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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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Find x from a given y in a spline function in R

What is the correct way of finding x from a given y from a spline function? library(cobs) library(tidyverse) # data dat <- tibble( x = c(seq(80, 360, 40),373.3), y = c(1.07, .85, .84, .97, 1.11, 2.02, 4.01, 7.99, 10.4) ) #…
FMM
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B-Spline transformation Vs Polynomial transformation in image registration

What is the difference between BSpline transformation based image registration and Polynomial transformation based image registration?
avinash kori
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How to control point movement directions for mouse-draggable points in matplotlib

Using the following as reference : Interactive BSpline Fitting I have the following tool to drag the points of the spline in any direction using mouse: import numpy as np from scipy.interpolate import interp1d from matplotlib.lines import…
snelzb
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How to find knot vector if control points are known for a NURBS curve?

I have a set of control points pts = [[849, 1181], [916, 1257], [993, 1305], [1082,1270], [1137,1181], [1118,1055], [993,1034], [873,1061], [849, 1181]] I have the logic for generating an…
snelzb
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Smooth interpolating spline has weird extremities

I'm building a soft to reject some trajectories that turn too fast. I managed to smooth them with scipy splrep and splev, but I have some weirdness at the beginning and the end, with some points that does not follow at all the original…
Tim
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Find the maxima points, of 3D surface B-Splice Python scipy bisplrep . Can sproot be used?

I want to find that x,y co-ordinates of all the local maxima of a 3D surface B-Spline made using bisplrep. splder, and sproot are used with splrep to find for single variate B-Spline. How is bisplrep maxima and minima found? My code is given…
Ayan Banerjee
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Using spline transformation in gbm function in R

I am trying to use spline transformation(bs function) in the boosting algorithm in R. (gbm function). However, when I write the following code it throws me an error: gbm(as.integer(cancel) ~ bs(log_tenure), data = train, distribution =…
DS_Enthusiast
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Monotone spline in R

I'm trying to use the spline2 package in R to build a monotone spline. I'm having trouble in evaluating the model for new values of the independent variable. In general, I'm having trouble grasping R treatment of "predict" and its relation to…
cladelpino
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Interpolation with B-splines of varying degrees in C++

I'm trying to interpolate through a set of motion data points, using piecewise motions as defined by Wagner, so each data point contains 8 numbers. Each of those numbers forms a motion parameter, so I need to generate Bspline functions for each…
C.A
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How to correctly format NURBS curves for wavefront .OBJ file format?

I am trying to write a wavefront .OBJ file that contains 3D NURBS curves (not surfaces). I found the following link that describes how to correctly format curves and surfaces within .OBJ files: http://www.martinreddy.net/gfx/3d/OBJ.spec There is no…
chloelle
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References for Boehm's algorithm of knot insertion?

I'm implementing a program for rational b-spline motion, and am looking for some references about sing Bohm's algorithm for knot addition. Essentially, this is used to split the overall curve into multiple segments to avoid having to multiply…
cl40
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Dynamical splines library for C++

i am having a lot of datapoints (e.g: 1000) which display the lanes of the road. I am also getting new Datapoints for the same location (more measurement for same point) and for the next Datapoints. So i am getting the flow of the Datapoints. I want…
Nikolai
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How to interpolate 3d points by b-spline curve in matlab

I´m looking for a way to interpolate 3d points with a b-spline curve using matlab. So more or less spapi with x,y,z. Is there something matlab built-in?
P Alcove
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What is concept of degree at B-spline curve?

Thanks to you attention to my question. My question is what is concept of degree at B-spline curve as you as seen from the title. In the book that I am studying, only 'Degree' is given as a factor that changes the shape of the curve. I searched on…
Kim BeomSik
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extract matrix from bs (b spline) function output in R

Let x = c(1, 2, 3) be a vector. I use bs function in the splines package of R to generate a matrix of B splines evaluated at x. require(splines) x <- c(1, 2, 3) bs.x <- bs(x, knots = c(1.5, 2.5)) The output bs.x is as follows, 1 …
semibruin
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