Tag Archives: AlgLib

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

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Evaluating text and calling Python functions from Excel with xlwings

The Alglib spreadsheet presented here includes functions to evaluate formulas entered as text on the spreadsheet, or to call specified Python functions.  I have now added a user defined function (UDF) that will perform either of these operations (xl_CallFuncD), and added … Continue reading

Posted in AlgLib, Excel, Link to Python, Maths, Newton, NumPy and SciPy, UDFs, VBA, xlwings | Tagged , , , , , , , , , | 1 Comment

Excel to Alglib via xlwings

The Alglib library provides many valuable numerical analysis routines, but the VBA version is no longer actively maintained.  The latest versions are available in C++, C#, and Python, of which the Python version (in conjunction with xlwings) provides the easiest interface … Continue reading

Posted in AlgLib, Curve fitting, Excel, Link to Python, Maths, Newton, Numerical integration, UDFs, VBA, xlwings | Tagged , , , , , , , , , | 3 Comments

Weighted Least Squares Regression, using Excel, VBA, Alglib and Python

Least squares linear regression in Excel is easy.  That’s what the Linest and Trend functions do.  That is, they find the coefficients of a straight line (or higher dimension shape) so that the sum of the squares of the distances of … Continue reading

Posted in AlgLib, Curve fitting, Excel, Link to Python, Maths, Newton, NumPy and SciPy, UDFs, VBA | Tagged , , , , , , | 3 Comments

ExcelPython2, Alglib and Spline-Matrix Rel 2.03

Following a comment here: ExcelPython2, Alglib and Spline-Matrix update I have updated the VBA and Python code, and added a missing Python module to the download zip file.  See the earlier post for details of installation and use, or download the revised files … Continue reading

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ExcelPython2, Alglib and Spline-Matrix update

The ExcelPython add-in, offering easy access to Python code from Excel VBA, has had a major update to Release 2.  The new version provides new features and simpler installation, but has some incompatibilities with code written for the previous  version, so the … Continue reading

Posted in AlgLib, Excel, Link to Python, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , | 4 Comments

Alglib/Python spline functions update

The Excel Spline-Matrix spreadsheet has now been updated with several new spline interpolation functions.  See Alglib/Python linear and non-linear fitting functions for links to download and install the necessary Excel-Python and Alglib files.  Also required is Python version 2.7 or 2.6. The … Continue reading

Posted in AlgLib, Arrays, Excel, Link to Python, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , , , | 2 Comments