Polynomial function

Similar Questions

• Make an adjustment in line with the Vision Assistant for a polynomial function?

  Hello

  I have the following problem: I have a laser beam which a (non-linear) line on a wall. For this line, I need to know (exactly) mathematical

  function. That's why I can get a picture of the line, but I don't know how I can extract the mathematical function with a line fit for example. If I could "convert."

  the line at points that I would use the line fit function to LabView that should work without problem.

  Is there a way to solve the problem with vision assistant or... ?

  Thanks in advance

  Hello

  after thresholding, this should work:

  

  False case just by...

  Best regards

  K

• Why can I get two different results from the same coefficients?

  I get two different results of the evaluation of the polynomial function.

  For the first, I get the coefficients of a polynomial function to adapt.  I feed the coefficients of the function made the function Eval Poly and get the correct 12.8582 result when I evaluate 49940.

  For the second, I create constant array of values that have been returned by the polynomial Fit function (I typed in).  However, I get an incorrect result of - 120.7913 when I feed the constant table the function Eval Poly when I evauate 49940.

  How this can happen when I use the same values in table?

  A picture of what I explained is attached.

  Hi Altran,

  are you sure about using the 'same '?

  You compare them? Do you have (at least) set them to 17 digits display properties?

  Please attach a VI instead of an image...

• "Residue" in general polynomial Fit function

  Did anyone of you statistics fans understand how LabVIEW calculates the output of 'residue' in the service of "General polynomial worthy?  How is it related to the R ^ 2 value on a polynomial trendline Excel.

  I tried to figure this out for hours, but aid LV files do not seem to have the info I'm looking for, and I can't find a good explanation on the line.

  Thank you

  FB

  I thought about it.  I was looking at the TOTAL error of all the elements, rather than the average error.

• First - Division of polynomial

  Quick questions, hoping someone can explain.

  I want to do first HP (2 x ^ 2 + x + 6) /(x+1)

  When I enter quot(2x^2+x+6,x+1) I get 2 x-1, but he neglects to tell me about the rest of (7 / x + 1) is this nbehaviour expected? How can I get a complete result?

  Thanks in advance

  Paul

  Hi, Paul!

  Functions of the polynomial division:

  quot - quotient only.

  REM - rest only.

  quorem - the quotient and the remainder.

  Hope that helps!

• HP 50 g - reliable use of function DIV2

  Hello

  The "DIV2" function in the ARITH-> POLYNOMIAL menus did not accept my entries in the DIV2(X^5+X^4-...,X^2+X+1) form. My calculator back several times the message ' error DIV2: Type of Argument Bad. "

  I realized that the real value of the variable X was 6.1. The variable X can change its value several times over to make different calculations.

  In the meantime, to be safe for "DIV2", I stores an integer value (1, 2 or 3...) in the X variable before starting my work with DIV2. The reliable workflow resulting I can recommend for the HP 50 g is:

  (a) STO 1 > X (storing the value 1 to the variable X)

  (b) (available on a single key) ARITH

  (c) POLYNOMIAL (choice from the menu below)

  (d) DIV2 (choice from the menu below)

  (e) enter the two polynomials in DIV2 as described in the manual of HP

  (f) the calculator then displays "Purge the current variable" as an issue.

  (g) YES.

  (h) and now enjoy the results, which will show you DIV2.

  Look good and best wishes!

  Aficionado

  Hello

  When you do a symbolic work on the calculator, make sure the variables you use have NO values stored in them (that is, they do not exist in the VAR of the user).

  The calculator will attempt to use values stored in variables when performing the symbolic work. (Note, this is useful, it is possible to store another symbolic function in a variable with an interesting symbolic job).

  Other prerequisites (e.g. flag settings) DIV2:

  

  (Note: extracted the 50g of the advanced user reference.) ( http://h10032.www1.hp.com/ctg/Manual/c02836298.pdf )

  Best regards.

