Interpolation of table

Similar Questions

• How to find the crest of a curve of best polynomial form

  Hello

  I'm relatively new to Labview.  I need to find the value of x corresponding to the maximum value of a better curve adjusted to a set of values there.

  A typical dataset that I will work with is a table of about 15-30 y-values that are equal distance from known x-values (I have attached a file .lvm for an example of values y and x values), and it will be a fairly well-defined Summit.

  The way that I do currently is to use the curve express vi, with a polynomial curve of 10 order, and then by converting the best adjustment line to an array of values using array Max vi Index to find the peak value y and wiring its index in a table of x values to find the position corresponding to the peak. I enclose my vi that does this.

  The problem with this method is that I can't get the accuracy I need (because the values of x are spaced by 0.15, I wish that the precision of about 0.01).

  I also tried out the best integrate a node formula coefficients (from the curve express vi) and then run a loop of x than aircraft values more accurate data points, but I had trouble getting the curve of this method to match the better to express vi curve curve.

  Do you have any suggestions?

  Call it what you want, but you're smoothing or filtering your data.  It will pass the height and location of your apparent peak.  Instead of trying to fit all of the data, you must use a mobile window where you set a subset of the points to a polynomial and check for a pic.  That's exactly what the Ridge detector VI.  I'd like to see if this VI - what are looking for before you go through the gymnastics of the polynomial.  In my example, I remove the maximum amplitude peak and find its location.  The location returned by the peak detector is a fractional index, so you can use interpolation 1 table D to find the corresponding x position.  If you stay with the polynomial in the form, discover all of the polynomials screws, they are a snap to find the zeros of the derivative and other.

  

  BTW, unless you really know the underlying model for your data I personally would be questionable estimates of precision that are 1/15th of the point spacing. 1/3 or 0.05 he pushes IMO.

  Edit: 1 K apparently.

• Time dilation of a curve with interpolation table 1 d?

  Greetings,

  I'm trying to run a time dilation of a curve I used to work with the table 1 d of function interpolate VI. Basically, I have to perform the expansion on each segment, that is why each segment contains 100 points, where there are currently 60.

  I am currently working with two files (the two are broken) to compare because I'm not sure how to use the table 1 d interpolating VI, and what I have to enter for the fractional index. I know that the output of the table in the first for loop should go in the 1 d array interpolated somehow.

  I'm stuck!

  Thank you!

  TheLT

  I'm good I thought it

  Here's how to do it for later use.

  Code attached.

  TheLT

• How to combine two tables: table of origin and its values of interpolation table

  We get a new array of values after using the interpolation on a table function in labview, but how to combine the array of values and this original interpolated set of values in a single table?

  
  

• How to make the waveform table rows less laeti WITHOUT using a lot of mathematics of interpolation

  

  So I use a graph shaped wave, the numbers of entries sequence like that, sensor 22,23,24,25... the graph seems laeti. (Fussy) client says hey I want a good graph, you have function spline or something?

  So I was to research the properties of chart and saw the settings below that does not help much. I proposed to the customer (picky) that Hey maybe we can make the balance Y greater for the lines of the stairs will be not so obvious, the customer (picky) says no. So I was sweating on tedious mathematics required for interpolation in the hot oil and noisy, without internet, fortunately the dinner bell rang.

  Now is there some function blocks which makes the table lines smooter, a function spline or something? Thank you.

  
  

• Apply tweens to objects in a table: stuck interpolations

  I am applying interpolation for each element in a table (it's all just an experience...) I'm trying to learn more about tweens). The problem I encounter is that most of the time, tweens begin to play but then all the tweens stop except on one of the bubbles.

  Sometimes they end and a finish is more likely when numBubbles is set to a low number such as 5 to 10. This would be a limit of tween problem? I don't have to understand that to be likely.

  Here is my code:

  import flash.events.Event

  import fl.transitions.TweenEvent

  import flash.events.MouseEvent;

  import flash.utils.Dictionary;

  import flash.display.MovieClip;

  Import fl.transitions.Tween;

  Fl.transitions.easing import. *;

  Import fl.motion.Color;

  bubbles var: Array = [];

  var numBubbles:int = 55;

  for (var i: Number = 0; i < = numBubbles-1; i ++) {}

  Bubbles.push (new bubble());

  stage.addChild (bubbles [i]);

  startMotion (bubbles [i]);

  }

  function startMotion (TheBubble:bubble) {}

  var tweenY:Tween = new Tween (TheBubble "y", Regular.easeIn, TheBubble.y, -5, 3, true);

  }

  The bubble that continues to go isn't the first bubble of the matrix or the last. It seems to be random (a little). One color makes sometimes--most of the time it's one of the others.

