Similar Questions

• limitation of exponential Assembly

  Hello

  I have some difficulty tio adjust an exponential curve. For example: linear VI, Exp and mounting of power (in labview\examples\math\curvefit.llb) and parameters:

  -number of points: 3000

  r: 1E-9

  b:-0.0006

  -c: 1

  - and no noise

  

  The results are not really what I expected. No idea why it does not work or what other solution could be used?

  Thanks in advance

  EXT on 18-21 decimal digits (mantissa is 64-bit) Windows, will not give you 34 as falsely claimed above. This will really help you save if rewrite you anything that is used within the hierarchy of the whole fitting. Even if you do, there will be limits.

  The real problem is that your data causes internal matrices become ill-conditioned. The condition number is greater than 1E19, making it impossible to determine improved parameters. (Because you'd lose > 19 digits of precision, same EXT is not sufficient).

  You need to scale your data in a range more resonable, then transform found adjustment parameters for the original values. For example, if you set c = 0 in the adjustment and also to change the condition of termination to a much smaller value (e.g., tolerance = 1e-14), successor to the adjustment.

  If you have real data, subtract a constant adapted according to the data for editing (for example, the value of the last item), then add it to the C found later.

• exponential response moving average stage fpga

  Hey guys,.

  I have a problem with my filter, the exponential weighted moving average filter (IIR 1 st order.). Excerpt from the book: understand the digital signal processing (Richard Lyons) I have the following formula, calculate the frequency of 3dB (CF) of alpha. Alpha is the parameter to control the filter.

  Differential equation of the filter: y [n] = x [n] * alpha + (1 - alpha) * y [n-1]

  Relationship between CF and alpha: alpha = cos(2fc/fs) - 1 + sqrt [cos²(2fc/fs) - 4 * cos(2fc/fs) + 3]

  If I now choose a frequency of 3 dB from 0, 0794Hz (time constant (TC) = 2 s) alpha = 0,00169621. (fs = 94)

  For a filter command 1st IIR, the rise time (your) of the stepresponse (from 10% to 90%) is: ta = 2, 2 * TC which translates your = 4, 4S.

  But if I simulate the step response, my rise time is about 3 times this value at 14.

  I can't explain why the response of my filter is so much different. For my Moving Average filter, the calculated and simulated rise time are equal.

  I have the vi that is performed on the attached FPGA. Maybe someone can find a mistake...

  Greetz

  Slev1n

  Hey ZX81.

  Thank you very much for your detailed answer.

  Regarding the issue with the rise time, I think I've found the error. You might be right, that the formula is not correct, or which is most probably misunderstood by me and put in the wrong context.

  When I was cycling home from work I remembered a practical function of labview: 'coefficients.vi filter smoothing' here you only need to define tau/TC and fs and it calculates the numerator and the denominator for the moving average exponential and the moving average. Offering it is alpha I could compare the result of the formula I've used and there was a big difference. LabVIEW uses the following formula: alpha = 1 - exp (-1 /(fs*TC)). With this formula, TC = 2 s is equal to alpha = 0, 0053.

  And with this alpha my simulation works! Risetime 4.4 s

  Quote you: "in general, at this stage, I have maturities adjust alpha until my results matching what I wanted and move." I would like to do the same thing, but as it's my thesis I have to solve such things

  Now, back to the rounded questions. I understand that the small values are a more serious problem. This filter is used in a Lock In, the values are going to be REALLY small. But I've already tested on our measuring device and it works, to that effect, I'll test your version as well, but if I get no problems, I guess I keep to the 40bits. Simulating the following configuration, caused an error of 2.3%. 57 bits using reduced the error less than 1%. I think that 40bits should be sufficient.

  Alpha = 0, 000335693

  entry = 1, 19209E-7

  And regarding resources, I have no worries. Although using a myrio ultimately I still have a lot of DSP Slices for the multiplication and 10% in flip flops.

  So I guess that this matter is resolved. Thanks for your great help and interesting reflections.

  Kind regards

  Slev1n

• VI LabView 2014 exponential Fit does not return an offset

  Hello world

  I use LabView2014 and that you want to adjust an exponential curve as A * exp (B * x) + C with VI 'exponential Fit'. In all cases, the VI returns C = 0 and attempts to correct this error by using the bad A and B, which of course gives bad results. Any ideas? I have attached my VI.

