Category Archives: Differential Equations

xlwSciPy update for Python 3

Posted on April 9, 2018 by dougaj4

The xlwSciPy spreadsheet allows a wide variety of the science and maths functions in the Python Numpy and Scipy libraries to be called directly from Excel.  The spreadsheet has now been updated for use with Python 3.  The spreadsheet and … Continue reading →

Posted in Coordinate Geometry, Differential Equations, Excel, Link to Python, Maths, Newton, Numerical integration, NumPy and SciPy, Python Pandas, UDFs, VBA, xlwings | Tagged , , , , , , | 2 Comments

Rabbits, Foxes, and Lorenz Attractors

Posted on February 23, 2014 by dougaj4

Following comments here and here I have added two examples to the ODE Solver spreadsheet showing use of the ODE function to solve systems of differential equations with two or more coupled equations. The new version (including full open source … Continue reading →

Posted in AlgLib, Differential Equations, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , | 2 Comments

Daily Download 21: Assorted Solvers

Posted on October 8, 2012 by dougaj4

Today’s download starts with some simple linear interpolation methods used to solve polynomial equations, leading on to more sophisticated methods using quadratic or inverse quadratic interpolation. Also included is a solver for differential equations using the Cash-Karp Method, which is … Continue reading →

Posted in AlgLib, Beam Bending, Differential Equations, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , , , | Leave a comment

The hole through the middle of the Earth – filled with air

Posted on August 13, 2010 by dougaj4

Three air molecules go into a hole,  Well, I say three; could have been four or five.  Could have been nine or ten, doesn’t matter. Could have been fifteen, twenty – fifty. Round it up. Hundred. Let’s go mad, eh … Continue reading →

Posted in AlgLib, Differential Equations, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , | 4 Comments

The hole through the middle of the Earth – moved to the Equator

Posted on August 2, 2010 by dougaj4

Previous posts in this series assumed that the hole went from pole to pole, and ignored such complications as tidal effects and wobbles of the axis of rotation.  In this post we will examine the effect of moving the hole … Continue reading →

Posted in Differential Equations, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , | 2 Comments