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Category Archives: Maths
Brent’s Method; Update and Examples
Brent’s Method is a refinement of Newton’s Method for the numerical solution of any equation with one variable. The User Defined Function (UDF) QuadBrent was described in: The Inverse Quadratic Method 3 – Brent’s Method Following a recent question, I have … Continue reading
Posted in Arrays, Excel, Maths, Newton, UDFs, VBA
Tagged Brents method, Excel, inverse quadratic, iterative solution, Maths, UDF, VBA
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Update to AL-Spline-Matrix
The AL-Spline-Matrix spreadsheet contains a large number of VBA user defined functions (UDFs) performing spline fitting and matrix operations, using the free and open source ALGLIB library. It was recently pointed out that the Excel interface code for the CSplineFitCW1da … Continue reading
Posted in AlgLib, Excel, Maths, Newton, UDFs, VBA
Tagged AlgLib, Cubic spline, Excel, spline curve fitting, UDF, VBA, weights and constraints
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Hofstadter, Pahud, Bach
The latest ACO concert series features the Swiss flautist Emmanuel Pahud (interview here). The performance included J.S. Bach’s 6 Part Ricercar, from The Musical Offering, which was the inspiration for the final dialogue in Douglas Hofstadter’s Godel, Esher, Bach: Achilles … Continue reading
Posted in Bach, Maths, Newton
Tagged AC0, Bach, Douglas Hofstadter, Emmanuel Pahud, Godel Escher Bach, Ricercar a 6
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Working with implied units – update
Following comments at Eng-Tips I have added two examples with different procedures for evaluating ACI equations for the flexural tensile strength of concrete here.
Posted in Excel, Maths, Newton, UDFs, VBA
Tagged ACI 318, Customary US Units, Eval, EvalU, Evaluate text, Excel, Implied units, shear capacity, SI Units, UDF, Units aware, Units4Excel, VBA
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Using Alglib least-squares solvers
Following the last post on using the Python version of Alglib from Excel, via xlwings, this post looks in more detail at alternatives for fitting a non-linear function to a set of data, using the Levenberg-Marquardt method. The spreadsheet with … Continue reading
Posted in AlgLib, Curve fitting, Excel, Link to Python, Maths, Newton, NumPy and SciPy, UDFs, VBA, xlwings
Tagged AlgLib, Excel, Levenberg Marquardt, lsfit, minlm, Numpy, Python, SciPy, UDF, VBA, xlwings
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