Displaying 20 results from an estimated 10000 matches similar to: "Plotting polynomial fit"
2003 Aug 16
2
Prediction Intervals (reposting)
(I'm reposting this message because the original has not appeared after
about 2 days. Sorry if it shows up twice.)
Hello.
First, thanks to those who responded to my recent inquiry about using
contour() over arbitrary (x,y) by mentioning the interp() function in
the akima package. That worked nicely. Now for a new question:
I would like to use a pair of prediction intervals to
2002 Nov 22
2
Need help with pipe()
Hello.
I have an R program that calls gawk (GNU Awk 3.06 for Windows) from
within pipe() to preprocess a large file before it is read into a data
frame with read.table().
I've recently upgraded from Win98SE to WinXP, and have also upgraded
from R1.5.0 to R1.6.1 over the past month or so. This program worked
before the upgrade(s), but now fails. I observe the following sort of
behavior with
2005 Mar 26
1
Trouble with expression() in R-win 2.0.1
Hi.
The following statement works fine in R-win 1.8.0, but yields a syntax
error in R-win 2.0.1 (and possibly in other versions after 1.8.0):
plot(c(1,2),main=expression(a==b==c))
I note that the following workaround executes successfully in both
versions of R...
plot(c(1,2),main=expression(a*"="*b*"="*c))
...but I don't really understand
2002 Jul 21
3
Date arithmetic fails (PR#1819)
Full_Name: Ronnen Levinson
Version: 1.5.1
OS: Mac OS 10.1
Submission from: (NULL) (12.232.201.92)
The value returned by strptime behaves badly after arithmetic operation and/or
combination.
> a=strptime("2002-06-01 12:15:01","%Y-%m-%d %H:%M:%S")
> a
[1] "2002-06-01 12:15:01"
> a+0
[1] "1932-04-25 21:46:45"
> a+3600
[1] "1932-04-25
2005 Mar 28
2
Generating list of vector coordinates
Hi.
Can anyone suggest a simple way to obtain in R a list of vector
coordinates of the following form? The code below is Mathematica.
In[5]:=
Flatten[Table[{i,j,k},{i,3},{j,4},{k,5}], 2]
Out[5]=
{{1,1,1},{1,1,2},{1,1,3},{1,1,4},{1,1,5},{1,2,1},{1,2,2},{1,2,3},{1
,2,4},{1,2,
5},{1,3,1},{1,3,2},{1,3,3},{1,3,4},{1,3,5},{1,4,1},{1,4,2},{1,4,3},
{1,4,
2002 Aug 23
1
Legends and Fonts
Hello.
Is it possible to set specify the font used by legend()? I would like to
specify a fixed-width font so that I can line up parts of vertically
stacked curve labels. For example, it would be nice if I could align the
names, ages, and weights in the following three curve labels:
Bob age=7 weight=100
Alexander age=13 weight=150
Susan age=20 weight=130
Is there perhaps a clever
2008 Mar 24
1
Cannot allocate large vectors (running out of memory?)
Hi.
As shown in the simplified example below, I'm having trouble allocating
memory for large vectors, even though it would appear that there is more
than enough memory available. That is, even with a memory limit of 1500 MB,
R 2.6.1 (Win) will allocate memory for a first vector of 285 MB, but not for
a second vector of the same size. Forcing garbage collection does not seem
2012 Feb 08
1
Fitting polynomial (power greater than 2)
Hey all, first time poster here. I'm new to R and working on my first real
programming and forecasting asignment. I'm using unemployment data from
1948-2012. I successfully completed part a and the linear fit for part b,
but i am really struggling fitting a polynomial with a power greater than 2
to my forecast. I'll upload my R code at the bottom. Any help is very much
appreciated!
2002 Aug 05
3
Formatting POSIXt values in plot axis labels
Hello.
I have an XYY series that I would like to graph with matplot() or some
other single function that will do the trick.
The X in question is a vector of POSIXt values obtained from strptime().
Is it possible to tell matplot() how to handle POSIXt x values?
I have examined the examples at
http://lark.cc.ukans.edu/~pauljohn/R/statsRus.html#5.22 , but would
prefer not have to overlay the
2003 Apr 29
1
polynomial fitting
I'm trying to find a way to fit a polynomial of degree n in x and y to
a set of x, y, and z data that I have and obtain the coefficients for
the terms of the fitted polynomial. However, when I try to use the
surf.ls function I'm getting odd results.
