Displaying 20 results from an estimated 600 matches similar to: "hermite and Bezier splines"
2008 Oct 10
1
how to evaluate a cubic Bezier curve (B-spline?) given the four control points
I'm trying to use R to determine the quality of a cubic Bezier curve
approximation of an elliptical arc. I know the four control points
and I want to compute (x,y) coordinates of many points on the curve.
I can't find anything in either the base distribution or CRAN that
does this; all the spline-related packages seem to be about *fitting*
piecewise Bezier curves to a data set.
2011 Nov 22
1
Bezier curve in R?
Hi dear all,
I am wondering if there is a function existing in R that did the quadratic
bezier curve interpolation? I hope to generate a bezier curve based on
three sets of points: two end of the line and a control point.
Thanks in advance.
Tengfei
--
Tengfei Yin
MCDB PhD student
1620 Howe Hall, 2274,
Iowa State University
Ames, IA,50011-2274
[[alternative HTML version deleted]]
2007 Apr 26
1
[PATCH]Make wobbly's bezier patch to work with grids that aren't 4x4.
Hi,
Recently, I started taking a look at wobbly's source (I was interested
in it's physics... ;-))
I noticed that GRID_WIDTH and GRID_HEIGHT were defined to be 4, and I
wanted to see how the physics look like with grid sizes that aren't
4x4.
I changed the defines to my new grid size, but unfortunately it didn't work.
I investigated this "bug" (it's not exactly a bug
2004 Aug 19
3
Do you know if you can map a large minimum spanning tree in R?
Thanks Mike.
My data has longitude and latitude coords and I used distAB {clim.pact}
then mst {ape} to calculate my minimum spanning tree. The nodes are
telecoms sites from all over Australia. My goal is to determine the
minimum cost of linking them via cabling, and I'm starting by
calculating the distance "as the crow flies", but will probably
eventually need to calculate the
2004 May 28
3
gauss.hermite?
The search at www.r-project.org mentioned a function
"gauss.hermite{rmutil}". However, 'install.packages("rmutil")'
produced, 'No package "rmutil" on CRAN.' How can I find the current
status of "gauss.hermite" and "rmutil"?
Thanks,
Spencer Graves
2007 May 08
1
Piecewise cubic Hermite interpolation
Which function implements the piecewise cubic Hermite interpolation?
I am looking for equivalent of matlab's interp1 with the method = 'pchip'
Here is the reference
http://www.mathworks.com/access/helpdesk/help/techdoc/index.html?/access/helpdesk/help/techdoc/ref/interp1.html&
--
View this message in context:
2006 Feb 27
1
gauss.hermite function
Hi,
I am trying to find a function that returns simply the weights and
points of an n point gauss hermite integeration, so that I can use them
to fit a non-standard likelihood.
I have found some documentation for the function 'gauss.hermite' written
by jim lindley, but can't find the actual binary on CRAN
I'm aware there are lots of functions like glmm, glmmML etc to fit mixed
2012 May 09
2
problem with Gauss Hermite ( x and w )
Hi all,
I am using the 'gaussHermite' function from the 'pracma' library
############ CODES ###########
library(pracma)
cc=gaussHermite(10)
cc$x^2
cc$x^5
cc$x^4
############ CODES ###########
as far so good. However, it does NOT work for any NON integer values, say
############ CODES ###########
cc$x^(2.5)
cc$x^(-2.5)
############ CODES ###########
But just think about it
2004 Jun 21
2
sunrise, sunset calculation
Are there any functions available to calculate sunrise and sunset times
for given latitude,longitude and dates?
If not, I'll appreciatte any pointers to C code I could use/port.
Thanks,
Angel
2003 Jul 10
1
Contour Plots
Hello,
I'm a grad. student in statistics and am looking for some information on how
R draws its contours. I suspect you are using a Bezier spline. I have the
C code but am curious about how it works.
Riley A. Metzger
University of Waterloo
Waterloo, Ontario, N2L 3G1
(519) 888-4567 Ext. 3715
rileymetzger at alumni.uwaterloo.ca
2004 Aug 18
1
Do you know if you can map a large minmum spanning tree in R?