  Oh, and here's the bubble class:

  package {}

  import flash.display.MovieClip;

  import flash.events.Event;

  Import fl.transitions.Tween;

  Fl.transitions.easing import. *;

  public class bubble extends MovieClip {}

  var bubbleSize:int;

  public void bubble() {}

  this.bubbleSize = Math.ceil (Math.random () * 15) + 15;

  This.Width = bubbleSize;

  This.Height = bubbleSize;

  This.x = Math.random () *(550-bubbleSize);

  This.y = 400 + Math.random () * 400;

  }

  }

  }

  I would appreciate any help or insight!

  and then they always receive gc had.  use:

  import flash.events.Event

  import fl.transitions.TweenEvent

  import flash.events.MouseEvent;

  import flash.utils.Dictionary;

  import flash.display.MovieClip;

  Import fl.transitions.Tween;

  Fl.transitions.easing import. *;

  Import fl.motion.Color;

  bubbles var: Array = [];

  var numBubbles:int = 55;

  var tweenY:Tween;

  var tweenA:Array;
  

  for (var i: Number = 0; i<>

  Bubbles.push (new bubble());

  stage.addChild (bubbles [i]);

  startMotion (bubbles [i]);

  }

  function startMotion (TheBubble:bubble) {}

  tweenY = new Tween (TheBubble "y", Regular.easeIn, TheBubble.y, -5, 3, true);

  tweenA.push (tweenY);

  }

• Expand 32 table of entry to 1024 by interpolation

  
  

  I agree with RavensFan.

  If you want to do a brute force method, consider using the Pattern.vi ramp inside a loop.

  Lynn

• interpolate table 1 d

  Is it comes to table interpolation works according to the interpolation formula before Newton-Gregory. As I don't get exact value next to programming.kindly in the attached photo for reference... According to the formula I get 214.6875... but using the programming I get 231,5... can someone help me

  It's a very elementary algebra, linear interpolation.

  For a X between x 0 and X 1, you get the value of Y = Y0 + (Y1 - Y0) *(X-X0) /(X1-X0)

• Table data collection and using other calculations

  Hi all!

  I have a table with the information (values), I want to read and collect the 4 values in the table. These must serve more than calculations.

  Take a scenario:
  Let's say the row index is 2.5 and the column index is 5.6 (these values are other calculations), so I'd like to collect the values of the matrix, return (2.5) (2.6) (3.5) and (3.6). Thus, in the closest base to the index value of two integers.

  The next step is to use these four values make a bilinear interpolation (that's my problem), but in order to use them, I need to get them into a knot of formula.

  To sum up; How to collect and store the 4 values for further calculations.

  I hope I explained good enough!

  PS! I'm rather new on LabVIEW, love until now

  Sounds like what you are really looking for is 2D.vi interpolate. Check it out on the range of mathematics under the Interpolation.

  Or you use another type of interpolation function?

  No need to reinvent the wheel if your 2D table represents just the nodes on a surface.

• Count the number of rising edges in table 1 d

  Hello

  I wanted to measure the frequency of a pulse signal using a MCC DAQ via libraries ULx in Labview. I have two methods to do this:

  1. use the analog inputs:

  Since data acquisition has only 1 ADC, I use a commune VI acquisition for all channels and create a multi-dimensional array with different channels in rows 0-15. Then divide them by using the function "Array Index".  I think this split removes the parameter 'time' to the wave, since it is now a table 1 d. But I already know that there will be 1000 samples each 100 m everything I want to do now is to count rising edges using a function and divide it by the 0.1 to obtain the frequency in Hz, but I don't know how. Can anyone help?

  2. use the input frequency meter:

  Because I can't use the DAQ assistant, I have to use the CI frequency-> counter 1ChanNSamp DBL 1 d in the ULx library. There is no reference to take aid to and I do not know if this method is good. I have no way of knowing since I do not have a signal generator. In addition, it does not work so far.

