Displaying 20 results from an estimated 7000 matches similar to: "Interpolation Problems"
2010 Aug 25
3
approxfun-problems (yleft and yright ignored)
Dear all,
I have run into a problem when running some code implemented in the
Bioconductor panp-package (applied to my own expression data), whereby gene
expression values of known true negative probesets (x) are interpolated onto
present/absent p-values (y) between 0 and 1 using the *approxfun -
function*{stats}; when I have used R version 2.8, everything had
worked fine,
however, after updating
2009 Mar 25
1
Interpolate x from y
Is it possible to interpolate a value for x with knowledge of y?
For example, approx(x, y, xout) will give me y's given a set of x's,
which is opposite to what I'm after. I've tried switching x and y,
e.g., approx(y, x, xout), but in a real data set it is possible to
have more than one y for a given x causing approx() to remove
coordinates.
Thanks for your help,
Greg.
2013 Feb 14
1
approxfun values
Readers,
According to the help '?approxfun', the function can be used to obtain
the interpolated values. The following test was tried:
> testinterpolation<-read.csv('test.csv',header=FALSE)
> testinterpolation
V1 V2
1 10 2
2 20 NA
3 30 5
4 40 7
5 50 NA
6 60 NA
7 70 2
8 80 6
9 90 9
10 100 NA
>
2009 Jan 08
2
interpolation to abscissa
Readers,
I have looked at various documents hosted on the web site; I couldn't
find anything on interpolation. So I started r and accessed the help
(help.start()). (by the way is it possible to configure r to open help
in opera instead of firefox?) Initially I read the help for the akima
package but couldn't understand it. Next I tried the asplines package
help.
I tried to copy the
2006 Jul 17
3
information about a function
Hi people,
I am new in this list and could not find a FAQ for it in particular,
furthermore I could not find my question answered in the official R
FAQ or docs.
I have simply something like this:
> f<-approxfun(data[,1],data[,2])
and f is:
> f
function (v)
.C("R_approx", as.double(x), as.double(y), as.integer(n), xout = as.double(v),
as.integer(length(v)),
2010 Sep 15
1
approxfun returning value higher than I would expect
Below is the code that I am using in a much larger function. I would
expect a bankfull measure at zero to be between 0.6 and 0.8 approxfun
is returning 0.8136986. I am sure that I am missing something.
measure_bkf <- (structure(list(measurment_num = c(0, 0.2, 0.4, 0.6,
0.8, 1, 1.2,
1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4), bankfull_depths_m
= c(-0.48,
-0.48, -0.42, -0.26, 0.58,
2007 Sep 04
3
how to do interpolation
Hello R Users,
How to make a variable equidistance with time i.e. how to interpolate a
variable if it is not sampled at equal time interval.
Many thanks,
Regards,
Yogesh
[[alternative HTML version deleted]]
2008 May 29
1
akima interpolation and triangulation question
Dear all;
First of all, this is probably a more conceptual question than a
R-related one, but still want to give it a try. When working with the
interpolation function "interp" from the package akima and the
triangulation function "tri.mesh" from package tripack I've got NA's
for the interpolation and "error" for the triangulation. The data is
arranged in a
2011 May 04
1
bivariate linear interpolation
Hi,
I have three matrices (X,Y,P) with the same dimension. The X,Y grid is
regular and I want to
perform linear interpolation to pick out certain points. In matlab
appropriate call is
something like
Pout=interp2(X,Y,P,Xout,Yout, method="linear")
where Xout and Yout are the locations where I want the Pout data
(typically a different grid).
(Scipy has this routine in
2004 Aug 16
3
bus error /segmentation fault from 'approx' (PR#7177)
Full_Name: joerg van den hoff
Version: 1.9.1
OS: MacOS and SunOS
Submission from: (NULL) (149.220.4.88)
follow up to ID 7166. something like
approx(c(1,2),c(NA,NA),1.5,rule=2)
crashes 1.9.1 on both systems (MacOS 10.3.5.: bus error, SunOS 5.9:
segmentation fault) even if xout is within given x range (as in example above)
where rule=2 seems not be relevant anyway.
