interpolation

interpolate 3D volume with numpy and or scipy

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In scipy 0.14 or later, there is a new function scipy.interpolate.RegularGridInterpolator which closely resembles interp3. The MATLAB command Vi = interp3(x,y,z,V,xi,yi,zi) would translate to something like: from numpy import array from scipy.interpolate import RegularGridInterpolator as rgi my_interpolating_function = rgi((x,y,z), V) Vi = my_interpolating_function(array([xi,yi,zi]).T) Here is a full example demonstrating both; it will help you understand … Read more

Property binding vs attribute interpolation

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Property binding like [trueValue]=”…” evaluates the expression “…” and assigns the value “true” evaluates to the value true “Y” is unknown. There is no internal Y value in TypeScript and no property in the component class instance, which is the scope of template binding. In this case you would want [trueValue]=”‘Y'” Note the additional quotes … Read more

problematic Moire pattern in image produced with gnuplot pm3d and pdf output

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This is not supposed to be a solution, but rather an explanation and a possible, although ugly workaround. From time to time there are reports to the gnuplot mailinglists about this issue, but it seems to be related to the viewers. It has to do with the way gnuplot creates the surfaces plots. These are … Read more

How Do I Generate a 3-D Surface From Isolines?

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In MATLAB you can use either the function griddata or the TriScatteredInterp class (Note: as of R2013a scatteredInterpolant is the recommended alternative). Both of these allow you to fit a surface of regularly-spaced data to a set of nonuniformly-spaced points (although it appears griddata is no longer recommended in newer MATLAB versions). Here’s how you … Read more

Multivariate spline interpolation in python/scipy?

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If I’m understanding your question correctly, your input “observation” data is regularly gridded? If so, scipy.ndimage.map_coordinates does exactly what you want. It’s a bit hard to understand at first pass, but essentially, you just feed it a sequence of coordinates that you want to interpolate the values of the grid at in pixel/voxel/n-dimensional-index coordinates. As … Read more