Non-linear function Lev - Mar - output gradient functions reference table?

Similar Questions

• Adjustment of the non-linear curve Lev - Mar ignores entry model

  I use the curves of Lev - nonlinear Mar made to fit two of the data in the same VI.  However, the second time I call the Lev. VI - Mar, it ignores the model and continues to use the first model.  When I run Lev - Mar outside my VI, it can adapt to these two sets of data correctly using two different models.  How can I get the VI to use the correct model of the second time I called in my VI?

  I'm using Labview 8.0 on windows XP.

  The VI itself is not protected by, but it is part of a library passworded, indirectly blocking the operation.

  You can still select all the code and copy it into a new VI, the hook upwards all connectors.

  You can also browse the VI Explorer and copy it. The copy of the give a new name, open it and log out of the library (File menu) to fix the broken arrow.

  I think you can also change the original in place and press "Save". It does not have a password and will overwrite the existing VI. Don't make any mistakes here!

• Questions on the non-linear curve Lem - Mar vi

  Hello, I try to adapt my data for my model and stuck now.

  Before you ask, here is my model to fit:

  t = k * I + Ja + uw + T * tanh(A*w)

  I have the same numbers of sets of data to I, a, w, t.

  I want to know the best settings games made of K, J, u, T,.

  I know it is underconstrained and there could be many solutions but it's okay anyway.

  The solution is use in my application.

  I tried to build a running model vi and vi, and the vi runs and gives me a very crude answer together.

  Which means, he's only 10 ~ 12 iterations and it ends and gives the final solution, even if I put an end criteria very strictly.

  I want to run at least 10000 or more iterations to adjust to my data, but it doesn't seem to give a lead.

  Can I request a notice in this situation?

  Here's my vi and data sets.

  The real problem is built-in model.vi. Partial derivatives are false. In fact each partial derivative is calculated correctly, but they are in the wrong order in table f'(X,a). The parameters in a table are k u T A J. Derivatives are dt/dJ, dk/dt, dt /, dt/dt and dt / dA. Note that dJ and dk derivatives are in reverse order compared to the parameters. When I change the order, made it very similar to the measured data and the residue is much smaller.

  Several times should not explicitly calculate partial derivatives. VI connection will perform digital differentiation if f'(X,a) table is empty.

  Most of the mathematical functions are polymorphic. They can take pictures as inputs as well as scalars. The model fitting VI is not the loop when you take advantage of polymorphism.

  Lynn

  

• spend a CVI to TestStand function reference tables

  I need to switch tables (double, for example) a CVI function (usually a dll), return to TestStand.  and vice versa.

  I followed a method that uses features of TestStand CVI such as 'TS_PropertyGetValNumber' and 'TS_PropertySetValString' and I understand how simple values, but the tables are killing me.   I do not see why it would be so difficult, so I must be missing something fundamental

  Here is a simple example of what I'm doing.   I need to add a way to pass an allocated array of doubles (as declared and held in TestStand) in the CVI function where it is called 'values', have my CVI function fill this table of the 'values' and then pass the array back.

  void TestStand_DUT_Transfer (CAObjHandle seqContextCVI, char reportText [1024],)
  
                               short * errorOccurred, long * errorCode, char errorMsg [1024])
  
  {
  
      error int = 0;
  
      char response [DUT_TS_MAX_BUF_SIZE] = {'\0'};
  
      Double delayResponse = 0.0;
  
      ErrMsg errMsg = {'\0'};
  
      ERRORINFO errorInfo.
  
  get the double value of TS
  
      tsErrChk (TS_PropertyGetValNumber (seqContextCVI, & errorInfo, 'Properties.Delay',
  
                                         TS_PropOption_NoOptions, & delay));
  /*                                                                     */
  
      / *    How DO I GET AN ALLOCATED TEST DOUBLES TABLE?    */
  
      /*                                                                     */
  Send command to the device, return a response string and double values table
  
      
      DUT_TS_ErrChk (DUT_Transfer (delay, response, values));  //<=== here="" is="" "values"="">
  
  
  
