ahlers01

ZITAT(Kevin Payne @ Apr 21 2009, 09:33 AM) If you have a PDA, you might be interested in this nice emulation... I use it on my HP iPAQ, so I don't have to unlearn RPN...

ZITAT(Ben Zimmer @ Jan 3 2009, 05:37 AM) Hi, I use the services offered by http://www.origo.ethz.ch/, and I am so far very satisfied with it. The big pluses for me: - they also host closed source projects - the server location ETHZ (the 'European Harvard' Eidgenössiche Technische Hochschule Zürich) should be a very reliable one... - anf of course it's free You might want to give it y try. Franz

ZITAT(Ronnie @ Jan 30 2008, 08:49 PM) It will work with all pdfs, but of course only text will be converted. And don't expect that it converts all text correctly. Ligatures, e.g., are not converted AFAI remember. You've got to try it... -Franz

ZITAT(Ronnie @ Jan 30 2008, 06:27 PM) Yes, it can be done, but not in a straightforward way, AFAIK. When I did it some time ago, I used a (free) utility 'pdf2txt'. Google will show you where to find it. I called 'pdf2txt' with LV's 'System Exec.vi' to generate a temporary txt file, which then could be opened and analysed. If I find my old VI I'll post it here..though it's not difficult to rewrite it once you have the pdf2txt.exe. -Franz

I also thought about using the .NET file dialog since I want to include a file preview thumbnail within the dialog (something which is not possible with LV's built-in dialog, AFAIK). I found this thread as a starting point for using .NET and of course was stuck then by the 'dialog not on top' problem. There is a workaround though. (I couldn't get the other workaround offered in this thread to work) By using a WinAPI call ('Move Window to top.vi' from lvwutil32.llb) the dialog can be brought to top: the subVI code is this: Interestingly this does not work when the 'Move window to top' call is in the subVI... -Franz

ZITAT(yasmeen85 @ Dec 8 2007, 06:23 PM) Yasmeen, you might want to have a look at the example ...\National Instruments\LabVIEW 8.5\examples\general\uievents.llb\New Event Handler.vi The example is meant as an introduction how to use (user-)event handling in Labview, but it also may help to answer you question. In the example 2 subVIs open their front panel when a corresponding button on the main VI is pressed. The subVIs are declared to be 'modal' in this example: That means that no other LV window is accessible before the modal window is closed again. Therefore no two sub-windows can be opened at the same time. If you want to switch off the 'modal' behavior please look under the topic 'Customize Window Appearance Dialog Box' in the LV help to see how to proceed. However, in the given example switching off 'modal' would not make sense since the 'Analyze' sub-window can only do a meaningful job when the 'Aquire' sub-window (or subVI for that matter) has terminated. Whether a subVI with opened front panel should me made 'modal' or not depends on the intended application. Hope this helps, -Franz

AFAIK those VIs are part of the Wavelet toolkit, which needs to be purchased separately addition: Searching for 'detrend' in www.ni.com I found that there also is a 'detrend' function in Mathscript. And the wavelet toolkit I couldn't find anymore, maybe it is now integrated into the Advanced Signal Processing toolkit

Thanks, I knew that one and I used it long time ago for retrieving data that had been measured with a 'quick&dirty' assembled aquisition program. I hadn't even found the time to write the 'save to file' part of the VI at that time and therefore used the data logging feature of LV. In order to retrieve the data for processing later I used this 'enable data base' access trick. It all worked nicely but at one point I changed the main VI (added or modified controls) and didn't save the old version. I could no longer access the old log files, since they are binary and could only be read when the controls and indicators were exactly as specified in the log file's header part. After that bad experience I stayed away from the log files, but I agree that the technique might be helpfule here. I'll check it out. But for now I finished the XML approach and I attach the first version here, maybe it is helpful for others: Download File:post-833-1163876298.vi regards Franz Thanks for the tip, Ton! I actually had thought about that but I had problems lately to download the OpenG software. Do you know a working download link? Franz

I can't get the 'Convert from XML' function to work when the input type is a variant, see attached code. Am I doing something wrong, or is this a bug? Code picture: Code: Download File:post-833-1163832727.vi ********** UPDATE*********** I found the answer to my question at this ni.com site where it says: "Although you can flatten LabVIEW variant data to XML, attempting to unflatten variant data from XML results in an empty LabVIEW variant". So it's a feature, not a bug. Background: I wanted to write a VI which stores all control values of its calling VI to an XML file, and reads them back. In my first approach I had accessed the calling VI's 'Panel' refnum to obtain the Controls[] refnum array and from them the Value property, which is a Variant. That I wanted to write and read to XML. This does not work due to the reason above. I will now try to use the 'Get all control values' method node to access the calling VI's controls. That method delivers a (flat data|type desc) pair for each control, which should allow to do what I want. BTW: A VI doing what I describe above should have been written by someone already, but I couldn't find it. I'd be grateful if there is such a VI and somone can point me to it. -Franz

To me it seems that Search and Replace Pattern.vi IS able to remove the tags, see attched example. Can you post a specific example where it doesn't work? (Or maybe I misunderstood what you want to achieve?) -Franz Download File:post-833-1160287566.vi

mpa, if you listen to the Mistaken Podcast you will know that a native OO in LabVIEW is not too far in the future. It might be worth while to wait for it. -Franz

