### Categories

### RSS Feed

### Search NewtonExcelBach

### Archives

### Top Posts

- Commenting a block of code in VBA
- Solving Quadratic, Cubic, Quartic and higher order equations; examples
- Using Goal Seek on Multiple Cells
- Downloads by category
- The angle between two vectors, Python version
- Using LINEST for non-linear curve fitting
- Fitting high order polynomials
- Cubic Splines
- Open Source FEA Code Links
- The angle between two vectors, in 2D or 3D

### Recent Comments

Numerical Integratio… on Numerical integration with on-… josh on Import Data from a Picture to… Melanie Safka + Mile… on Melanie Safka Mohd Yousef on Biaxial bending update DonB on Biaxial bending update Mohd Yousef on Biaxial bending update dougaj4 on Biaxial bending update DonB on Biaxial bending update dougaj4 on Biaxial bending update DonB on Biaxial bending update Mohd Yousef on Biaxial bending update dougaj4 on Beam Fixed End Actions by Maca… Peka Odendaal (@PKOd… on Beam Fixed End Actions by Maca… Gerardo Freyre on The history of the theory of b… dougaj4 on Time in hours and minutes betw…

# Category Archives: Differential Equations

## xlwSciPy update for Python 3

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 Excel, Numpy, Python, SciPy, UDF, VBA, xlwings
2 Comments

## Rabbits, Foxes, and Lorenz Attractors

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 AlgLib, Excel, Lorenz Attractor, Predator-Prey, Solution of ODEs, Systems of ODEs, UDF, VBA, XNumbers
2 Comments

## Daily Download 21: Assorted Solvers

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

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

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 big numbers, Excel, hole through the middle of the earth, ODE Function, Perfect gas, UDF, VBA
4 Comments

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

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 Excel, hole trough the middle of the Earth, ODE Function, ODE solver, UDF, VBA
2 Comments