  Help, please.

  Thank you!

  Thank you.

  I note in your first post it is seems to want to get readings of speed about 10 times per second. To get a resolution of 1 Hz frequency direct count you need to get at least 2500 counts in a range of counting at the highest frequency. This means that you need to have at least a second. Measures of the time are another option.

  Some preliminary calculations:

  Period at 2500 RPM = 2500 Hz is 400,000 Americans.

  Period at 2499 RPM = 2499 Hz is 400,160 to the United States.

  You need to be able to resolve a difference of 160 ns period. To do this directly requires 6.25 MHz sampling rate.  It is 25 times faster that your DAQ card can enjoy.

  What other options are there? Consider only your Information.vi extract. He uses techniques of Fourier transformation and interpolation to find the frequency of a signal. I set up a quick test VI to check this. Using a sampling rate of 10 kech. / s and 1000 samples per read (10 reads per second), it has easily resolution of less than 0.1 Hz at both ends of the range of speed and largely independent of the amplitude.  This is the way to go.

  Lynn

• Interpolation - more than one point

  Hello

  I'm trying to find the position that a graph crosses the x-axis zero. The problem is that this happens several times in my chart (this is a graph of the reactance of a parcel of impedance). I use 1 d interpolation and it returns only one point of intersection instead of 2-3 that occur. Is it possible to get all three?

  Any help would be greatly appreciated,

  Bill

  Typically when you need to detect multiple instances of a condition in a data table, you will find the first and then look for the part of the table after the first to the second.  You probably won't find a built-in function that will do this for you. The process I described in my previous post will be repeated.

  Lynn

• split a table 2D to 1 d by row tables

  Hello

  I'm doing 2 things with tables and their dimensions. They both seem pretty basic, but I can't figure out how to make...

  1 table split a 2D of size 2 x N in two tables 1 d of length N.

  2 reshape an array size 2D m x n in a table 1 d of length mn, then do the reverse procedure and recover from a 2D m x n table. (After doing some manipulations, interpolation, etc.).

  Thank you!

  1 index Array.

  2. table of remodel.  However, you will probably need to consider the size of the array and do a little math to supply the values of the array function to reshape.

• Pick up the front of the table

  Hello

  I have a lookup table which uses the interpolation method to get additional results.  It is possible to sort the values in the front panel to power this lookup table.  I would be for the user to enter the values to the front and not in the search in the block schema properties.

  Thank you

  
  

• How do a look up table in labview?

  What is the best way to make a glance toward the top of the table for a dozen of values?

  Would be to make a Tween equation require much more processing power?

  I agree with the previous post of the use of the attributes of variant for string searches. There is also the function "Interpolate 1 D Array" that might be what you are looking for because if you have sorted is the data you want to interpolate. If you have X of the data that you want to search, you can use the 'threshold 1 table d' together with the interpolation function. See picture attached for example.

• Addition of waveform with adding block - element wise or interpolated or...?

  Hello

  I see the block addition is beautifully overloaded to overlay waveforms and I would like to know how it works. Specifically, I want to know if using matrix addition (i.e. simply by adding the elements of each waveform) OR is he among the waveforms by interpolation and resampling to the points of time corresponding to the other or another method.

  I know that the sampling interval (dt) should be the same for both waveforms added, so I suspect it is using matrix addition, but don't know.

  To add a bit of context, I use this to add two waveforms of sampled data of a sinus waves up to 100 kHz. Sampling faster than my DAQ can exploit the difference in the two waveforms of departure time (t0) is an important part of the period. At this point, I think that the approach by adding simple matrix will not work.

  Thanks for any idea that you can give. See you soon

  -ron

  Hi Ron,

  I don't think there is a VI that does it for you. However, it should not be too difficult to program yourself. There's a Subvi, called 'Get waveform components' that allows you to access the table variables (Y) t0, dt and the data type of waveform data. You can subtract the two start times to find the difference between the two waveforms (DAQ readings put a timestamp on the data). Then you can complete the table operations to create a lag in the data. A few other useful subvis are "Get the subset of waveform" or "Index Waveform Array", you can use depending on how you want to set up your program. Let me know if you need help with this programming. Good luck!