I had a look at your equation. If I read it correctly, you can substitute z:=x+a*y and then bring the equation to the form x=f(z). You could then try to use this for non-linear fitting, treating x as the dependent and z as the independent variable. Also I would recommend you normalize your values in such a way that reasonably sized coefficients occur, not ones which differ by 23 orders of magnitude. That would probably help to avoid numerical errors -Franz

Is there somewhere an up-to-date listing of these undocumented .ini settings? I used to look them up on Brain Renkens page http://labview.brianrenken.com/INI/ (and the LAVA FAQ http://forums.lavag.org/index.php?showtopic=299 also still refers to that URL), but I cannot find this supersecreteprivate stuff there. regards Franz

o.k., I got it running now. The execution speed results you obtained are indeed very interesting. I basically could confirm all the timings you obtained. In addition to your tests I added one where the whole array is passed to the subroutine (which contains what you call 'inline' code). Interestingly the subroutine performs slightly faster when you set the priority not to 'subroutine', but to 'time crritical' only. The fastest pure-LV solution i came up with was one where the formula node (with external indexing) is put in a 'time critical' sub-VI, and where the cos calculation is replaced by sqrt(1- sin*sin): It is nearly as fast as the lcc-array solution, as the green line in the following diagram shows (the diagram lists msec used for 500000 array length): So the LV solution is only 10% slower than the lcc one (and faster than fortran), unless you speed up the dll code by avoiding the cos calculation there, too. Remarkably, the timings of the two LV-subroutine solutions (black and green lines in the diagram) are much more constant than the timings of the inline, lccc and fortran solutions, which sometimes are longer due to some backgrounf activity in the system. That becomes especially obvious when I did not turn of my PC's DSL network. The following diagram shows the timings with network on (in the above diagram it had been off): The black and green curves are 'unimpressed' by the background activity, the others obviously not. (I wonder if they become more stable, or even faster, when 'wrapped' into 'time critical' subVI) In conclusion, I would say that it is possible to have a fast floating point meth in LV which nearly reaches a DLL implemetation. Inline code is not necessary, IMO, since the 'time critical' subVI method can be used. BTW: I obtained my results with a beta version of LV 8.2, since I had all older LVs uninstalled. I attach a copy of my VIs which is saved for LV 8.0: Download File:post-833-1148831147.zip

Hi bsvingen, LV complains about a missing 'salflibc.dll'. Could you post that one, too?

I noticed that LV 8.0.1 (on Windows XP Home edition) freezes during startup when the clipboard contains some Mbytes of data. Here's what I did: - Open a text file (2.7 MByte ASCII data) with notepad - select all text - press Ctrl-C - start Labview result: LV hangs (showing the 'Finishing Initialization' message on the splash screen, lower right corner) cure: shutdown LV remove data from clipboard start LV Is this behavior also seen by others?

Such a control is a standard in Labview since version 2.52 (or such). It's called LED button. Or did I miss the point about your new XControl? LED button:

I usually call them 'intelligent globals' -Franz

You don't need the OpenG tools, it can of course be done with plain LabVIEW: Download File:post-833-1135437245.vi -Franz

Peter, whatever you do to your data depends on what information you want to extract. If you want curvature (=2nd derivative), go with method iii) above, I can hardly figure a better way to find a 2nd derivative for noisy data. If you want to compare complete curves, and the curvature is only a tool you use for comparison, there might be better ways to make a reliable comparison, but that depends on details of you setup which I do not know. But in any case, you should try to reduce the noise in you data beforehand as good as possible. E.g. I've seen 2 or 3 outliers in your data (outliers in the X-data set) which you should try to avoid or, if unavoidable, exclude from the analysis. Another comment (again without knowing the details): if a derivative is the signal of interest, it is often best to do some kind of modulation spectroscopy, i.e. you modulate the signal which represents your x-axis sinusoidally with a small amplitude and detect the y-signal with a lock-in amplifier. Then you measure directly the 1st deivative with a much better signal to noise ratio than calculating it from y(x) data. But probably a modulation is not possible in your setup? good luck Franz

Hi Peter, Method iii is the one described in the 3rd paragraph of my last posting: "Then the best solution would be to perform a polynomial fit to a subset of the original data which is centered symmetrically around point (Xi,Yi). Take 2N+1 data Xi-N, ... , Xi, ... , Xi+N (and the corresponding Yi-N,...,Yi+N) and fit a polynomial, then take the (analytical) 2nd derivative at point Xi as an estimate of the 2nd derivative of the original dataset." N is the number of data to the left and to the right of a specific data point i, so the total number of data taken for a polynomial fit is 2N+1. Data points i towards the beginning and end of the dataset may have less than N points to the left or right, and then of course less than 2N+1 data are taken. Example for dataset of size m: For N=2 the following fits are performed: for i=0 points 0,1,2 are fitted for i=1 points 0,1,2,3 are fitted for i=2 points 0,1,2,3,4 are fitted for i=3 points 1,2,3,4,5 are fitted for i=4 points 2,3,4,5,6 are fitted . . . for i=m points m-2,m-1,m are fitted I think what I implemented is called a smoothing polynomial filter, but here it is not used to filter the original data, rather only the 2nd derivatives of the data are obtained. If for each data point Xi a new Yi were computed from the polynomial and would replace the original Yi, one would indeed have the implementation of a smoothing polynomial filter. The VI I posted can be easily modified for that. regards Franz

Have a look at this example: ...\LabVIEW 7.0\examples\general\uievents.llb\Draw Graph with Events.vi -Franz