Do you know if you can map in R?
I have my minimum spanning tree, but as there are 1371 nodes (all over Australia) I'd like to be able to "graph" them as they actually would be on the map.
Do you know if this is possible?
2011 May 03
1
Compiling Rgraphiz on Windows 7 64bit with R-2.13.0
Hi all,
I am trying to compile Rgraphiz on Windows 7 64bit with R-2.13.0. I have
installed
Rtools213.exe from [1]. The 64bit packages in [2] provided me with the 64 bit
version
of graphviz. After intalling the binary version Rgraphviz 1.30 (in 32bit) it
complains (as
expected) that:
> library(Rgraphviz)
Error: package 'Rgraphviz' is not installed for 'arch=x64'
I
2011 Jul 28
3
smooth scatterplot and geo map
Hello everybody,
I'm trying to understand how to draw a smoothed scatterplot on a geographic
map with R.
Have a dataframe with point locations (long, lat) and was able to simply
plot these points on a shp map by using the maptools package. However,
instead of having simply the raw points on the map, I would like to have a
"smoothed" scatterplot of the same superimposed on the map.
2011 Feb 15
1
gList and gTree methods of grid::grobX
Dear all,
In an attempt to draw fill patterns in grid graphics, I have
encountered a behavior of grobX that I cannot understand from the
documentation. Consider this,
library(grid)
## gTree
g1 <- gTree(children=gList(
rectGrob(0.5,0.5, width=unit(0.8,"npc"),
height=unit(2,"cm")),
circleGrob(r=0.3)), vp=viewport(0.5,0.5))
##
2010 Aug 20
1
Surface generated as product of two curves
I have the following data table:
[,1] [,2] [,3] [,4] [,5]
[1,] 2575 1927 1754 581 354
[2,] 1156 810 730 541 237
[3,] 417 297 199 125 110
[4,] 281 132 132 47 58
[5,] 152 84 87 54 19
Each column represents a time interval expressed in nano-seconds
Each row represents an energy interval expressed m=n MeV
Each table value represents the average gamma rays intensity
2009 Apr 24
1
Managing DLLs with the same names in an R session
I am having a problem using two DLLs with the same name, but obviously
located in different directories, in an R session. The troublesome
package is the (Bioconductor) Rgraphviz package. It relies on (3rd party
software) graphviz and imports functions from (Bioconductor) package
graph. Unfortunately, the current stable release of graphviz for Windows
2011 Feb 12
1
R limits documented?
Is there documentation on R limits?
That is, max matrix size, etc.?
Diagnostics when limits are exceeded are not always
meaningful. For example:
> x <- rep(0,50000*50000)
Error in rep(0, 50000 * 50000) : invalid 'times' argument
In addition: Warning message:
In as.vector(data) : NAs introduced by coercion
Here's another example:
> library(orthopolynom)
> hermite <-
2011 Jul 29
5
HIRHAM netcdf files
Can someone help me out with a "small" problem?
I've started using netcdf files recently, and I want to extract the grid id
and also the coordinates from a HIRHAM netcdf file.
I know how to extract a slice of dataset both in space and in time and I
also know the area that this file should cover, however I have no idea
regarding the reference for both LAT/LON and RLAT/RLON.
I tried
2009 May 08
1
ADAPTIVE QUADRATURE WEIGHTS AND NODES
Can anyone help me on how to get the nodes and weights of the adaptive quadrature
using R.
Best wishes
Boikanyo.
-----
The University of Glasgow, charity number SC004401
2013 Feb 13
1
[lattice] display a projected map on a layerplot
summary: I can display a lon-lat map on a lattice::layerplot, and I
can display a Lambert conformal conic (LCC) map on a spam::image, but
I can't display an LCC map on a lattice::layerplot. Example follows.
What am I doing wrong?
details:
I've been using `lattice` (via `rasterVis`) successfully to display
global atmospheric data, which works well enough (though I am
definitely intrigued