Gaussian plot

Hi!
Need help to calculate FWHM (full width at half maximu) from sineformdata. I am using labview 7.1 so there is no gaussian fit function in that version. Please take a look at my code where my data is an array and waveform graph. Goal is to chage signal to look like gaussian and then calculate FWHM.
Data included in vi
Please help
Attachments:
Data.vi ‏22 KB

I assume you are trying to find a gaussian ditribution function to fit to the data. All you need is to find the average and the sample standard deviation of your data and then build the Gaussian function. You can plot that, you can also plot a histogram of your data to compare to the Gaussian plot.
With little programming code, you should be able to do that.

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Fitting a Gaussian curve onto a set of data

I'm looking to plot a best fit Gaussian curve unto a set of data and was wondering if this is possible with just the labview 7 base development software. Any help would be greatly appreciated

I assume you are trying to find a gaussian ditribution function to fit to the data. All you need is to find the average and the sample standard deviation of your data and then build the Gaussian function. You can plot that, you can also plot a histogram of your data to compare to the Gaussian plot.
With little programming code, you should be able to do that.

Best fit curve (gaussian)

I am having an issue implementing the gaussian best fit line on the data in the attached vi. How can i get this done?
Will appreciate any help!
-FredFred
Attachments:
best fitvi.vi ‏58 KB

FredFred,
I think I've found a great example that shows how to use the LevMar.vi. It can be found here. It also shows how to plot the data from the LevMar.vi to gain the result I think you're looking for. Post if you have further questions.
Best Regards,
Chris C
Applications Engineering
National Instruments
Chris Cilino
National Instruments
LabVIEW Product Marketing Manager
Certified LabVIEW Architect

Gaussian Peak Fit and Nonlinear Curve Fit on small data differ from Origin Peak fit

Hi all,
I am developing a program in which I have to fit Gaussian curve on only 4 or 5 data points. When I am using Gaussian Peak Fit or Nonlinear Curve fit, it linearly connects all the points while other fitting software like Origin is fitting Gaussian curve on the same set of data I have attached two images One is from Labview with Gaussian Peak Fit and NonLinear Fit and other is from Origin.
Data is
X                       Y
799.09857      257
912.25256      641
1026.00366   1516
1137.92871   1118
1253.43713   329
Labview user
Solved!
Go to Solution.
Attachments:
Origin_Fit.PNG ‏21 KB
Labview_fit.PNG ‏15 KB

That looks like a plot of the input data.
When I run it with your data I get a Gaussian curve which looks much like your Origin plot.
The Plot 2 curve is from 128 points equally spaced along X and Y calculated from the Gaussian formula in the LV help using the output parameters from the fit. Plot 1 is the Best Gaussian Fit output from the fit VI. It only has five points.
I used default values for everything except X and Y.
Lynn

Can someone verify my code for calculating a Gaussian kernel?

I've attached my VI for calculating a Gausssian kernel function of selectable width and resolution. I am not an expert in mathmatics and I was hoping someone on here could confirm the validity of my code. If anyone has any suggestions please let me know.
Eric
Attachments:
Old Gaussian Kernel.vi ‏24 KB