2009 Jun 21
1
Problems with bilinear interpolation of a grid
Dear all,
I'm having trouble interpolating a number of gridded datasets that I have. I'm quite new to R so any help/advice that can be offered would be much appreciated!
Firstly I'll describe my dataset. The data is a grid of the planet at 1 degree spatial resolution, with each grid cell containing a value describing a particular variable (e.g. population density) for coordinate
2013 Jan 17
1
Help with interpolation
hi guys
I need to interpolate values for the zero coupon yield curve. Following data
is given
date days rate
1996 01
2007 Mar 15
1
How to use result of approxfun in a package?
I am working on a project where we start with start with 2 long,
equal-length vectors, massage them in various ways, and end up with a
function mapping one interval to another. I'll call that function
"f1." The last step in R is to generate f1 as the value of the
approxfun function. I would like to put f1 into a package, but
without having the package redo the creation of
2013 Jan 16
1
function approx interpolation of time series data sets
Readers,
Am trying to use the function 'approx' to interpolate time series data sets:
data1:
01:23:40 5
01:23:45 10
01:23:50 12
01:23:55 7
data2:
01:23:42
01:23:47
01:23:51
01:23:54
The objective is to obtain interpolated values of 'data1' column 2 (5,
10, 12, 7) for the times shown in data2. Tried the following command
but received the error shown:
2011 Nov 16
3
Interpolating hourly basis
I have a huge data set in the form of
V1 V2 V3 V4 V5 V6
1 201005010000201005010000 1.68291.38 1 0
2 201005010000201005010300 0.93335.10 1 0
3 201005010000201005010600 2.25 57.38 1 0
4 201005010000201005010900 0.43 13.76 1 0
5 201005010000201005011200 0.74101.14 1 0
I am interested in interpolating it on an hour basis(it's for avery
2008 Jun 19
1
error related to approxfun in R 2.7.0
I'm testing R version 2.7.0 on windows and there seems to be a
compatibility issue with objects that were created by "approxfun" in
older versions. As long as the objects were created in version 2.7.0
things work ok, but calling the interpolated functions from R version
2.0.1 causes this error:
Error in .C("R_approx", as.double(x), as.double(y), as.integer(n),
xout =
2019 May 08
3
[R] approx with NAs --> new argument 'na.rm=TRUE' ?!
>>>>> Robert Almgren
>>>>> on Fri, 3 May 2019 15:45:44 -0400 writes
[ __ to R-help __ -- here diverted to R-devel on purpose]
> There is something I do not think is right in the approx()
> function in base R, with method="constant" and in the
> presence of NA values. I have 3.6.0, but the behavior
> seems to be the same in
2003 Sep 21
3
Z aware interpolation
Hello again,
There is any package which does Z aware (real 3D) interpolations?
It can be any method (IDW, kriging or spline) but it should take into
consideration not only x and y coordinates for interpolation, but
also z coordinate. I looked into different packages but it seems i
didn't find the right one.
The ultimate goal is to import the output into a GIS (Geographical
Information
2004 Jun 21
1
Novice question: Smooth interpolation of survival curve
Greetings,
How might one go about generating a smooth interpolation of a survival
curve generated by the survfit function in the survival package? I am
able to package my variables by standard methods
>x<-(survfit(Surv(time),data)
and plot the "step" curve, but would like to obtain a smooth estimation
curve for the purpose of approximating survival time between steps on
the
2013 Apr 25
1
Linear Interpolation : Missing rates
Dear R forum
I have data.frame as
df = data.frame(rate_name = c("USD_1w", "USD_1w", "USD_1w", "USD_1w", "USD_1m", "USD_1m", "USD_1m", "USD_1m", "USD_2m", "USD_2m", "USD_2m", "USD_2m", "GBP_1w", "GBP_1w", "GBP_1w", "GBP_1w",