Eric Leslie Vogel

US Patent:

51757001, Dec 29, 1992

Filed:

Jan 25, 1991

Appl. No.:

7/645953

Inventors:

Eric L. Vogel - Corvallis OR
Chris M. Bunsen - Corvallis OR

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G06F 300

US Classification:

36471011

Abstract:

In a calculating device, a method and apparatus for representing to a user the state of variables in multiple equations to be solved. The representation in the present embodiment is through a user interface. The interface displays labels assigned to the variables within the multiple equations and indicates to the user on the label the state of each variable. These states are four: user-supplied values (U); calculator-supplied values (C); related values (R); and non-related values (N). Related values (R) are values that were used or solved for together in the latest solution of the equations. Through menu keys assigned to the variables represented by the labels, a user can supply or clear values for the variables for the next solution. The method also includes saving the order in which the variables are found and the order in which the equations are solved. This information allows the user to review the solution path followed by the calculating device in solving the multiple equations.

US Patent:

52166279, Jun 1, 1993

Filed:

Jan 25, 1991

Appl. No.:

7/645860

Inventors:

Paul J. McClellan - Corvallis OR
Eric L. Vogel - Corvallis OR
William C. Wickes - Corvallis OR

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G06F 100
G06F 738

US Classification:

364700

Abstract:

A method for performing unit conversion and managing units in mathematical computations. The method employs unit objects, which each have a scalar part and a unit part that together are treated as a single entity in computation. In the process of carrying out computations, the unit object operands of a particular operation are disassembled into their scalar and unit parts, new scalar and unit parts are calculated therefrom, and the new parts are combined to produce the new unit object. The method thereby simplifies computation involving physical quantities such as length and temperature and also aids in verifying that the computations are correct. To simplify the entry of the unit parts for unit objects, a unique user interface is provided.