  Thanks in advance,

  Aaronski

  You must give a better estimate for the parameters of adjustment or to give a tighter tolerance.

  Right now the default on the maximum offset is set to zero, and your tolerance is set to 0.0001. When you arrive at the large exponential, the algorithm stops because it meets the tolerance soon enough.

  EDIT: Try to reduce your ramp so that you use not e ^ 100 in your editing. For numbers that big, even using epsilon machine as tolerance will result in satisfactory adjustment of tolerance with a pretty crude pass. You can also try to reduce the weight of the extremely large numbers of adjustment.

• Fit.VI exponential fits well

  Any attempt to use the "exponential" Fit.vi to find the time constant the time of settling so that loop of PID parameters can be calculated from these data of open loop is attached. The orange line is the data, I'm trying to adapt. The blue lines is the exponential fitted with "Fit.vi" data output These data are the temperature difference between a thermoelectric cooler element in response to a radical change in the current. I know that the answer will be not exactly exponential because this response is actually the sum of many exponential as the heat is different paths. But all I need is a rough idea of the time constant of the rise of dominant, and that will be good enough.

  There are four fits that begin when each step response begins. The outcome of each adjustment is far away. The adjustment does not start at the same temperature the step response is. And the curvature is the inverse of the adjusted data. What could be wrong here? Is there a better vi to use to get this exponential time constant?

  I use the default settings for all entries to 'exponential Fit.vi.

  Your data has a big lag, so you must make sure that the offset is not fixed (by default, it is set to zero!). Change the third parameter limits to [-inf... + inf] and the rest will fall into place.

  

• Estimate of exponential decay time constant - taking tangent lines

  Hello

  How would you estimate a first order decay time constant? I have a system that loses heat very slowly and I wish assess the time constant of the first part of the data in order to allow more frequent tests (I know it will end by decomposing to).

  I know I can make a good estimate based on the initial slope of the curve, but I don't know how to implement this in LabVIEW. Does anyone know how I can make the VI calculate a tangent line to a graph, and to find where it crosses another line?

   

  
  Thank you

  How about using the

  VI exponential form

  Have the Palette: Screw

  Request: Full development system

  Returns the exponential fit to a set of data (X, Y) using the method of least squares, less absolute residual or Bisquare.

  This VI uses the General iterative least squares method and the method of Levenberg-Marquardt to adjust the data to a curve exponential of the General form described by the following equation:

  f = ae^bx + c

  where x is the input sequence X, a is the amplitude, b is depreciationand c is out of step. This VI find the values of a, b, and c that better observations (X, Y).

• Auto micro adjusts the input level

  Hi all

  I tried this several times and never seem to be able to find an answer that works...  When I talk in my microphone on my macbook pro, it adjusts permanently the input levels, so in mid-sentence volume varies (always at peak).  It is extremely annoying, and there seems no obvious way to a certain volume of recording.  Any help here?

  Thank you!

  Hi Aprilstern,

  I understand that the input of your Mac's built-in microphone volume seems to be fluctuating when you save. In this case, if you use Mac OS X Yosemite or earlier, you may want to turn off noise reduction in system preferences > Sound > entry.

  OS X Yosemite: adjust the settings of your computer's audio input

  Kind regards.

• How to adjust the number of rings on 6s before answering iPhone begins

  How to adjust the number of rings on iPhone 6s before the beginning of voicemail?

  Contact your operator. That is controlled by them. It is not based on the number of rings, it is based on time.

• Adjust the brightness of the keyboard of the computer instead of the keyboard?

  Yesterday, I spilled some coffee on my keyboard and the computer works well, but my keyboard does not work.  I bought a wireless keyboard to use and it works perfectly, except that the keyboard of my laptop backlight is always on.  I can't figure out how to turn off without using the f5 and f6, keys that don't work on the laptop, so how can I disable this light without using the keyboard?  F5 and f6 don't work on the original keyboard at all, and on the outside, they do not work to adjust the brightness.

  Try this:

  Go to system-> keyboard Preferences, and in the keyboard tab, disable(uncheck) automatically "illuminate the keyboard in the dark.

• How can I make the adjustable text size in iBooks author?

  I use iBooks author (2.4.1) on an iMac (end of 2015), El Capitan (10.11.6) running. I would like to know if there is a way for the size of the font to be adjustable using the toolbar at the top of the screen in the iBook resulting?

