Coordinates of intersection of waveform

i have two arrays plotted on the same graph. I am looking for the coordinates where these two graphs intersect. The information about the exact graph is given in the attached VI.
thanks a lot for your help. I have a feeling that this is quite trivial but would really appreciate any help.
Attachments:
find intersection.vi ‏83 KB

an easy method is to find the shortest distance between the array points |Ya-Yb|. The closest value will give you an approximation (assuming the waveforms share a T0 and dT). You can speed this up with a binary search. This assumes that the graphs have one and only one intersection. Interpolation can give you a more exact value. Sloving the functions for the forms also will give you an answer assuming that you have the functions defining the curves (through curve fitting)
Paul Falkenstein
Coleman Technologies Inc.
CLA, CPI, AIA-Vision
Labview 4.0- 2013, RT, Vision, FPGA

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so, i have a project for a class, and for that project, i have to read the coordinates on the waveform chart.
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Attachments:
coordinate XY.vi ‏40 KB

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Hi All, hope everyone is having a wonderful 4th of July.
Alright, so I am new to labview and finding my things around the simple things pretty well, but having never taken any sort of programming interest, Im a bit behind in machine logic, so I figured I would ask here.
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The research I am doing involves analyzing Electron Speckle Pattern Interferometry (ESPI) images and their fringes to observe fracture points/potential weaknesses in different materials and such. I have made a simple VI which allows me to draw a line on the ESPI image and output the light intensities to a waveform chart to make it easier to objectively determine the size of the plastic region (area where fracturing is most likely to occur).
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Solved!
Go to Solution.
Attachments:
line.vi ‏50 KB
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Hi itschad,
did you read the context help of the chart? There it is shown what datatype you need to wire to plot more than one curve on the some chart...
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test horizontal shift.vi ‏48 KB

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hi!!
Everything is in the title!! I've made an XY graph and I would like to convert it into a waveform. To create this XY graph I give only the coordinates of each point.
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Hi
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How can I label the peak in the waveform graph!

Hello, my question is a little vague. I try to narrate it clearly.
Thank you for your patience!
I work with Labview 7.1. At a word, My question is how to label the
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1.Open the Why.VI and execute it.
2.Click in the 'Acquire signal', then you will find two modes to upload
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mode need the support from the hardware, while 'Read' mode just upload file
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Attachments:
Calculate velocity.vi ‏271 KB
why.llb ‏389 KB
Acquire.vi ‏213 KB

Sorry, I try to compress the files in '.rar' ,but it is compatible with the web,I have to
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Attachments:
signal.txt ‏684 KB
Save file.vi ‏103 KB
Get Waveform Time Array(0).vi ‏46 KB

Calculating intersection of circles giving NaN first 'round'.

See attachment.
When I give the correct parameters as input, the output is always NaN.
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Solved!
Go to Solution.
Attachments:
Calculate Intersection Circles.vi ‏32 KB

marvin117 wrote:
What's the point of local variables if they don't work that way?
Although local variables are often demonized, there are proper uses for them. Coming from a text-programming background, you're used to using variables and, presumably, not accustomed to things happening in parallel. The first thing I noticed, which is certainly not obvious to anyone, is that your local variables are read in every frame of the Sequence structure immediately, but the indicators aren't written until the calculations happen in the first frame. In this way, the Sequence structure is highly non-intuitive. National Instruments owes you an apology for that.
The second thing I noticed was, in your second frame, that you were using the results of calculations with a local variable in the same frame. You'll never be able to know that the calculations will happen before the locals are read. There's your classic race condition.
I (almost) only use local variables to update front panel control values. If I find myself using them to read control values, I hang my head and wish I had designed my code better. Try to think in terms of "The wire is the variable." It's almost always the right way to think about data, and data flow.
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Coordinates of intersection of waveform

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