To better show what it is I'm trying to accomplish, I've attached
the top level VI that's using the kernel function, entitled "Pattern
Analysis of IPIs 2," . The zip folder contains the top level VI, a
folder with all the subVI's and two data files. Open the "Pattern
Analysis of IPIs 2" VI and go to the "Files" selector tab toward the
bottom right of the front panel. Here you'll be able to select the
folder containing the data files. You'll need to unzip the attached
folder and save it somewhere, then select that folder as the "current
folder" to be opened (you don't need to specify which data file to
open, it will open both). Once the folder is selected you can run the
VI and view its results.
When the program begins
running a boolean indicator located in the bottom left corner will
appear red and the slider bars along the bottom will be disabled. When
everything has been calculated the boolean will turn green and the
slider bars will become enabled. Choose the selector tab entitled "SPI,
SDF & SDD" to view the spike density function. The spike density
function (SDF) is what's being created with the Gaussian kernel. The
enabled slider bars allow you to adjust the x-axis values of the plot.
The cursors on the plot indicate indicate the start, peak and end of
high rate bursts. It may be easier to visualize this by viewing the
raw data located at the "Wfm Absolute and Relative Time" selector tab.
To reduce file sizes the raw data has areas of "quite" removed, so you
will only see the voltage change events, represented by what appear to
be vertical lines.
To move to the next data file, click
the button entitled "Save and Go to Next" located in the bottom right
hand corner. A prompt will appear asking if you want to save the data,
click "No" and the next file will automatically be loaded. To stop the
VI, wait until the boolean is green and the slider bars are enabled,
then click the "Stop" bottom located at the bottom right. It may take
a few seconds for the VI to stop.
Moving to the
block diagram, you'll see a yellow subVI with black writing that says
"SDF," this is where the SDF is calculated. Open the front panel and
block diagram of this subVI. On the block diagram you'll see the subVI
entitled "Gaussian Kernel," this is the subVI you saw yesterday. The
generated Gaussian kernel is alligned at peak pulse times (can be seen
in the graph entitled "Gaussian Kernel Alligned at Peak Times") and
summed to create the SDF. I only choose this method of generating the
SDF because it seemed intuitive to me, it may be wrong. If it is,
could you please demonstrate how to program the convolution.
Ultimately, I'm trying to achieve the plot described on the third page
of the attached paper.
Attachments:
Pattern Analysis.zip ‏2916 KB
Stereotyped temporal patterns in electrical communication.pdf ‏380 KB

Fitting multiple gaussians to curve

Hi,
I'm collecting a data array and saving it to a spread sheet. I can plot this on an xy graph however in order to process the data i need to separate the curve into separate gaussians. In theory decimating the curve should do what i need but I can't figure out how to make this work. Can i do this using point by point, or is there a way of converting each line into a wave to process it in this way?
The attached files are the basic vi that im using to read the saved file and an example file. I haven't included any of the errors as i've made as they haven't worked. I hae tried a simple guassian fit but as the peaks are overlaid on each other it isn't working and i feel sure that theres a better way of doing it than multiple iterations of this, particularly as the number of peaks varies.
Thanks!
Attachments:
cut analysis 2010.vi ‏73 KB
selected spectrums.xls ‏848 KB

Hello and thanks for using the forums.
If I understand your query correctly, you would like to be able to split your data into separate plot instances on the same XY graph in the simplist way possible. I have attached an altered version of your VI which will plot each gaussian separately.
If I've misunderstood your query please feel free to provide some further clarification.
Kind Regards,
Paul
http://www.paulharris.engineering
Attachments:
Separate Gaussians.vi ‏62 KB

How to add a gaussian curve on a histogram chart.

I want to add a gaussian curve on the histogram chart like the attached picture. I plot the histogram already with my data, but I don't know how to add the gaussian curve.
I appreciate your help very much.
Solved!
Go to Solution.
Attachments:
histogram_dis.JPG ‏37 KB

If you have the Statistical Process Control (SPC) toolkit or Datalogging and Supervisory Control toolkit (DSC), LabVIEW has many built-in histogram functions.
look for "Plot Histogram and Normal PDF"
Attachments:
histo.JPG ‏76 KB

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I am writing a little curve fitting utility to post-process some data. The user inputs a file, part of which is turned into a histogram, and then the user identifies peaks on the graph and Labview fits and plots a gaussian at each identified peak. For some reason, the log plot output seems to be rounding to integers, which leads to ugly blocky graphs, as you can see if you run the .vi as described below.
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To get the example plot:
Run the .vi and feed it the .csv file
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click on the graph at the 3 peak locations (roughly (0,20), (1200,8) and (1500,3))

woops, forgot to include that one. It is attached. I found the problem, though. Casting the output of the General_Histogram.vi to double fixed the problem. Apparently if you wire integers into the fitting program it outputs a rounded fit, for some reason. Seems like a bad choice of default behavior, since it involves a loss of precision...

