphic file, and then by arranging the intersections and the characteristic points within the output domain sequentially along the line. This makes it possible to shorten the response time between a demand from the terminal and the actual output of the line data within the output domain to that terminal.

Abstract: A graphic editing system and method uses a terminal for editing line graphic data stored in a host computer. The graphic data of a drawing to be edited is retrieved from a common file and is loaded onto the host computer's work area. The graphic data is then loaded onto the terminal's memory and displayed on the terminal. A line of the drawing to be edited is selected on the terminal. The line to be edited is then searched in the host computer's work area and stored in the host computer's edit area, where it is edited. The edited line is then loaded into the terminal's memory from the edit area and displayed on the terminal.

Abstract: A method for determining elementary circuits and initial values of flows in a pipe network including one or more source nodes and a plurality of demanding nodes. An upstream node and a downstream node of each pipe is determined. The upstream node has less total resistance than the downstream node to the source node. A pipe joined between an upstream node and a downstream node is selected as an upstream pipe of the downstream node. A pipe which is never designated as an upstream pipe is selected as a circuit origin pipe. A node level, which indicates the number of nodes included in the passage from the source node, is determined. An elementary circuit is determined, by tracing upstream nodes along a first route starting from a first node of the circuit origin pipe and along a second route starting from a second node of the circuit origin pipe in accordance with the node level of the upstream node of each pipe, until the first and second routes reach a same source node or a same demanding node.