  
      /*                                                                     */
  
      / *         I PASS SUSTAIN HOW THE VALUES BACK to THE TEST BENCH?         */
  
      /*                                                                     */
  Send the char string to TS
  
      tsErrChk (TS_PropertySetValString (seqContextCVI, & errorInfo, 'Properties.DUTResponse',
  
                                         TS_PropOption_NoOptions, response);
  Error:
  
      If (error! = NO_ERROR)
  
      {
  
          DUT_Error_Handler (error, error);
  
          * errorOccurred = TRUE;
  
          * error code = error;
  
          strcpy (errorMsg, errMsg);
  
      }
  
  }
  
  

  Thank you for the review.

  well, I received a response OR support.  I guess that's a common question since they have an example written, but for later use (since I couldn't find an answer by searching on forums), I will post it here:

  \Examples\AccessingArraysUsingAPI\UsingCVI

• Problem: Fitting Lev - Mar with error function

  Hello world

  I have very little experience with LabVIEW and I try for the first time to do some non-linear curve worthy data that I have.
  I've searched the forums for almost a day and could not find what I need. The problems are:

  (1) I need to fit to a function of the following type: P = Po/2 - in / 2 * erf (sqrt (2) *(x-xo) w), where the Po, xo and w are my settings.

  But in my error2.vi, I can't tie my y = sqrt (2) *(x-xo) variable w of the iron works at the entrance, because the erf.vi does not table 1 d as input and which gives as output as well. The output is another problem, as F(x,a) entry must be a 1 d array.

  (2) I read on the nonlinear CurveFit VI of Lev - Mar and I think I what to do. However, an I had problems in the wiring of my static VI reference to the F(x,a) entry in the Lev - Mar VI and it does not give me a cut wire only when I reference a strictly "VI reference typed". What does that mean? Why it works only with who?

  I know these are pretty basic doubts, but I tried to figure it out for some time and could not achieve.

  Thank you.

  PS * the fitting function (Subvi) is the error2.vi file.

  Try this. Seems to work very well (LabVIEW 2013).

  (do not try chart the best settings, graphics the best out of shape!)

  

• The non-linear curve fit lev mar problem

  Hi, I have a set of 10000 readings recorded every second. My goal to draw these vs time readings (1-10000 s) in logarithmic scale and adjust the exponential curve that results with my model equation: a1 * exp (t * b1) + a2 * exp (t * b2) + a3 * exp (t * b3) + a4 * exp (t * b4) and get the values of the coefficients (a1 to a4, b1 - b4). I changed the non-linear adjustment of lev - mar.vi according to my model. However, I ran into a problem.  I get the following: error-20041 occurred at LM.vi:5 to get on the curve of the NI_Gmath.lvlib:Nonlinear Possible reason (s): the system of equations can be solved because the input matrix is singular. I can't work on why I get this error. I enclose 3 files: the data file (values of Y), X = 1-10000; coating not get my model and vi vi.

  I'm using Labview 8

  I would appreciate your help and suggestions! Thank you very much in advance. ANU

  Hello

  @Jim-thank you very much... ur modified vi helped a lot... but a strange thing on the adjustment is that it depends a lot on the estimation of the coefficients... my model should have values of 'a' coeffs in the order of 10 ^-7 and 'b' should be higher around 10 ^-1. The initial proposal is amended the best coefficients made vary accordingly.

  I don't really know if this can b fixed... I enclose my vi.

  VI: - non - linear adjustment model, exponential branch.

  data - pol.txt

  I appreciate you all!

• Piecewise linear function fitting

  I have data which approximates the following function:

  f (x) = A; x<>

  f (x) = Bx + C; E<><>

  f (x) = D; x > F

  I am using the non-linear adjustment function and problems with a singular matrix error. According to me, I approached my settings quite well and the best track of the fitted curve seems fairly well aligned, but it seems that's not iterate through my approximations E and F and just using what I give him. Could someone take a look at my code and give me some additional tips? The points that I particularly need are the value 'A' and when f (x) = 0 of the second function. If there is an easier way to find these values, I'm all ears.

  Thank you

  Yes, you have only four parameters.

  1. Beginning level
  
  
  2. End level
  
  
  3. first x
  
  
  4. second x

  (interpolating linearly between the first and second x from the first to the second level).

  See attachment for a quick project.

