Category Archives: Maths

Solving the Lagrangian Point equation for the Moon

This post was prompted by a recent question at Fitting high order polynomials, asking for Excel methods to solve the equations for the radius of the Moon’s Lagrangian Point 1. All the methods described in this post have been added to … Continue reading

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Numerical Integration; Tanh-Sinh Quadrature v. 4.42

Back to Newton and Excel. I recently received a new update to the Tanh-Sinh Quadrature spreadsheet from Graeme Dennes, which may be downloaded from: Tanh_Sinh Quadrature. From the Readme: The Tanh-Sinh quadrature workbook has been enhanced as follows: The Tanh-Sinh … Continue reading

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Multiple Integration with Scipy

Scipy has 3 functions for multiple numerical integration in the scipy.integrate module: dblquad: Compute a double integral. tplquad: Compute a triple integral’ nquad: Integration over multiple variables. I have written six functions to call these functions from Excel, via Pyxll: Each … Continue reading

Posted in Excel, Link to Python, Maths, Newton, Numerical integration, NumPy and SciPy, PyXLL, UDFs | Tagged , , , , , | 6 Comments

Another (very slow) way of computing pi

The previous post included 100 Python code one-liners for calculating pi that recalculates in a fraction of a second.  The video below shows an alternative approach that is a little slower: How much slower?  If you had a computer that would … Continue reading

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mpmath for Excel

mpmath has been mentioned in passing here before, but not in any detail.  The mpmath site says: mpmath is a free (BSD licensed) Python library for real and complex floating-point arithmetic with arbitrary precision. It has been developed by Fredrik … Continue reading

Posted in Excel, Link to Python, Maths, PyXLL, UDFs, VBA, xlwings | Tagged , , , , , , , , | Leave a comment

More updates to ArcSpline and IP2

I have uploaded version 2.18 of the IP2 spreadsheet to: IP2.zip The new version includes updates to the IP, IP_4, and ArcSpline functions, as described below.  The download is free and includes full open-source code. The IP and IP_4 functions find … Continue reading

Posted in Arrays, Coordinate Geometry, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , | Leave a comment

Numerical Integration; Tanh-Sinh Quadrature v. 4.4

Update 27 Nov 2018: Version 4.41 now available from the link below, with minor modifications for compatibility with Excel 2007. I recently received a new version (4.4) of the numerical integration spreadsheet by Graeme Dennes which is now available for … Continue reading

Posted in Charts, Excel, Maths, Newton, Numerical integration, UDFs, VBA | Tagged , , , , , , , , | 9 Comments