read several off file lvm 2D arrays

Similar Questions

• How to read my waveform data from a file LVM?

  I have collected a form of wave and saved using the file LVM format. I would read the waveform in labview and view with its timestamp and assigned name. The only way that I could read the data in Labview was to convert it to an array of number. I thought that if you could write a waveform and save all data, you should be able to read it back quite easily. I have included my LVM file and two simple programs. The program I use is much larger, but these two programs are representative of what I'm trying to accomplish.

  Thank you

  Eric,

  I am pleased that you have something that can work even if it is not ideal.
  I close this service request, but I thought that I'll let you know that
  because of your issues, I have revised article in the Knowledge Base on
  timestamps and verified for accuracy and thought you should know.

  What is the precision of the timestamp of the waveform returned by my NOR-DAQmx
  Device?
  http://digital.NI.com/public.nsf/allkb/5D42CCB17A70A06686256DBA007C5EEA?OpenDocument

  Concerning

  Vince Methot
  Technical sales engineer
  National Instruments

• read the cluster of the specification of the file LVM

  Does anyone have a clever solution to read programmatically masks specification limit (for waveform limit testing) of a file LVM?

  I used the Express VI 'Mask and limit review' to create masks, which I saved as LVM using the function of recording data.

  I don't want to use the Express VI to itself test, because the test is in a Subvi is called in a loop; each iteration of the loop must send different masks at the limit of Test.vi which is in my sub - VI.

  Thank you

  -one

  Hi Andy,.

  LVM is a text file for reading using the function of reading files.

  After that, I search the string to find where the data starts using the match pattern

  You then process the rest of the string to the file, and then use spreadsheet string in array with a tab as the delimiter.

  There are tabs at the beginning of each line and extra line break at the end so I used subset of the table in order to avoid these areas. It may not work every time, but you can fix that when you encounter a problem.

  

  see you soon

  David

• could not read my file LVM

  Hello world

  I created this file LVM after the acquisition of my signal. Right now I have a problem of extracting data from this file LVM. For example the data in the cell B24 to J24.

  I didn't have something like that because it should be relatively simple. I used loops and methods to extract the data, but she return me the value NaN or another number. I don't know what is happening.

  The attachment is LVM I created. Please help me with this, thank you

  PX

  Use the Express VI to convert the type of dynamic data in a 2D array.  Then the index on the column in your table.

  You can also check the integrity of your data.  In your file, the first line of data is fairly complete.  Later lines have several empty columns before and after the 4 columns of data.

  When I ran the attached VI extract, I noticed she has imported the data, but the columns other lines not aligned with the first complete line in the same way they do when I saw your file in Notepad.  You will get many NaN for wherever your data are empty.

  

• SMU remote system do not read file .lvm

  I try to get my remote system (SMU remote system) to send a signal of analog voltage by reading a file .lvm.

  I have a project in real time implemented, and under my remote system, I have a VI that is supposed to give a signal of analog voltage.

  The implementation of VI begins by reading a file position (.lvm). After that, it is connected to a DAQ assistant.

  I'm already sure that everything is connected properly, and that it is the right channel. The reason why I'm sure is because in the DAQ assistant window, I can click on "run" in order to send a test signal. I am able to capture this signal to test with an oscilloscope. Therefore, I am sure that the system is all set up correctly.

  Finally, I don't know if it's important, but the measure file he was reading is located in my host. I don't know if I deploy when the VI to the target, if the measurement file is sent to the remote system with the VI.

  I was wondering if someone could help me please.

  Thank you

  Leon

  Hi Leon,

  If I understand correctly, you are trying to read a file .lvm waveform data and send this waveform through your SMU system. What devices are specifically using (chassis, modules...)? What exactly happens when you run the VI? You see errors? If so, what are the codes that come with these errors? Additional information on what the file .lvm would be also useful. What are the functions you use to play the .lvm file?

  Kind regards

• Cannot read the timestamp of the file LVM in table or export to Excel

  Good afternoon!

  Im having issues return timestamps from a LVM file and an excel file.

  Ulitmately, I have a series of files LVM with 6 channels of data and timestamps of correspodning.

  When I read the back files in a table, the channel values are analyzed, but the timestamp is no where. The channel data then exported successfully to an excel sheet (less the time stamps).

  How can I extract the timestamps with the channel data and bring them into an excel sheet?

  NOTE: I do not know you can open the file LVM directly in excel, however, information is not "analysable.

  I appreciate the toughts. I have attached my experimental code as well as the data set, I am trying to extract. I have also included a spreadsheet excel destination.

  Hi, ASAT,.

