RSS Feeds and Comments

I haven’t been using RSS feeds myself up to now, and I assumed they were just available for those who did, but it seems you have to activate them, so I have done that and you can now click on the buttons on the right which connect to:

https://newtonexcelbach.wordpress.com/feed/

https://newtonexcelbach.wordpress.com/comments/feed/

Also I’d encourage readers to post comments with questions, suggestions, and additional information.  It’s the comments as much as the content that makes sites like Daily Dose of Excel such a valuable resource, and as the traffic here increases I hope we can develop an equally worthwhile dialog.

Look forward to hearing from you 🙂

Posted in Computing - general | Tagged , | 4 Comments

Tanh-Sinh Quadrature Update 2

I have copied the latest version of Graeme Dennes’ Tanh-Sinh Quadrature spreadsheet to my download site:  Click here to download Tanh-Sinh.zip

As before, the download includes full open-source code, and detailed notes by Graeme.

In the new version the Gauss-Kronrod function has been modified to give similar precision to the Tanh-Sinh function.  The result is that on a like for like basis the Tanh-Sinh function now averages 40 times faster than the Gauss-Kronrod function, and in one case it is about 750 times faster!

The screen-shots below show the recalc times and cumulative errors for integration of 55 different functions, using the three different integration methods.  I recommend this spreadsheet to anyone looking for an efficient high precision numerical integration method.

Tanh-Sinh Function; click to view full size

Gauss-Kronrod Function

Romberg Function

Posted in Excel, Maths, Newton, Numerical integration, UDFs, VBA | Tagged , , , , , , , | 4 Comments

The structural analysis of domes: From Pantheon until Reichstag

An interesting paper with technical details of several historical domed structures, available for free download, from Dokuz Eylul University, Izmir, Turkey:
The structural analysis of domes

Posted in Arch structures, Newton | Tagged | 1 Comment

Getting hard disk physical serial numbers

There was a question at Eng-Tips about how to get the physical serial number of a hard disk (rather than the soft number, that is changed by a re-format): http://eng-tips.com/viewthread.cfm?qid=285948&page=1

A search found this discussion with the answer: http://thedailyreviewer.com/office/view/programmatically-obtain-the-hard-disks-serial-number-from-vba-101853101
(see answer number 8 )

from which I wrote the following code for an Excel User Defined Function (UDF) that will return the physical serial number of all the hard disks connected to the computer it is running on (enter as an array function to display data for more than one disk):

Function GetPhysicalSerial() As Variant

Dim obj As Object
Dim WMI As Object
Dim SNList() As String, i As Long, Count As Long

Set WMI = GetObject("WinMgmts:")

For Each obj In WMI.InstancesOf("Win32_PhysicalMedia")
If obj.SerialNumber <> "" Then
Count = Count + 1
Next

ReDim SNList(1 To Count, 1 To 1)

i = 1
For Each obj In WMI.InstancesOf("Win32_PhysicalMedia")
SNList(i, 1) = obj.SerialNumber
i = i + 1
If i > Count Then
 Exit For
Next

GetPhysicalSerial = SNList
End Function

References required for the function to work are shown in the screen shot below:

References for WinMgMts Object

I haven’t used the WinMgmts object before, but it seems that it will return a wide variety of other information about your hardware, although the usage is not particularly user-friendly.  The best source of information I could find was:

http://msdn.microsoft.com/en-us/library/aa394585

Posted in Excel, UDFs, VBA | Tagged , , , , | 1 Comment

coffeescup a.k.a. lemonflower

Browsing for anything new on You Tube I come across a cover of Anne Briggs’ “Go Your Way”.  Typical You Tube home produced standard, jerky out of sync video, dim lighting, adjust the controls before the song starts, yawn … then she starts singing.

4 minutes 30 seconds later I’m a convert.  Someone says she has a nice voice; she has a nice voice like Shakespeare had a bit of a way with words.  She makes this Anne Briggs song her own, and I can think of no higher praise.  Have a listen:

Posted in Bach | Tagged , , | 20 Comments