> x <- seq(0, 10, length=50)
> y <- x
> f <- function (x, y) {x^2 + y}
> library(spatial)
> test <-
2011 Jul 07
1
Polynomial fitting
Hello,
i'm fairly familiar with R and use it every now and then for math related
tasks.
I have a simple non polynomial function that i would like to approximate
with a polynomial. I already looked into poly, but was unable to understand
what to do with it. So my problem is this. I can generate virtually any
number of datapoints and would like to find the coeffs a1, a2, ... up to a
given
2007 Aug 15
1
Polynomial fitting
Hi everybody!
I'm looking some way to do in R a polynomial fit, say like polyfit
function of Octave/MATLAB.
For who don't know, c = polyfit(x,y,m) finds the coefficients of a
polynomial p(x) of degree m that fits the data, p(x[i]) to y[i], in a
least squares sense. The result c is a vector of length m+1 containing
the polynomial coefficients in descending powers:
p(x) = c[1]*x^n +
2009 Sep 28
2
Polynomial Fitting
Hello All,
This might seem elementary to everyone, but please bear with me. I've
just spent some time fitting poly functions to time series data in R
using lm() and predict(). I want to analyze the functions once I've
fit them to the various data I'm studying. However, after pulling the
first function into Octave (just by plotting the polynomial function
using fplot() over
2008 Jan 07
3
Polynomial fitting
I wonder how one in R can fit a 3rd degree polynomial to some data?
Say the data is:
y <- c(15.51, 12.44, 31.5, 21.5, 17.89, 27.09, 15.02, 13.43, 18.18, 11.32)
x <- seq(3.75, 6, 0.25)
And resulting degrees of polynomial are:
5.8007 -91.6339 472.1726 -774.2584
THanks in advance!
--
Jonas Malmros
Stockholm University
Stockholm, Sweden
2003 Aug 13
1
Contour plot for arbitrary (x,y,z)
Hello.
Is there an easy-to-use contour plot function analogous to scatterplot3d
that can draw handle a dataset of arbitrary (x,y,z) triplets? That is,
say x, y, and z are each measured quanties, and exhibit neither order
nor regularity.
I looked at the lattice package function "contourplot" but it seems
complicated, and it's not clear from the documentation whether it can
2007 Apr 16
2
Plotting data with a fitted curve
Suppose you have a vector of data in x and response values in y. How
do you plot together both the points (x,y) and the curve that results
from the fitted model, if the model is not y ~ x, but a higher order
polynomial, e.g. y~poly(x,2)? (In other words, abline doesn't work
for this case.)
Thanks,
--Paul
--
Paul Lynch
Aquilent, Inc.
National Library of Medicine (Contractor)
2005 Apr 27
1
Closing RGui help windows
Hi.
I often wind up with many help windows cluttering my RGui screen when
running Windows R 2.0.1. Is there an R instruction to close one or more
help windows, or an RGui command to close all help windows?
Yours truly,
/Ronnen.
/P.S. E-mailed CC:s of posted replies appreciated.
[[alternative HTML version deleted]]
2004 Dec 03
3
Computing the minimal polynomial or, at least, its degree
Hi,
I would like to know whether there exist algorithms to compute the
coefficients or, at least, the degree of the minimal polynomial of a square
matrix A (over the field of complex numbers)? I don't know whether this
would require symbolic computation. If not, has any of the algorithms been
implemented in R?
Thanks very much,
Ravi.
P.S. Just for the sake of completeness, a
2004 May 06
5
Orthogonal Polynomial Regression Parameter Estimation
Dear all,
Can any one tell me how can i perform Orthogonal
Polynomial Regression parameter estimation in R?
--------------------------------------------
Here is an "Orthogonal Polynomial" Regression problem
collected from Draper, Smith(1981), page 269. Note
that only value of alpha0 (intercept term) and signs
of each estimate match with the result obtained from
coef(orth.fit). What
2013 Apr 27
2
Polynomial Regression and NA coefficients in R
Hey all,
I'm performing polynomial regression. I'm simulating x values using runif() and y values using a deterministic function of x and rnorm().
When I perform polynomial regression like this:
fit_poly <- lm(y ~ poly(x,11,raw = TRUE))
I get some NA coefficients. I think this is due to the high correlation between say x and x^2 if x is distributed uniformly on the unit interval