• Polynomial

  Hello!

  Using the line profile, I got a curve representative the trend of pixel on an image, now I want to apply for this curve a polynomial for a more linear trend eliminating bothers them; but before that I have to select(interpolate?) some points on this curve (this point will be the entrance to my polynomial). How can I do this?

  Yet once, your displayed such VI contains no data.

  You can use 'polynomial adjustment' to obtain the coefficients and then use "polynomial evaluation" to calculate the function for an arbitrary x ramp.

• Polynomial evaluation in FPGA

  Hi all
  I am currently facing a problem. I want to evaluate a 6 order polynom in the FPGA (in fact this function will be part of a larger VI). Here's what I put in place:
  Coef tab contains 7 following coefficients (from the RT):

  2734.91

  53.4378

  -2.02666

  0.0463295

  -0.000588338

  3.71736e - 06

  -9.06681e - 09

  When I sent this VI in the 2013 worker compile, I get the following error:

  LabVIEW FPGA: Compilation failed due to the overmapping of the resource.

  The FPGA VI does not fit on the FPGA target because the VI requires more resources
  that are available.

  Suggestions to eliminate the problem:
  Reduce the amount of logic in the VI
  Reduce the number of multiplications, FIFO, or the amount of memory on the block diagram
  Reduce the number of objects on the front panel
  Change the settings of the arbitration
  * Use Timed loops instead of other loops
  * Use Timed loops for intensive resources sections of the block diagram that
  do not require a loop

  I don't know how to solve this problem... Any idea?

  Thank you very much!
  Tom

  What happens if you did it in a loop For?  Two registers, one to accumulate the multiplications of the value of X, the other to accumulate the polynomial to offset additions.

• Multiplying by output of small polynomial coefficients on vi trendline and get unexpected results

  I'd appreciate it if someone could shine any light on this problem for me.

  I'm performing a polynomial regression with the VI express Curve Fitting.  The express VI itself works very well.  I used the polynomials it generates for the graph of a function in Excel and it looks perfect.

  When I convert the signal to an array and then multiply by other values things start to go south.

  The results of multiplications are wrong when some 'x' values are used.  The strange thing for me, is that it does not work for all values of x.

  Not sure if this is useful, but the expected values for x 0 through x 5 (bottom right, below) are:

  x 0:-1,14

  x 1: 16.11

  x 2:6-3-19

  x 3:-3.39E - 4

  x 4: 6.76E - 7

  X 5:-2.08e - 7

  and the values displayed when the routine is running:

  x 0:-1,14

  x 1: 16.11

  x 2: 25.57

  x 3:-925.06

  x 4: 104.25

  x 5:-2017.87

  Any ideas?  I think a data type must be changed since the expected values are very small and the problem is only present for certain values of x.

  If this is the case I don't know how to change the data type.  The table contains double the conversion of the shape of the signal.

  Thanks for any help,

  Dave

  

  Hi TCPlomp,

  I just realized that I had x and is reversed in my entries "power x" function.

  Thanks for letting me know about polynomial screws.  Add those who should be more pleasant than to try to clean it.

  Kind regards

  Dave

• function with a variable number of cubic curves

  Hello

  I have a set of data : a set representing the independent variable and a set representing the dependent variable. I need to find the minimum number of cubic curves (find their coefficients) that reduce the average quadratic error less than a given tolerance. If the tolerance is higher than 17 particular segments, so I need to raise an error.

  You have an idea what function blocks, I need to?

  I could use general polynomial Fit VI with order 3 and its default method to check the residue. If the residue is greater than the given tolerance, so I could try to use two cubic curves and test them on different starting and ending points until the residue is less than the given tolerance. If tolerance is not guaranteed, I add another curve and I test again the Assembly as shown above. By iteration until the residue is less than the given tolerance, or until I would need to add 18th cubic curve.

  If there was something ready, I would be grateful.