  Is there a reason that you do not simply write it as File.vi to write your signal data in the excel worksheet? It is an easy way to put in your signal data to an excel spreadsheet (see file attachment). You can also view the code in this Express VI to see how this is achieved.

• Reading several files / locate the data source during execution

  Hi all
  
  I have a requirement of the company in which I need to read files to different folders. This system is not hosting the ODI agent. There are two folders, the folder A and folder b. Two records may have any number of files. My intention is to read the files in a folder and write the data to a table in a database that resides in another system. This forms a flow for me. For the B folder, I have a similar flow. All files (in the folder A and folder B) have the same structure. The requirement is to read A book during the week and the B folder on the weekend. The system that has the database also runs the ODI agent.
  
  Here are my questions:
  
  1. How can I read several files one by one in a folder? Because the read files must be archived, they need to be written in a different folder, file C (for example). How do you archive part? Please note that this machine does not run ODI agent (network share could be an option, but we try to avoid it.
  
  2. can I have only an interface to read files in folder A and folder B? Everything else remains the same (the processing logic/transformations etc.). Indeed, is there a way to dynamically switch between two files (using a variable, perhaps).
  
  I've not worked with files and so any help is greatly appreciated.
  
  Edited by: Sankash 7 May 2009 08:24

  Hi Sankash,

  Hopefully I can help you achieve this task.

  Please go through this link

  Re: import files in a table

  1. you can update the status of the process of the files in a journal/temp table.
  Based on the State of the (transformed) file in the table, you can check the files that has completed its process correctly.

  machine does not run ODI agent:-J' have it is implemented the same type of scenario, in which I am downlading all the files in a common location and treat it from there.

  2. one of the solutions is that: -.

  create two interface with the same structure, but the source table must point to the folder A and B
  Create a variable (week/check) and based on the value, you can call the interfaces.

  second option: -.

  If you're downlaoding the files in a common location, you can reach the spot through a single interface (down load files from folder A or B according to in week/weelend)

  3. If all the files have the same structure, you need only a data store and it should be a variable data store.

  If something is not not clear please me ping / mail to my id (good that now I don't get enough time to go through the forum discussions)

  Also if you need I can send you a diagram wokflow for this loop (read multiple files one by one in a folder)

  Kind regards
  Pascale of M

• Not able to read the text file several times - Bug?

  I open the Refnum to a text file by starting my software and I'll keep the file open until the software works. I read a text file when an event occurs. The problem that I'm facing here is when I read that the file 1st time Lily can't read the text of the file but when I read it to get even empty string only. Could someone help me understand why this happens.

  

  A race condition?  What's with the two readings at the same time?  Keep the opened file is not a problem, but remember that there is a file pointer.  If you read empty strings, it's probably because you're at the end of the file.  Use Set leader VI to set Position is for the beginning of the file.

• worksheet to no array string not read any .txt file

  I am very new to Labview.

  I'm reading a .txt (positions.txt) with reading In.vi file.

  However, the result is not what I wish it to be. The first 3 rows are omitted from the result table, but I don't know why.

  I followed the tutorials and can't see why the resulting table starts 4th.

  Hi marvin,.

  is there a reason why you want to create a table of dimension 4?

  If your reading the LabVIEW has helped, how LabVIEW formats (or hope) spreadsheets for table dimensions > 2?

  Solution:

  Change the constant matrix and indicator in a 2D table!

• How to convert one or more files LVM of large file TDMS (500 MB, 32 M samples - 2 channels)

  I would like to be able to read at least 4 million lines of data total 32 million lines at a time. The TDMS file has given for 2 channels and no time data. If I can convert TDMS files in one or more files LVM, I can read large files of LVM using the JMP software.  I'm using Labview 2009. Please provide suggestions.

  Thanks in advance. Best regards, Manish (Univ of a to z)

  Hi Manish,

  For your problem with is .tdms to .lvm, take a look at this forum and This example of community.  I checked out, and in my opinion, he should be able to work well for you in regards to creating multiple files .lvm from single .tdms file.  The only thing that could be a problem is the time requirement to enter all in LV, and saves data to several files, but you will encounter when you work with large consumed data.

  I would also suggest that you take a look at tiara if you are searching by analyzing large data sets.  The program is designed to manage large sets of data and make the analyzation on the data.

• Read/write PDM files

  I'm looking for TDMS files as a way to save disk space for long trials.

  I have trouble finding a clear tutorial on how to write several channels (but I think I got including this one), but more specifically, how to read several channels on a sort of a waveform graph. My research did not give much.

  Is there a better data format to use?

  Rick

  Talk wrote:

  So if I understand well to do a PDM read function for each registered channel?

