I tried to express two displacement values in one waveform chart.
I have two displacement sensors, one is a digital input sensor and the other is analog input sensor.
I have to see those values in one waveform chart simultaneously.
In my attempts, two VIs of each instruments were combined into one VI. I found the error that when I ran the VI, only one VI would report values and not both simultaneously.
By any chance, is there a way to run it at the same time and see the values on one graph?
Let me share a few scenarios that might help solve your issue.
Plot multiple doubles on a chart: bundle them together and put the resulting cluster into a chart.
bundled doubles on a chart
Two VIs measuring a double and plotting those results.
bundled subvi outputs to a chart
You could similarly plot boolean values (your digital input sensor) by using the boolean to 0,1 VI first (converts the T/F to 1/0 respectively) and that can be bundled as above.
(These are the most direct/easiest ways of doing this; you have a number generator and you bundle the numbers to a graph).
Of course, I can imagine that your question might actually be about how to share values from parallel-running subVIs. If that's the case, say so and this answer can be edited to point you in the right direction.
Related
I download the following graph-cut code:
https://github.com/shaibagon/GCMex
I compiled the mex files, and ran it for pre-defined image in the code (which is rgb image)
I wanna optimize the image segmentation results,
I have probability map of the image, which its dimension is (width,height, 5). Five probability distribution over the image dimension are stacked together. each relates to one the classes.
My problem is which parts of code should according to the probability image.
I want to define Data and Smoothing terms based on my application.
My question is:
1) Has someone refined the code according to the defining different energy function (I wanna change Unary and pair-wise formulation).
2) I have a stack of 3D images. I wanna define 6-neighborhood system, 4 neighbors in current slice and the other two from two adjacent slices. In which function and part of code can I do the refinements?
Thanks
I am new to VTK and am trying to compute the Dice Similarity Coefficient (DSC), starting from 2 meshes.
DSC can be computed as 2 Vab / (Va + Vb), where Vab is the overlapping volume among mesh A and mesh B.
To read a mesh (i.e. an organ contour exported in .vtk format using 3D Slicer, https://www.slicer.org) I use the following snippet:
string inputFilename1 = "organ1.vtk";
// Get all data from the file
vtkSmartPointer<vtkGenericDataObjectReader> reader1 = vtkSmartPointer<vtkGenericDataObjectReader>::New();
reader1->SetFileName(inputFilename1.c_str());
reader1->Update();
vtkSmartPointer<vtkPolyData> struct1 = reader1->GetPolyDataOutput();
I can compute the volume of the two meshes using vtkMassProperties (although I observed some differences between the ones computed with VTK and the ones computed with 3D Slicer).
To then intersect 2 meshses, I am trying to use vtkIntersectionPolyDataFilter. The output of this filter, however, is a set of lines that marks the intersection of the input vtkPolyData objects, and NOT a closed surface. I therefore need to somehow generate a mesh from these lines and compute its volume.
Do you know which can be a good, accurate way to generete such a mesh and how to do it?
Alternatively, I tried to use ITK as well. I found a package that is supposed to handle this problem (http://www.insight-journal.org/browse/publication/762, dated 2010) but I am not able to compile it against the latest version of ITK. It says that ITK must be compiled with the (now deprecated) ITK_USE_REVIEW flag ON. Needless to say, I compiled it with the new Module_ITKReview set to ON and also with backward compatibility but had no luck.
Finally, if you have any other alternative (scriptable) software/library to solve this problem, please let me know. I need to perform these computation automatically.
You could try vtkBooleanOperationPolyDataFilter
http://www.vtk.org/doc/nightly/html/classvtkBooleanOperationPolyDataFilter.html
filter->SetOperationToIntersection();
if your data is smooth and well-behaved, this filter works pretty good. However, sharp structures, e.g. the ones originating from binary image marching cubes algorithm can make a problem for it. That said, vtkPolyDataToImageStencil doesn't necessarily perform any better on this regard.
I had once impression that the boolean operation on polygons is not really ideal for "organs" of size 100k polygons and more. Depends.
If you want to compute a Dice Similarity Coefficient, I suggest you first generate volumes (rasterize) from the meshes by use of vtkPolyDataToImageStencil.
Then it's easy to compute the DSC.
Good luck :)
I am trying to minimize a specific spectral coefficient in respect to a set of parameters involved in my array, using the global optimization VI, and the process gets stuck. Maybe I am using the wrong VI I don't know. Here are screenshots of my code:
and the sub-VI that's referenced:
Basically it averages an array (which values are a linear function of three parameters) over one dimension then gets a certain coefficient of its power spectrum, after that the main VI tries to minimize that coefficient in respect to the three aforementioned parameters. Any ideas?
Given 2 open Polyhedron3 made of triangles in CGAL, I want to cut the first one with the second one. That is, all intersecting triangle facets from poly2 should cut facets from poly1 and create new edges (and faces) in poly1 following the path of intersection. In the end, I need the list of edges/half edges which are part of the intersection path.
I'm using a typedef CGAL::Simple_cartesian Kernel.
While this looks like a boolean operation, it's not because there's no 'inside' or 'outside' for open meshes. The way I tried to implement it is:
build an AABB for mesh 1 (to be cut)
find intersecting faces from mesh1 cut by the first triangle of mesh 2
compute intersection infos using cgal : this returns the intersection description, but with some problems:
cgal will sometimes return 'wrong' intersections (for exemple, segments of 0 length)
the first mesh is not cut in the operation. Given the intersection description, I have to cut triangles myself (unless there's a function I've overlooked in cgal to cut a face/triangle given an intersection). This is not a trivial problem, as there are lots of corner cases
repeat with next face of poly2
My algorithm sorts of works, but I sometimes have problems : path not closed, small numerical accuracy problem, and it's not very fast.
So here's (at last) my question : what would be the recommended way to implement such an operation in a robust way ? Which kernel would you recommend?
Following sloriot comment, I've spent some time playing with the code of the CGAL polyhedron demo. Indeed it contains a plugin corefinement which does what I want. I've not finished integrating all changes in my own code base but I believe I can mark this question as answered.
All thanks to SLoriot for his suggestion!
Pascal
I am working on a program that needs to fit numerous cosine waves in order to determine one of the parameters for the function. The equation that I am using is y = y_0 + Acos((4*pi*L)/x + pi) where L is the value that I am trying to obtain from the best fit line.
I know that it is possible to do this correctly by hand for each set of data, but what is the best way to automate this process? I am currently reading in the data from text files, and running a loop with the initial paramiters changing until I have an array of paramater values that have an amplitude similar to the data, then I check the percent difference between points on the center peak and two end peaks to try to pick the best one. It in consistently picking lower values than what I get when fitting by hand (almost exactly one phase off). So is there a way to improve this method, or another method that works better?
Edit: My LabVIEW version has a cos fitting VI which is what I am using, the problem is when I try to automate the fitting by changing the initial parameters using a loop, I cant figure out how to get the program to pick the same best fit line as a human would pick.
Why not just use a Fast Fourier Transform? This should be way faster than fitting a cosine. In the result vector of complex numbers look for the largest peak of in the totals. You're given frequency (position in the FFT result vector), amplitude and phase.
You can evaluate the goodness of the fit by computing the difference between fitting curve and your data. A VI does this in the "Advanced curve fitting" palette. Then all you have to do is pick up the best fit.