Live plotting of contour from camera acquisition: best strategy ?

Hi every one,
I am trying to create a VI to acquire images from a camera (Basler scout). Among the features I need to implement, one is the live plotting of the contour of the gray scale values to enhance their visibility (I am then using it to tune a light source into a centered gaussian distribution).
My issue here is that the images are too big and the whole VI lags, with a new plot appearing every 3 to 5 seconds, which is too long. A constraint is that I must be able to record pictures with full resolution.
Enclosed are 2 easy examples, one using labview only and the other using Matlab to decimate the number of pixels, and a typical result. Both performs similarly, i.e. too slowly.
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Hope you can help me,
Best regards,
GL
Solved!
Go to Solution.
Attachments:
VIplot2.vi ‏49 KB
VIplot.vi ‏17 KB
example.jpg ‏36 KB

Stephan,
Here is a picture from the camera.
The camera is a Basler scout 1400 17gm with gige interface (http://www.baslerweb.com/en/products/area-scan-cameras/scout/sca1400-17gm), picturing at 1392x1040 pixels.
Hope it helps !
Best,
Gael
Attachments:
lamptest10.png ‏257 KB

How can I represent more than one plot in an only one chart?

Hello everyone,
i got a code where I don't understand how to represent more than two plots, with different scales each, in the same waveform chart.
As brief review:
* 2 adquisition data wired to Bundle
* wire from Bundle to waveform chart.
* options of th chart: stack plots.
I've tried to expand the Bundle but the problem is that I'm wiring a 3 element cluster to a 2element cluster chart. I don't understand how to upgrade the chart...
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Marcelo A J

Since you are dealing with waveforms already, I think you actually want to have an array of waveforms to go into your chart. You also need to map the plots to the scale that you want to use. You can do that in the plot tab of the properties window.
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How to get lab view to display my plot in DB

hi guys
i desigED n an operational amplifier to determine the gain product band width using a 741 chip and the gain of the circuit is 1000, meaning that the gain bandwidth PRODUCT will occur at a frequency of 100hz. but i have a problem, when i start the frequency sweep from the function generator from 10 hz to 100Khz which IS the final frequency value i have set for the program. when the lab view program stops and i export the data to excel sheet i will be getting the DB axis value in a SMALL VALUES AND IN DIFFERENT UNITES WHEN I PLOT THE GRAPH USING EXCEL, while the frequency is in log10.
pls can any one tell me how to solve this problem to start getting the right cut off frquency on the graph. find aattched my vi and the excel data from the vi that is in a different unit not in DB
Attachments:
GAIN BAND WIDTH PRODUCT.vi ‏116 KB
FREQUENCY VALUE .xls ‏26 KB

Ahhh.....
emeho wrote:
thanks Jeff Bohrer for your reply, what i mean is the y-axs of the plot is in DB aleady, but when i export the data to excel i will be seeing the gain in 0.8, 0.7,0.4 which is not normal, which will not give me the -3db point of the gainband width product of the circuit
What you want to do is plot the Log(10) of the frequency on a linear axis!!!!!!! The export - exports the values not the axis scale. exporting a log(10) of the Y axis will export the log of the axis- (of couse, you could change the graph axis scale in Excel too...... but)
Jeff

How to Plot number and string in one row (data logger counter via MODBUS) ?

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Attachments:
MODBUS LIB Counter.vi ‏39 KB

Hi rhiesnand,
right now you add 2 new rows to your array.
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How to Plot number and string in one row (data logger counter) ?

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Attachments:
MODBUS LIB Counter.vi ‏39 KB

Duplicate and answered - http://forums.ni.com/t5/LabVIEW/How-to-Plot-number-and-string-in-one-row-data-logger-counter-via/m-p...

How to let the user define the colors for each plots in the graph (I use LabVIEW 7)?

How to let the user define the colors for each plots in the graph (I
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Hi,
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Changing_plot_color.vi ‏38 KB

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Gaussian plot

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