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Questions tagged [bspline]

A B-spline (basis spline) is the generalization of the Bézier curve which has minimal support with respect to a given degree, smoothness, and domain partition.

A B-spline (basis spline) is the generalization of the Bézier curve which has minimal support with respect to a given degree, smoothness, and domain partition.

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Difficulties to use scipy.interpolate BSpline: "TypeError: 'list' object cannot be interpreted as an integer"

From here: splrep enables to compute B-Spline knots, coefficients and degree from a path and a smooth factor splev enables interpolation using the resulting B-Spline BSpline enables to build a spline directly from knots, coefficients and…
lalebarde
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How to find a point on a b-spline that is on the normal plane of a point on another b-spline using goemdl / nurbs

So the first problem will be explaining what I am after clearly. I have two non-rational 3D b-splines. The first b-spline it the guiding spline. The second b-spline is a reference and it is essentially 'inside' of the first spline. ( the splines…
Burtski
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My output is off using b-spline function in R

I'm trying to find the coefficients of a function using b-spline in R. However there's something weird with the result. I used the R output coefficients to find y-hat then the square error and it is way off. I don't know what went wrong with my…
moistbananacake
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Nested bSpline basis on R

Im using the bSpline function on R (under the splines2 package) and I'm a little confused on the output. My understanding was that if I made sure the knot sequence was nested, then the columns produced in bSpline should also be nested. However, this…
Exc
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B-spline in standard polynomial representation

Is there a straightforward procedure for converting/representing a fitted B-spline to standard polynomial equations for each ‘between-knot’ piece/segment? It seems it should be possible but I can’t find a straightforward description of how spline…
rgm
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scipy.signal.bspline in python ,filter or interpolate?

I got this problem when I'm reading the code for face recognition，and what I'm sure about is this function is not a interpolation function, the interpolation function about Bspline is from package scipy.interpolate,which should be written as spline…
MATRIX1995
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Understanding Curve Global Approximation algorithm

Problem description I am trying to understand and implement the Curve Global Approximation, as proposed here: https://pages.mtu.edu/~shene/COURSES/cs3621/NOTES/INT-APP/CURVE-APP-global.html To implement the algorithm it is necessary to calculate…
Koenigsberg
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How to make a b-spline cubic curve with 4 points in C# Unity

I need to calculate a 4-point cubic non-uniform B-Spline (p0, p1, p2, p3) that interpolates p0 and p3. Until Now I was able to make the function calculate the curve but I don't know how to add the multiplicity at points p0 and p3 to do the…
rudieri bauer
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When using P-splines to fit data, does the dataset need to be divided into validation set and testing set?

I am doing the curve fitting by p-splines(with the basis b-splines) in a 1D dataset. I am struggling that in almost every regression model, it is essential to divide the dataset into a validation set and a testing set, to see if the data fits well…
Git
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scipy.interpolate problems with inputing values

Currently trying to use scipy's implementation of interpolate to create a uniform cubic B-spline (clamped). When using interpolate.splev() the target (x) value I pass in is changed and the function returns me the x value of a point near but not the…
Decadz
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Find the radius ( or curvature ) at a point on a bspline using geomdl / nurbs

I would like to find the curvature at a given point on a 3D b-spline. I believe that I want to use the derivatives of the spline at that point to calculate the curvature at that point but I do not understand how. I have defined a 3D bspline (taken…
Burtski
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What is the meaning of evaluating a spline's basis function?

I'm trying to understand the workflow for implementing the bspline basis function. tauf Vd 0 0 0.048 502.8944826 0.072 743.5034753 0.096 791.2514106 0.12 825.3244319 0.144 858.1731717 0.168 889.1381766 0.192 …
Ankit Bansal
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How can I give specific x values to `scipy.interpolate.splev`?

How can I interpolate a hysteresis loop at specific x points? Multiple related questions/answers are available on SOF regarding B-spline interpolation using scipy.interpolate.splprep (other questions here or here). However, I have hundreds of…
AJMA
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Insert new control points over an image

I'm trying to make an automatic non-rigid image registration using B-Splines as a deformation model, but I'm having some problems: Initially, I put a few control points (5x5), and after a long time, the result is good, but the processing time is…
Felippe Trigueiro
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How do I get the B-spline curve to connect to the final control point?

I am have a set of control points, and I am trying to draw a cubic B-spline (degree 3) based on these control points. The issue I'm experiencing is that my curve does not connect to the final control point, but instead it draws the curve to some…
jim bob
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