  Thank you.

  Fabiobonelli wrote:

  Please, you can test your VI adding another point to four present?

  X =-6453

  Y =-266

  Check the residue.

  Thank you.

  Did you even read my response? You have a serious air conditioning problem because the data is on a narrow Beach far from zero. By example-6500 ^ 3 is smaller that - 2E11, i.e. a value that many (many!) is orders of magnitude different from that of the constant term (1). The linear algebra problem that results is very ill, conditioned and just blindly Ford over the accelerator pedal are bad advice here.

  This isn't a problem with the implementation of LabVIEW, but a fundamental vice that you encouter also (or worse) If you would do your own math. No way around it. (See also)

  My recommendation is to delete the X offset and add it later again. Now things work correctly. (Note that a second order polynomial fitting still works without twist it).

  Try the and see for yourself.

• accuracy of polynomial roots

  Hi all

  Does anyone know the accuracy of the polynomial root function

  up to how many decimal places can I be sure of the result of the root?

  Best regards

  Tinnitus

  
  

• General polynomial fitting of a curve at 5 points

  Hi, I'm trying to adjust a curve of only 5 points with the polynomial general function, but it doesn't seem to work. I tried all the algorithms and controls up to 5 (number of points). You have a solution for that wonderfull should be that we get with excel?

  

  I think you're using the coefficients in the wrong order. If the coefficient is a, the formula is:

  y = a0 + a1 * x + a2 * x ^ 2 +...

  Or as you label, element 0 is e, item 1 is d...

  Hope this helps,

  Daniel

• Fitting with integral functions

  Hello

  I try to fit the data with full functions.  It is impossible to obtain analytical solutions of the integrations.

  Integration is integral [(T - abs [x]) f (x) dx, T, - T]

  Here, f (x) is one of the functions of autocorrelation for different model systems.

  Thank you

  Doogie

  Hi Doogie,

  We certainly have the integration and curve build VIs in LabVIEW. For example, you can find several kinds of system integrators in the mathematics > integration & differentiation palette. Also, if you use our design Simulation tools by & control, that built the integration as well. However, because you are dealing with an equation as opposed to sampled signals, I'd start by programming your equation in LabVIEW. Take a look at this forum thread that discusses this, and examples of code.

  Once you have programmed the equation and can generate an array of points for your stove, you might try to enter a function of integration as the "Integrate x (t) .vi" and then use a function as the "general polynomial Fit.vi" curve to generate an equation fitting for him. I would try getting started in this way. Please let me know if I address not the functionality that you are interested in.

  Best regards

• Calculation of adjustment of 3 Points 2nd order polynomial curve

  Hi all

  I wonder if there is a simple way to calculate the coefficients a, b and c in a 2nd order polynomial of the form equation

  y = ax ^ 2 + bx + c

  given 3 points known.

  Is there a LabVIEW function that can do this automatically?

  Thank you!

  -FB

  I think you're looking for a general Polynomial fit.

• Convert the function of transfer system model

  It is a practice "IF convert to transfer function of CDT.vi" in the system identification toolkit, but is a VI to go the other way? I used the id of system tools to estimate the TF from my system, but I want to compare it to the base of the first order response of the system to my real stimulus data.

  I can build a first TF command using the 'create order 1 model.vi CD' but I don't know how do to then turn this into a model of continuous system in which I can plug my real data.

  I am able to build a model system using 'IF create system model.vi' but it is a polynomial model, if there is a way to cajole this in the form of an order of 1st exponential base, it would be a great solution as well.

  (I'm experienced with LV, but my theory of control is rusty and I am totally new to CD modules and IF - then I apologize if this is a silly question)

  Hello

  You can use IF partially known continuous transfer (1st order) .vi model function and IF partially assess continuous known model transfer function (1st order SISO) .vi to estimate a 1st order TF, in which the parameters are defined as in CD create 1st order Model.vi