Showing papers in "Computers & Geosciences in 1976"

TL;DR: In this paper, a grid of values that approaches the smoothest surface passing through the control points is generated, and a grid can be automatically contoured automatically by standard routines, producing acceptable results.

TL;DR: The computer program CABFAC for Q-mode factor analysis of geologic data has been extended for use with data having constant row-sums, and two programs serve to reproduce estimates of the original data rather than of the data in normalized form.

TL;DR: In this paper, an extended form of the method of Q-mode factor analysis is used if the rows of the data matrix sum to a constant, which provides a means for scaling the factor model to conform to the units of the original data in such forms as proportions, percentages, or parts per million.

TL;DR: A brief resume of the properties, uses and potentialities of auxiliary functions, followed by some computer FUNCTIONs in the FORTRAN IV language for their evaluation for the spherical or ‘Matheron’ model of the semivariogram.

TL;DR: An extended form of Q-mode factor analysis may be used if the row-sums of the data matrix are constant and can be helpful especially in developing and testing petrologic-mixing models for igneous systems.

TL;DR: Modifications to the earlier model of Bridge (1976) are described using the original section headings using a new FORTRAN IV listing with full commentary, along with revised input requirements, and an example of the new line-printer output.

TL;DR: The PETROS data bank as mentioned in this paper is a fixed-format magnetic tape data bank of major-element chemical analyses of igneous rocks divided into groups representing selected geographic areas and petrologic provinces.

TL;DR: The system provides for data storage, retrieval, analysis, and display together with utility software to handle data-base maintainance and the integration of processes, the diversity of data-handling capability, and the user-friendly commands are the key design features.

TL;DR: Two algorithms are presented for the rapid and exact computation of the area within a closed polygonal boundary, and for determining the coordinates of the center of mass of that area by a Stokes' Theorem transformation.

TL;DR: TOPO III as discussed by the authors is a FORTRAN program that operates with rectangular arrays of equally spaced elevations, producing lists of terrain parameters (coordinates, elevation, average, maximum relief, average and maximum slope, azimuth of maximum slope and topographic shape: slope, ridge, valley, knob, sink, saddle).

TL;DR: With this model the effects of thin section can be investigated for any fabric of prolate rotational ellipsoids and the recursion algorithm will only be used under the assumption of spherical grains.

TL;DR: An algorithm and FORTRAN IV computer program SELLO for obtaining univariate nonskewed distributed data from skewed raw data is presented and chemical data from 566 rock specimens collected during 1972 in Sweden were examined.

TL;DR: A FORTRAN IV program that calculates the area of influence of drill holes or samples with respect to the size and shape of elliptical or circular resource targets is presented.

TL;DR: A difficulty associated with the fitting of a sample data set to a von Mises distribution is drawn and FORTRAN IV subroutines to overcome this are presented.

TL;DR: Real arrays of order NORD × NDATA as mentioned in this paper are used to determine the total and mean square successive difference covariance matrices, they are destroyed by CANON, but if NOCUT CANON is modified suitably, may be returned.

TL;DR: An algorithm is developed for making magnetic field “reduction-to-the-pole” computations using two-dimensional Fourier series using a “look-up table” to reduce the number of trigonometric functions to be evaluated.

TL;DR: The program described here computes diversity indices and related statistics of the total collection and of a randomly selected subset of size determined by the user, and one subroutine, DIVERS, is used in the computation of diversity and equitability.

TL;DR: A suite of FORTRAN IV programs (LEAP—Land Erosion Analysis Programs) has been developed which evaluates the interaction between these variables to produce three-dimensional plots of erosion potentials.

TL;DR: A new model for a scientific data bank applicable to geological data, composed of four concentric rings, which establishes a base for geological simulation and modeling and shows potential for a wide application in the natural sciences.

TL;DR: A relatively simple computer data-bank system including only the most important data fields and designed to supplement rather than replace conventional records is judged to provide an optimal return for the staff effort available.

TL;DR: A FORTRAN IV program is presented that computes apparent resistivity of a perfectly conducting sphere buried in a half-space at any depth and for any electrode configuration.

TL;DR: A general-purpose computer program implementing Williams and Lambert's method of association analysis is documented, which embodies a hierarchical-divisive-monothetic strategy for the numerical classification of multiattribute, binary-coded data sets.

TL;DR: In this article, the Fourier transform is used to produce a circular plot of relative frequencies of light intensity recorded digitally over all directions on the transform plane by a set of photodiodes, normalized and circularly plotted by computer to produce optical rose diagrams.

TL;DR: The G-EXEC System represents a partial implementation of a “geological computer” which consists of a relational data base, highly structured processing software designed to reflect geological thinking and input/output interface software to aid a user of the system.

TL;DR: A distributed system under development by the Surveys and Mapping Branch of the Department of Energy, Mines and Resources in Canada, for the production of faired drawings from a geographic data base is referenced.

TL;DR: In this paper, a new technique for structural analysis of dip-strike data is described, from which a dip strike distribution map, structure contour map, and block diagram are automatically prepared on an X-Y plotter by using four computer programs.

TL;DR: Computer-assisted instruction is being used successfully, albeit limited, in several fields of geology and will have increasing application as geology students are introduced to quantitative methods and computers earlier in their education.