Pi = griddata((x, y), p, (xi, yi), method='cubic') Vi = griddata((x, y), v, (xi, yi), method='cubic') Ui = griddata((x, y), u, (xi, yi), method='cubic') Yi = np.linspace(np.min(y),np.max(y),n_pts) X = data y = data u = data v = data p = data Value for every combination of xi and yi is returned in ui, vi and pi.
Note that xi and yi are arrays not necessarily of equal length and a The data interpolated on a uniform grid: xi, yi, ui, vi, pi. Plot - bool: show results, mainly used for debugging N_pts - int: number of points in the uniform grid.
ĭef interpolate_data_to_uniform_grid(data, n_pts=100, plot=False):Īpproximates unstructured data with a uniform gridĭata - a 2D numpy array with 5 columns: x, y, u, v, pThe function thankfully does that for us. plot the flow field, regularly spaced data is needed. To use the in-build python functions to e.g. Return np.array(x), np.array(y), np.array(u), np.array(v), np.array(p) #the tecplot file contains zone information and information on the #ignore lines with text and those that have a different number of entries Lines_list = file_handle.readlines() #read all linesįor line in lines_list: #go through each lineĮnt = line.split() # split into separate entries '''Read output file with 5 values: x, y, u, v, p ''' The following function will read those values from a file:įrom _future_ import absolute_import, division, print_function The output format is optimized for Tecplot and in this example, contains 5 values: x-position, y-position, x-velocity, y-velocity and pressure. I am using results calculated with oomph-lib, see this earlier tutorial. In the meantime, some quick code to get streamline trajectories in Python.
Paraview streamline length how to#
However, with neither do I know how to extract streamline trajectories.
Paraview streamline length software#
Tecplot is commercial software and I never had any problems plotting streamlines with it. Paraview is open-source and generally good, although on dense meshes, streamlines tend to stop randomly. Lots of visualization software offer the possibility to plot streamlines.
I recently found myself in the situation where I wanted to get the trajectories of streamlines starting from a specific point. Then use that as your Seed Source.Īnother (probably better) option if your data is 2D or you can extract an interesting surface along the flow of your data is to use the Surface LIC plugin. One thing you might want to try is to compute the vorticity of your vector field ( Gradient Of Unstructured Data Set when turning on advanced option Compute Vorticity), find the magnitude of that ( Calculator), and then use the Threshold filter to pull out the cells with large vorticity. Thus, you are better off with trying to derive a data set that contains seed points that are likely to trace a stream through the vortices that you are interested in. You will get all those interesting streamlines through vortices, but they will be completely hidden by all the boring streamlines around them.
Even worse, the result will be so dense that you won't be able to see anything. First of all, unless your data is trivially small, this will take a long time to compute and create a large amount of data. However, while you can do this, you will probably not be happy with the results. That will create a streamline originating from every point in your dataset, which is pretty much what you asked for.
To add a little bit to Mathieu's answer, if you really want streamlines everywhere, then you can create a Stream Tracer With Custom Source (as Mathieu suggested) and set your data to both the Input and the Seed Source.
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