  No. one is the reading of many channels.  In this case it receives all channels waveform data in the data group measured.  You could also provide an array of channel names if you want to be more specific.  But all channels from a single reading must be of the same data type.  That's why the other two readings are separated.

• Can LabWindows libraries call function inherited from read the Datalog file?

  We are currently updating some old software written in LabVIEW 6.0.3 to Java. One of the features of the original software is to create data files using the function "Write Datalog" and also remind these databases later using 'Read Datalog'.  To maintain backward compatibility with old data users, we want that new software to also be able to read and display the old datalogs.  I have read several posts here about how the only way to get data off datalogs uses the function 'Reading Datalog' of the same version of LabVIEW to write the paper in the first place. I have the original LabVIEW code so I don't know the structure of the data that has been written.

  I want to know if there is the same function in LabWindows libraries.  Specifically is there is no support for a 6.0.3% version of the function of reading Datalog to support interfacing with a call to java?

  To knock out a possible solution, this software is shared with clients.  We want to avoid the way of compiling an executable separated from LabVIEW to be distributed with the main Java software which batch processes all the old data files in reading them with the old function of LabVIEW and spitting out files in a new format.  We would prefer for the old files to be transparent open into the new software.

  WARNING: I use LabVIEW for dark days before the invention of the button cancel, but never touched LabWindows/CVI. Please enter slowly so I will understand

  Thank you all!

  I guess that is not a built-in library capable of reading files datalog LabVIEW simply because they do not have a fixed format... Even in LV, you will need to pass the data structure for the opening function in order to be able to read the data back.

  Searching the forum I found this discussion that can give you useful to begin with.

  Apparently, you need detect the beginning of the section of the data file after the initials "DTLG" and rest of the header (which is the part not documented). After this point, read the file should be simple if you know the data structure the program writer used. The data > storage section of LabVIEW help can give you information about the content of the memory of each type of data used.

  A simple test, I did write the clusters with a string and an integer shows that: 1. section of data begins at offset 0x22F; 2. the cluster is poured into the file preceded an int with the length of the string; 3. documents may have a variable length according to the length of the string; 4. There are no bytes of padding between elements of the cluster; 5. records are packed in the file consecutively.

  I did this test using LabVIEW2009: it is possible that older files of LV are structured differently.

  An alternative to this is to generate a DLL in LabVIEW that reads files datalog and passes their content to the appellant. Since you are experienced in LV, you are certainly more comfortable than me by doing this.

• Retrieve a single value from a file .lvm

  I have a large batch of files of worksheet whose name is a timestamp. I am writing a program that will get the value of a specific cell (the same cell in each file), coupled with the timestamp and each of them as a pair of coordinates, then save in a master spreadsheet. The goal is to extract a point each of the 700 files I and compile them into a single file.

  However, I've never used Labview to read the files before. I saw some stuff on how to read an entire worksheet in a table, but I was wondering if there was a way to say to Labview to look into a file and extract a single value. I open .lvm in Excel files, so, in my mind, I would be taking, for example, cell D2. Is this feasible? Should I read the entire worksheet in an array and use the index to pick it up on the table? If I do, how I would specify cell J2 as an array index (I have no experience with the berries in Labview either). In addition, if you have any tips on how to record easily 700 pairs of coordinates, that came together in the order, to a single spreadsheet, that is my next task.

  Essentially- I need to extract a single value of a spreadsheet in, ideally, the simplest possible. In addition, pointers on how to save the numbers gathered at each iteration of a while loop to a single worksheet are welcome.

  Thanks in advance for the help!

  FYI I have LabView v8.6

  You can't say LabVIEW to 'out' a specific 'cell' more you can tell Notepad to do. the .lvm files are just text files. When you open them in Excel, the column separator (default tabs) show to put the values in columns. In LabVIEW measurement file VI reading to read .lvm files. It creates the dynamic data, wrong data type that is next to useless. You will need to convert this type of data in a table by using the function convert of DDT. Or, you can use the VI read spreadsheet file. This will give you a table directly. You can just remove the specific item using the table to Index.

• How to read the txt file that has words in between?

  Hi all

  I'm using Labview 8.2.

  I would like to read a text file.  I have given (after whenever he was on average more than 100 waveforms) several times recorded on the file.  The idea is to further improve the SNR in post processing by averaging once again the data (which was on average about 100 wave forms).

  I can get LabView to save the data in the file several times, then it keeps joins.

  The problem is to read data from labview, so I can on average now again.  The problem is the labview separates data sets with the following:

  "Channel 1".
  9925 samples
  Date 28/10/2008
  Time 17:16:11.638363
  X_Dimension time
  X 0 - 3.0125000000000013E - 3
  Delta_X 2.500000E - 6
  "End_of_Header."