  Thank you!

  Hello

  I had trouble with this question, too, as I began to use iBooks author earlier. From what I've learned, the ability to offer adjustable fonts for the reader / end-user is based on the original model that we built our book on. But there is more that we have the choice in versions of model e-pub and multi-touch included those with iBA. I'm building a Multi Touch iBook which is based on the iBA model included for the landscape layout - there is no support in this one for the reader change the font. I found that for me, I had to choose between: fixed layout, content can be layout and multi-touch (exclusive iBooks). Given that the multi-touch functionality is very important for me because my iBook project a lot of nested widgets Gallery, lack of adjustable characters was acceptable (to me).

  I know there are items online somewhere at Apple, but I couldn't find them easily. I found another article that can help you:

  http://ebookarchitects.com/Learn-about-ebooks/non-fiction-fixed-layout/

  Best regards and don't give up ;-)

• Airport Extreme is adjustable upward in client mode?

  I've set up the Express in client mode before, but I'll have set up extreme. During setting up he sees that I am on an existing network, but he doesn't know that and wonder if I would create a new. When I try to connect to an existing network, it indicates that an unexpected error has occurred. I also tried to set up a new network and then in the utility existing Airport to connect to the network. He takes the password and restarts and then never reappears in Airport utility, after I switch back to the existing network.

  AirPort Extreme is adjustable upward in client mode?

  No, do not use any version 6.x of AirPort Utility.

  Maybe, if you have an old 'flat or square' in the form of AirPort Extreme and you can use an older version 5.x of AirPort Utility to maybe put in place.

  But even if you could do that, the extreme doesn't really matter in client mode. The Ethernet ports are not enabled, and the extreme would not "extend" or "repetition" of the network. The only thing that would work would be the USB port, which runs at half the speed of a USB 2.0 standard.

• How to set the pressure necessary for the keys on the keyboard? I adjusted it 2 years when I had my Macbook Air, but I forgot how I did it. In my opinion, only a touch of F has been used.

  How to address the need to pressure for keys? I've adjusted it 2 years ago when I got my Macbook, but I forgot how. In my opinion, only a touch of F has been used.

  I don't know what you are referring. You can't 'adjust the need to pressure for the keys. The keyboard is what it is. The key must be pressed far enough for electric contact in key switches. The keys are not adjustable in this way.

• Plain text email entry keeps wrapping the lines too short and I can't find a way to adjust the length of the line.

  It doesn't seem to be a way to adjust the position in which the lines get shortened. OK, there is a menu item "Wrap", but if the lines are already too short or too long.

  Try to paste the terminal output lines in an email looks like lame because of unwanted packaging.

  Look for this setting in the configuration editor

  Mailnews.wraplength; 72

• adjust frame numbers 3.6.2

  I'm under 3.6.2 numbers on my Mac with El Capitan.

  I want to adjust the exposure of some of the images of certain cells.

  I found this Apple info below, but there is NO Picture tab.

  I found a picture tab to set under VIEW, but it is grayed out.  Can I get a picture in there.

  Any suggestions?

  Adjust exposure, saturation and other parameters of the image

  1. Select the image, and then click the tab of the Image at the top of the sidebar on the right. If you do not see a sidebar or sidebar is not an Image tab, click on in the toolbar.
  2. Use the buttons to make adjustments:
     • Exhibition: Changes the brightness or darkness of the totality of the picture.
     • Saturation: Changes the richness of the color in the image. Dragging to the right makes the colors richer or more dynamic.
     • Improve: Automatically adjusts the image by spreading the tones of red, green and blue evenly on the histogram.

  Although number, you must select an image that is part of a numbers document in order for the contextual trainers to be filled.

• iMovie 10.1.2 adjust the size of the clip in the timeline

  When I move a clip in the timeline, the size is reduced to a point where I can't move titles correctly.  I tried the setting of the slider, but it does not affect the components of the package.

  Hi, David,.

  You use the scroll bar that you get when you click the gear in the top middle of your screen.  This bar only works on clips in the clips pane, not in the time line.

  The slider beside the button settings in the middle right side of your screen expands the time line so that the clips in it are spread out more.

  Also, if you click on the settings button, a dialog box appears that contains a scroll bar to adjust the size of the clip in the timeline.

  Hope this helps,

  -Rich