Displaying 8 results from an estimated 8 matches for "viscosity".
2002 Jun 08
3
contour plot for non-linear models
...9;t been able to reproduce the plot either in R ( version 1.5 )
and S. It makes the axes and it puts the labels, but it doesn't shows
the contour lines.
Could you help me resolving this problem?
This is the code that appears in the book and I've been testing.
> fm0 <- lm(Wt*Time ~ Viscosity + Time -1, data= stormer)
> b0 <- coef(fm0); names(b0) <- c("b1", "b2")
> storm.fm <- nls(Time ~ b1*Viscosity/(Wt-b2), data = stormer, start=b0,
trace = T)
> bc <- coef(storm.fm)
> se <- sqrt(diag(vcov(storm.fm)))
> dv <- deviance(storm.fm)
>...
2010 Jan 13
1
plotting moving range control chart
I have been having the same problem as poster Hodgess, below. It appears
that her question was never answered, so I would like to share a solution
with the community.
The problem is the (apparent?) inability to produce moving range process
behavior (a.k.a. "control") charts with individuals data in the package
"qcc" (v. 2.0). I have also struggled with the same limitation in
2010 Aug 20
0
plotting moving range control chart with qcc. . .
...i and i+1, it'll fool qcc's range chart into plotting the
moving ranges (MR) as the range (R), computing the center line as the
average MR instead of the average R, and computing the control limits
as D3*MR and D4*MR instead of D3*R and D4*R.
My solution for qcc, using Montgomery's viscosity data in
"viscosity.txt":
batch viscosity phase
1 34.05 setup
2 34.40 setup
3 33.59 setup
...
observations <- read.table("viscosity.txt", TRUE)
require(qcc)
attach(observations)
# identify "observation" and "batch" columns...
2004 Aug 06
1
: (Lattice): Overlaying more than one trend surface using contourplot() and wireframe()
..................
################################################################################
g<- c(80,80,90,90,85,85,85,85,85,92.07,77.93,85,85)
h<- c(170,180,170,180,175,175,175,175,175,175,175,182.07,167.93)
Yield <- c(76.5,77.0,78.0,79.5,79.9,80.3,80.0,79.7,79.8,78.4,75.6,78.5,77.0)
viscosity <- c(62,60,66,59,72,69,68,70,71,68,71,58,57)
molwt <-
c(2940,3470,3680,3890,3480,3200,3410,3290,3500,3360,3020,3630,3150)
###################################################################################
## Fit 2-order Polynomial trend for Yield
Yield.ls <- surf.ls(2, g, h, Yield)
trsur...
2004 Oct 16
7
sapply and loop
Dear all,
I am doing 200 times simulation. For each time, I generate a matrix and
define some function on this matrix to get a 6 dimension vector as my
results.
As the loop should be slow, I generate 200 matrice first, and save them into
a list named ma,
then I define zz<-sapply(ma, myfunction)
To my surprise, It almost costs me the same time to get my results if I
directly use a loop
2004 Oct 16
7
sapply and loop
Dear all,
I am doing 200 times simulation. For each time, I generate a matrix and
define some function on this matrix to get a 6 dimension vector as my
results.
As the loop should be slow, I generate 200 matrice first, and save them into
a list named ma,
then I define zz<-sapply(ma, myfunction)
To my surprise, It almost costs me the same time to get my results if I
directly use a loop
2004 Oct 19
0
Question on Rprof(); was: Re: sapply and loop
...>>>
>>>I believe you parroted that from `Writing R Extensions', but failed to
>>>give proper credit!
>>>
>>> > library(MASS); library(boot); library(nls)
>>> > data(stormer)
>>> > storm.fm <- nls(Time ~ b*Viscosity/(Wt - c), stormer,
>>> > start = c(b=29.401, c=2.2183))
>>> > st <- cbind(stormer, fit=fitted(storm.fm))
>>> > storm.bf <- function(rs, i) {
>>> > st$Time <- st$fit + rs[i]
>>> > t...
2009 Apr 13
4
Physical Units in Calculations
Back in 2005 I had been doing most of my work in Mathcad for over 10 years.
For a number of reasons I decided to switch over to R. After much effort and
help from you folks I am finally "thinking" in R rather than thinking in
Mathcad and trying to translating to R. Anyway, the only task I still use
Mathcad for is calculations that involve physical quantities and units. For
example, in