  Then when I read it, he sees only the first set of data.

  Can someone tell me please how to read all the datasets under labview?

  I am attaching the file I want to read 'acquiredwaveform.txt' and the VI base (really basic btw) to play the file.

  Thank you

  This seems to be a standard LVM-file.  You can read segments of different data using the VI Express LVM loop (make sure that the file retains its extension .lvm).  I modified your example to show this.

  Note that my example is quite inefficient. Table of primitive construction causes a massive memory copy whenever it is used, and you would be probably better on average that you read in.  I made this way to make it more obvious how read segments of a file LVM.  In the process, I noticed that you have a good amount of phase jitter (zoom in on the graph of all the three waveforms).  With an average simple will make you smear on your waveforms.  You can either fix the problem in hardware (recommended) or phase shift your data so it lines up before on average.  If you need help with it, let us know.

• Automation of several Flash file by using the XML file 'mailing list '.

  I created a Flash interactive multi-fichiers 'demo' for a client. It is very well as a Web site (although he doesn't use it as a Web site) in the way it is stated that there is an index page which can then direct you to product categories, which you can click to see. Each 'page' contains the product (or product category) information, photos, diagrams, etc. There is nothing of Flash animation.

  My client also wants to be able to put in place so that the demo runs automatically in a configurable XML file. My ActionScript skills are fairly limited, but I was able to by using ActionScript 3 to load and read XML file. A loop using 'for', I am able to read the XML file and returns the path of each Flash file and the time that each file must be displayed (my client asked that he able to configure the duration of each page as well).

  I created a charger for each video clip and a timer for the duration. Unfortunately, the thing that throws me off is that when I try to load the clip (as the last element in the loop for), it reads the entire XML file, returns all the clips and the durations (I use trace to see this) before loading the clip. Thus, the single loaded clip is the last reading of the XML file.

  As I said, I'm not very good at ActionScript, so everything I managed to combine was internet tutorials.

  This is my code:

  var xmlLoader:URLLoader = new URLLoader();

  xmlLoader.addEventListener (Event.COMPLETE, xmlLoaded);

  var mcLoader:Loader = new Loader();
  mcLoader.contentLoaderInfo.addEventListener (Event.INIT, playClip);

  var mcCurrent:MovieClip = new MovieClip();
  stage.addChild (mcCurrent);

  var xml;

  function playClip(e:Event):void
  {
  trace("Function:playClip");
  stage.removeChild (mcCurrent);
  mcCurrent = MovieClip (mcLoader.content);
  mcLoader.unload ();
  stage.addChild (mcCurrent);
  }

  function xmlLoaded(e:Event):void
  {
  trace ("function: xmlLoaded");
  XML = new XML (e.target.data);
  
  var cl:XMLList = xml.clip;
  for (var i: uint = 0; i < cl.length (); i ++)
  {
  trace ("Begin"for"loop");
  trace ("variable" i "is" + i);

  clipPath var = cl[i].@path;
  var delay = cl[i].@duration;

  trace ("Clip path is" + clipPath);
  trace ("Display for" + delay);
  
  mcLoader.load (new URLRequest (clipPath));
  }
  }

  xmlLoader.load (new URLRequest ("filerunlist.xml"));

  
  I removed the timer event because, like all the rest was repeated until whatever it is obtained, so I wanted to figure out out to get the charger clip (mcLoader) to load the clip for each file, before I realized where put in the time to make sure each element is displayed for the appropriate duration. I suspect that the timer event must occur in the function "playClip", but that it would take advice on that as well.

  Thanks to anyone who can help me understand this.

  You need to do in the service of parsing xml is just to store all data in a table.  You will use while an array element after another through some timer control you set up, access each file in the order that they are stored in the table.  You do not load in this function, all data storage, and when finished, the last line of this function outside the loop, fires at any function you have who begins to treat the first element of the array.

  For example, to store the data objects in the array...

  var clipData:Array = new Array();   store your data xml here

  var clipToShow:uint = 0;                   use later in the function showClip

  function xmlLoaded(e:Event):void
  {
  trace ("function: xmlLoaded");
  XML = new XML (e.target.data);
     
  var cl:XMLList = xml.clip;
  for (var i: uint = 0; i
  {
  clipArray.push ({clipPath: cl[i].@path, delay: cl[i].@duration});

  }

  showClip();
  }

  function showClip() {}

  Regardless of the process of loading .clipPath clipArray [clipToShow]

  and using clipArray [clipToShow] .delay to start some timer is involved

  the timer handler function calls this function when it is run

  clipToShow += 1;   increment the counter for the next clip online

  }

  If you are not comfortable/familiar with the approach of the object, then you could also store the clip and delay data in two separate tables.