Interpolation of curve with loops

[altenbach]

Of course once you upgrade to LabVIEW 8.0, things get quite a bit easier 😉

1. The interpolation routines are much richer and the spline inperpolation can be done with a single tool.
2. We have events for "cursor move", making it easy to implement the program with event structures.

In 8.0 you could do something like in the attached picture. As you can see, we no longer need to read 10 property nodes per iteration, just the single changed cursor location, and the loop only spins if a cursor is moved. 😄

Message Edited by altenbach on 04-11-2006 08:18 AM

[ny]

I'm making a laser show system as a school projet.

I need to have ordered different méthode curves to from an image.

so far I can have  ordered multi plot curves, but when I insert them together to a table of XY coordonates the curves don't seem to be set in order. Or there's some wrong coordonates that slip in the table. I've been working on this for hours. can someone look it trough?

[Tyler]

Ny,

  Could you explain what you want the VI to do. I am having a hard time following what you are exactly saying. Make sure to explain things such as "set in order" and "slip in table." Let us know what you want the functionality to do and we can see if there are any suggestions we can give you.

Tyler H.

National Instruments

[ny]

Hi

Sorry I was short on words on my previous post. I fixed the problem I had but I need help with something else.

What I need is software that make image frames for my laser show system. Those frames are made of XY coordinates that I send to 2 controllers that drive 2 mirrors. One mirror is for the X axis and the other is for the Y axis. What I have is serie of point that are made with the XYspline methode I found on this tread. I load a bmp image and place the cursors on the contours of the image. But the results I get aren't very accurate so I guess I need something else. Is there a way to lock the cursor on the black pixels so I could place the cursors more accuratly? I will be making annimations with those frames so they need to be pretty exact.

I also tried using Vision with the edge detector tools but what I get is contour points that aren't in any order to fit a curve in them. What I need a serie continuous XY data that will drive my laser and form an image.

There is also some stuff I read about on vector image file. I would need to extract those vectors make a serie of points and display them in a XY graph. But I have no idea on how I would do that, we didn't learn anyting on manipulating vectors in my Labview classes. and my teacher says it would take me weeks to do that. Time is what I don't have. I just finished building the system so that leaves my almost no time to make it run.

Any suggestions on how I coud make those frames would help.

This is what I have so far. LaserShowprojectedimage.vi  displays what my laser system displays. XYspline labview fonctionne.vi is the VI I use so far to make the frames. butterfly.txt is the points I traced and butterfly.bmp is the results I want to get.

[kupikupi]

hi .... i went thru the example posted earlier and tried to create a program based on that..

as i noticed .. the input of X and Y is determined by the moving the cursor. and are input into the interpolation vi. in an array form .. but when i tried using my own data which is also in an array form ,. it doesnt work. can i get some help here?

i'm doing motion recognition

what i am trying to do is get the centroid of the object in every image frames and try to plot them on a graph. then i want to match the shape of the graph (which represents the path of the motion) with a database. but since spline interpolation only allow increasing value of the x-axis. i have to separate them into 2 graphs and combine them later on which is done in the example vi.

when i created my own program .. i only get the points but i dont get the spline interpolated graph.

i'm attaching my vi here. i hope somebody can help me .. thanks ..

[altenbach]

Sorry, I don't have any of the IMAQ functions installed. Could you...

1. create indicators at all the output tunnels of the loop that generates the data.
2. run the VI once to populate these indicators.
3. delete the loops that generate the data
4. right-click on each indicator created in step (1) and select "change to constant".
5. Save the VI under a new name and attach it again.

Now we have a VI with built-in default data for testing. 🙂

[kupikupi]

hi altenbach,


thanks for the reply

i am actually trying to normalize the data 1st so that it can match the database.

the number of centroids in each motion will not always be the same between the aquired data and the data so i have to normalize both datas so that i can compare every point in each set of data... please help me check whether i am doing the right thing ..

i have attached new modified vi ... can u please help me to check why i can't get a nice plot like wat u got ... thanks...

andreas

Message Edited by kupikupi on 09-06-2006 09:54 AM

[altenbach]

Normalizaion will not help, you need to truncate each path to the nonzero values. You also don't need the cursors.

try this!

[kupikupi]

hi altenbach ..

i havent tested it with my database yet but i think that's what i want... i'll come back if i've got problems...

thanks very much

[kupikupi]

hi altenbach..

i've got a problem with the array part of the program .....

say i've got 5 sets of data with diferent size ...  3 5 3 4 3  .. so at the truncated array part ... i insert  3 5 3 4 3 ...

but the above is only for that set of data.... i will always have sets of data with different size..

my problem is . how do i actually get rid of the 0 in the array ... the zeros only comes out because i enabled indexing and the output array takes the size of the biggest array ...

how do i eliminate the zeros??

thanks..