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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
Posted in Excel, Maths, Newton, UDFs, VBA
Tagged Excel, iterative solution, Lagrangian point, Newton, polynomial solution, UDFs, VBA
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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
Posted in Charts, Excel, Maths, Newton, Numerical integration, UDFs, VBA
Tagged Double Exponential, Excel, Gauss-Kronrod, numerical integration, Romberg, Tanh-Sinh method, Tanh-Sinh Quadrature, UDF, VBA
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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 Excel, multiple integration, Python, PyXLL, SciPy, UDFs
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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
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 evaluate pi, Excel, high precision maths, mpmath, Python, PyXLL, UDFs, VBA, xlwings
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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 arcspline, Array function entry, Automatic re-size array functions, Excel, IP2.xlsb, Line intersections, UDFs, VBA
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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 Double Exponential, Excel, Gauss-Kronrod, numerical integration, Romberg, Tanh-Sinh method, Tanh-Sinh Quadrature, UDF, VBA
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