• Curve adjustment not linear function

  Hello everyone:

  I'm a little new here and at the same time a new learner for labview. My need for laboratory to adjust the data which are not linear, so, I choose to use the model non-linear curve VI. But when I run the VI, the error is that:NI_Gmath.lvlib:LM formula function.vi:7290001 string, or other displayments of the error. I tried several times, but unfortunately didn't. The problem may be the expression of the function form. Moreover, the design of the VI is not mine, it's Forum OR. Any constructive suggestions will be welcome.

  The form:

  y = Y0 + (Nr * cos (A)) + *(x-W1)/((x-W1) a1 ^ 2 + L1 ^ 2) + a2 *(x-W2)/((x-W2) ^ 2 + L2 ^ 2)

  In fact, the form is very long, I just write some.

  
  

• Non-linear curve shape VI don't, get error-20068

  Hi, I have a problem of raw data to a formula of mounting. The formula is f (x) = - ax + b + c (x/d) ^ e. I use the non-linear curve Fit VI, Lev - Mar: the formula string. I'm able to calculate 4 5 parameters (a, b, c and d). I can't calculate, but it should be around 10. When you run the VI, it gives me "error-20068 occurred at NI_Gmath.lvib:LM get new coefficients.vi:1. " "Analysis: input parameters has at least one element that is Inf, NaN, DBL_MAX or DBL_MIN"

  It is tracing the equation based on the initial settings without actually finding the best adjustment of the parameters. I also tried using the VI version to create the formula, but it gives me the same error. What can I do to avoid this error? I have attached the vi and a data file.

  

  Some of your top X values are negative. Remove them and things will work fine.

  (You get a negative signal for the exponentiation, which is allowed if the entry is complex or the exponent is an integer. This isn't the case here, where the exponent is not an integer. The exponent is an integer in the first function call, but not more once, trying to calculate the partial derivatives of the model. Try with a hypothesis of 9.9 instead of 10, and it will fail immediately)

• apply restrictions for the non-linear curve fit

  Hello Forum users,.

  I am currently working on a VI control which is supposed to create a specific model of pressure inside a hollow tube to provide a test environment for pressure sensors. The details are many and complicated, so let's say I am sure that my formula to calculate this profile according to the pressures inside the hollow rings around this tube will work.

  To find the correct pressure for each ring values, I've linked to a model VI containing this form to Lev. - Mar algorithm (the non-linear curve adjustment) and let it run.

  Technically, there is no problem and Lev - Mar find values to adjust the function for the values (not perfectly sure, but close enough).

  The problem is, however, that, since the device, once suitable values for the positioning and size of the rings are found, must be built, the simulated pressure rings perhaps intersect not between them. To apply this rule, I added a check to my VI of model and if the values passed to Lev - Mar breaking the rules, the VI model gives a matrix of zeros to follow him (I tried an empty array, but that only leads to error messages).

  This solution did not work. Lev - Mar seems to ignore these cases always looks for values that break my rules (and if I put these values through my model VI, I get a matrix of zeros, as expected, so the audit seems to work).

  Perhaps I misunderstood the algorithm of Lev - Mar and it does not actually check each possible defined coefficients of finds.

  Is it possible to adapt to any function of a set of values while keeping the predefined boundary conditions?

  Oh, before I forget:

  I use LabVIEW version 8.2 in the Institute, because the workshop systems is not installed 8.5 for some reason any.

  Thanks in advance

  Thaliur

  Hi Thaliur,

  Thanks for posting on our forums.

  I understand your request you expect the algorithm to ignore a case to all zeros in the table. However, it is not implemented like this.

  Good news is, its source code can be edited and you could save your own personalized version of the algorithm of screws it is to you that you just add a check for a matrix of zeros or simply pass another parameter which indicates only a case of "broken rules". Then you would not have to continue the calculation.

  If I misunderstood your question, please clarify this. You can also post a code for further explanation, if you wish.

  Good luck with the project!

  Peter

• Problem to adjust the data using the algorithm of lev - mar...

  Hello

  I'm a casual user of LV, and I need signal level using a non-linear custom model. The signal is basically a decay of exp (order 1) with a continuous component, so it's pretty simple.

