Category Archives: Arrays

Transfer of arrays to/from Python with Pyxll – Part1; Data Types

Posted on 16/03/2014 by dougaj4

This post will look at options for transferring arrays between Excel and Python using Pyxll, including data types, and problems associated with transferring mixed data types.  In the following post I will look at the relative performance of the various … Continue reading →

Posted in Arrays, Excel, Link to Python, VBA | Tagged , , , , | 2 Comments

The speed of loops in Python

Posted on 24/01/2014 by dougaj4

This post is based on exercises published by Cyrille Rossant in his book “Learning IPython for Interactive Computing and Data Visualization”.  Cyril also has a blog well worth looking at: http://cyrille.rossant.net/blog/ (Thanks to Alfred Vachris and Boris Vishnevsky for the links). … Continue reading →

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Two MaxAbs functions

Posted on 20/01/2014 by dougaj4

Excel does not have a built-in function to find the maximum absolute value of a range, perhaps because the Max() and Abs() functions can be combined in an array function: =Max(Abs(datarange)) This solution has a number of drawbacks however: The … Continue reading →

Posted in Arrays, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , | 9 Comments

Solving Quadratic, Cubic, Quartic and higher order equations; examples

Posted on 14/01/2014 by dougaj4

A previous post presented a spreadsheet with functions for solving cubic and quartic equations, and this has been extended with another function solving higher order polynomials.  The functions are actually very easy to use, but the documentation in the spreadsheets is quite brief, … Continue reading →

Posted in Arrays, Excel, Link to Python, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , , | 13 Comments

Python for VBA users- 7; Making Python go Faster

Posted on 20/12/2013 by dougaj4

As reported in the previous post in this series, although the compiled routines included in packages such as Numpy, Scipy, and Pysparse are very fast, other parts of the code turned out to be slower than the equivalent in VBA.  … Continue reading →

Posted in Arrays, Excel, Finite Element Analysis, Frame Analysis, Link to Python, Newton, NumPy and SciPy, UDFs, VBA | Tagged , , , , , | Leave a comment