Category Archives: Link to Python

Alglib/Python spline functions

Posted on 25/07/2014 by dougaj4

Continuing from the previous post, the new xl_Spline-Matrix.zip spreadsheet includes functions for 1D and 2D linear and cubic splines. The basic 1D spline allows  for output of linear splines, or 5 different types of cubic spline, as listed above. Output may … Continue reading →

Posted in AlgLib, Excel, Link to Python, Maths, Newton, Numerical integration, UDFs, VBA | Tagged , , , , , , , , , , , | 1 Comment

Alglib/Python linear and non-linear fitting functions

Posted on 23/07/2014 by dougaj4

I have updated the Alglib spline-matrix spreadsheet to use the latest Alglib release, using the Python version, in conjunction with the Excel-Python add-in. To use the spreadsheet requires: Python ver 2.7 (or 2.6) Excel-Python Alglib with Python interface In addition … Continue reading →

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

Evaluating text and Integration with Python and ALGLIB

Posted on 07/07/2014 by dougaj4

Following the previous post on evaluating mathematical functions entered as text on the spreadsheet, I have now written a spreadsheet with similar functionality using Python functions, and the Excel-Python add-in.  Also included are integration functions using the SciPy Python library, … Continue reading →

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

Data Transfer to Python – Update

Posted on 08/06/2014 by dougaj4

As noted in the comments here, the main bottleneck in the Python matrix solver functions presented recently was not in the data transfer from Excel, but rather in the creation of the Numpy arrays for very long lists of short … Continue reading →

Posted in Arrays, Excel, Frame Analysis, Link to Python, NumPy and SciPy, VBA | Tagged , , , , , | 4 Comments

Two Timers

Posted on 06/06/2014 by dougaj4

The simplest way to check the execution time of VBA code is with the built in Timer function, but this returns a single precision value in seconds, resulting in a minimum time step of about 10 milliseconds.  For VBA code … Continue reading →

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