  When I apply the routine of Lev - Mar's non-linear editing, I've always had the famous "an exception has occurred in externally called by a function of the call library node. This could have corrupted memory of LabView. Save any work., etc.. VIwas stopped to node "" a call to "NI_AALPro.lvlib: Real - Decomposition.vi of SWINE vesicular disease.

  The thing is I've already adapted successfully some basic (linear model) data using this form of Lev - Mar non-linear... but it won't work this time... and I don't see why.

  Could you watch my VI and model definition and tell me what I need to improve, and what might cause the problem? The main VI (TPV_Fit_ExpDec1_v1.0.vi) open a text file that contains my data (3 columns: time, a pulse (not useful for editing), the signal to fit). At the beginning, I isolate the part of the signal that matches t > = 0, because it is where begins the exponential decay. So I want just to get the part. I join the main VI, a txt file containing typical data, and made the VI that define the model to the lev-mark function.

  I would appreciate your help and suggestions!

  Thank you very much in advance.

  MY VERSION of LABVIEW is the 8.2

  JB

  Here's a quick rewrite. You should ALWAYS figure the curve for the initial parameter estimates see if they are in the ballpark. Rather than modify the data, you could just put the weight to zero for negatvie x. see if it works better.

  

• coefficients variables semi in a non-linear curve fit

  Hi all

  I use a curved Lev - Mar not linear adjustment vi to fit a custom to my data function. The function is a set of Gaussian functions and an offset. I mean to constrain the width of one or more of the Gaussian curves in the function. I can do this by changing the values in the equation in the model description in the block diagram, but how to do this easily through the front?

  These width values will not be floated in the adjustment.

  Thank you!

  Unfortunately, the limited version was added in LabVIEW 8.5.  You could use the 'data' variant to pass the value of the stress sigma model and adjust the location and amplitude values. This means that your entry of Lev - Mar estimate does not include the values of sigma.  The value of sigma fixed wire entry "data".  Then depending on your model take data entry (type variant), cast to a value double precision and insert into the locations in your model formula.

  -Jim

• Error-20003 of curve non linear adjustment LM with a VI curve as a good model

  Hello

  I was stuck for a while now, by an error when I use the non-linear curve mount LM with a VI as the model curve adjustment. The code error is-20003, and occurs in the "LM get new coefficients ' vi and analysis, said"the number of samples must be > 0 ". I checked a number of things, but I can't get rid of it. The VI is quite simple: it uses a database of three sets of numbers (or ghosts) and it aims to adjust a curve that is the sum of these three spectra to determine the multiplicative coefficient associated with each spectrum. The code is attached to this message, thank you so much for any input!

  Looks like your model function has default data stored in the output of f'(x,a).  Try to empty the table (be sure to "Save as default" after emptying) and run again.  This solved the problem on my machine.

  Apart from this specific error, it seems that your model is linear in the spectrum of the molecule, so maybe using Fit.vi linear General is a better match for your problem?  The two algorithms give the same results on my machine.

  -Jim

• The non-linear curve slope

  Hi all

  How can I get the slope of a particular point in the non-linear curve? I use Lev - Mar curve fitting is not linear.  The slope is to determine the dynamic resistance of the current-voltage curve of diode if dynamic resistance = 1/slope. Kindly help...

  
  

• Non-linear curve Fit error 20068?

  Trying to do a simple 3-exponential decay curve nonlinear.  I have a copy of this work in the other screws, but it doesn't seem to work in this VI.  I use "Scalablemultiexponentialdecay" of Altenbach as a VI/template model.  Data that I'm trying to adapt are a series simple decomposition RC, yes I realize that should not have 3 exponential components, it's just the model data.  I am able to adapt with the Fit exponential function built in to the Math palette, but which only works if the input bounds parameter is wired and with rational constraints.  However, I get an error on the adjustment of the non-linear curve that I understand not (photo attached) indicating that an INF or NaN is done in the settings.  I don't see where this is going...

  Any questions or help is appreciated.

  

  

  I thought so, only 0 s for the 2nd two exponentials.  But, if I replace all the guess seededes with the same as the simple exponential Installer, it converges without error.   I guess I didn't know it was that sensitive.  Thank you.