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Messages - MalcolmHLevitt

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Bug reports / Re: Bug - Transformation Amplitude Table (SDv.15.1b7).
« on: October 03, 2016, 01:21:32 PM »
Thanks Stuart,

bug report noted. I'm on the case.


Hi Andy,
 while introducing SD v2.14.3, which is compatible with Mathematica 11, I also located and fixed this problem.
all the best

Bug reports / Re: Mathematica 11
« on: August 16, 2016, 05:07:46 PM »
The latest release 2.14.3 is now compatible with Mathematica 11.

However, the SpinDynamica symbol Duration conflicts with the newly introduced Mathematica 11 symbol of the same name, and has been replaced by EventDuration.

SpinDynamica 2.14.3 has been released.

This version is compatible with Mathematica 11.

Note that the SpinDynamica symbol Duration clashes with the Mathematica 11 symbol of the same name and has been superseded by EventDuration

Download here:

Bug reports / Mathematica 11
« on: August 15, 2016, 04:14:49 PM »
The latest release of SpinDynamica (2.14.2) does not yet run under the newly-released Mathematica 11. This is because Wolfram have introduced a new built-in symbol Duration which conflicts with its prior definition under SpinDynamica. A Mathematica11 workaround will be released shortly.


Examples / 2D spectroscopy
« on: July 28, 2016, 02:05:40 PM »
Although SpinDynamica does not yet contain a fully general routine for 2D spectral simulation, the attached notebook allows the calculation of 2D spectra in some useful special cases. Code of this kind will be included in SpinDynamica itself, in future releases.

As usual the graphics have been stripped out but will be regenerated upon running the notebook.


Since I was using a slightly older version of Mathematica (10.3) I decided to update to 10.4 and try again.

This time I got the same behaviour as you!

So there is a subtle difference between Mathematica 10.3 and 10.4 which causes different behaviour for this particular calculation, which is very unexpected. I hope to debug this after my summer break.

There should be no need for you to send me the files I requested in the previous post.

all the best

Thanks Andy,
 this is very puzzling. Which version of Mathematica do you have?

 Can you run the attached file on your system including the Trace instructions and send the result back. If its too large to attach here please put it on dropbox and send me the link, or some other way. I want to see the complete file, not just screen clips.

 please start from a completely clean kernel and simply add a $Path instruction before Needs, if you need to do that.

 I will be away for a while now but I will look at this in the course of time. I havent seen a case where the same code gives different results when running the same version of Mathematica and SpinDynamica on separate systems.


Hi Andy, thanks for posting - I just checked the forum and picked up on your problem.

This puzzles me since when I add the line Needs["SpinDynamica`"] to the top of your file and run it, starting from a clean kernel, I do not get the behaviour you describe (see attached file). One possibility is that you were trying out some of the features in the documentation, such as the setting for $Chronology (end of part 1) and that a setting was thereby changed. Mathematica has the feature that anything you do in a session persists for the rest of the session, so maybe that is the problem.

Please retry, starting from a clean kernel (i.e. restart the kernel) and using the Needs line above to load SpinDynamica. Let me know how it goes.

All the best

Publications / Re: Spatial Frequency Encoding NMR
« on: July 26, 2016, 04:44:20 PM »
thanks for posting!

ps. any chance of posting the notebook on this forum as an attachment (perhaps with graphics stripped out to save space)?

Examples / Re: Chemical exchange in an AB system
« on: July 18, 2016, 01:44:18 PM »
Hi Andy,
 thanks for this. Just as for the AB case I posted, handling chemical exchange (as required for CPMG on a chemically exchanging system) entirely within SpinDynamica is currently not possible, although the necessary package extension is thoroughly feasible and the necessary functionality has long been planned. The problem is time and manpower. The existence of a strong demand is a very good stimulus but I am simply too busy to promise it in a short timeframe. If anyone is out there who feels sufficiently motivated to take on a programming task of this kind, I am very willing to help them.
 So although a general implementation of multisite chemical exchange in SpinDynamica is still some way off, programming a task-specific piece of code (as I did for the AB example) is more feasible. However, once again, my lack of time makes it hard to do this without additional help.
 sorry for this discouraging news

Updates and Messages / Add-Ons
« on: March 18, 2016, 03:06:47 PM »
Two add-on packages have been posted on the SpinDynamica website

SymmetryBasedRecouplingAnalysis is a resurrection of the old routines CandRsymmetries which allows calculation of selection rules and scaling factors for symmetry-based recoupling sequences.

PolarizationOperator is a new symbol which may be used to derive the level of polarization of a single spin or set of spins, from an arbitrary density operator.

Updates and Messages / SpinDynamica 2.14.2 released
« on: February 07, 2016, 09:50:47 AM »
SpinDynamica 2.14.2 has been released here:

It includes some important bug fixes.

Examples / Re: Product operator calculations
« on: December 21, 2015, 10:40:41 PM »
Hi Jean-Nicolas,
 The timing issues you raise should have been addressed in v2.14.1

Publications / Quantum-rotor-induced polarization
« on: December 20, 2015, 01:07:55 PM »
The paper

S.S. Roy, J.-N. Dumez, G. Stevanato, B. Meier, J.T. Hill-Cousins, R.C.D. Brown, et al., Enhancement of quantum rotor NMR signals by frequency-selective pulses, J. Magn. Reson. 250 (2015) 25–28. doi:10.1016/j.jmr.2014.11.004.

uses SpinDynamica to treat quantum-rotor-induced polarization and predict enhancements generated by frequency-selective pulses.

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