Displaying 20 results from an estimated 400 matches similar to: "the plotting position of theoretical quantile for qqnorm"
2006 Apr 13
2
Plotting positions in qqnorm?
Do you know of a reference that discusses alternative choices for
plotting positions for a normal probability plot? The documentation for
qqnorm says it calls ppoints, which returns qnorm((1:m-a)/(m+1-2*a))
with "a" = ifelse(n<=10, 3/8, 1/2)? The help pages for qqnorm and
ppoints just refer to Becker, Chambers and Wilks (1988) The New S
Language (Wadsworth & Brooks/Cole),
1999 Mar 16
1
qqnorm in R-0.63.3
Dear List,
invoking qqnorm-plots in Version 63.3 produces funny things:
using the option `type="s"ยด on qqnorm should give a nice *line* of
observed quantiles. Now, the line is walking along in order to the
points index instead from lowest to highest, wich makes funny slopes.
try x <- table(rnorm(1000) # or similar and
qqnorm(x,type="s") # in 0.63.2 and 63.3
Well, the
1998 Sep 03
2
ppoints
When I look at ppoints I see:
ppoints<-function (x)
{
n <- length(x)
if (n == 1)
n <- x
(1:n - 0.5)/n
}
However Venables & Ripley (2nd ed, p 165) say ppoints() should return
(i-1/2)/n for n>=11; (i-3/8)/(n+1/4) for n<=10.
The version below should work as described:
ppoints<-function (x)
{
n <- length(x)
if (n <= 10)
(1:n - 0.375)/(n + 0.25)
else
(1:n - 0.5)/n
2012 Jan 11
12
[PATCH 00/11] Btrfs: some patches for 3.3
The biggest one is a fix for fstrim, and there''s a fix for on-disk
free space cache. Others are small fixes and cleanups.
The last three have been sent weeks ago.
The patchset is also available in this repo:
git://repo.or.cz/linux-btrfs-devel.git for-chris
Note there''s a small confict with Al Viro''s vfs changes.
Li Zefan (11):
Btrfs: add pinned extents to
2005 Jan 19
1
ppoints (PR#7538)
Dear r-bugs,
Whilst playing with ppoints I discovered
that when one uses it directly, occasional
NA's in a vector also become data fractions:
ppoints(c(1,2,NA,4))
Would it be a good idea to add a warning message
as in:
ppoints <- function (n, a = ifelse(n <= 10, 3/8, 1/2))
{
if(any(is.na(n))) warning("'n' contains NA's")
if(length(n) > 1) n <-
2000 Dec 11
1
qqline (PR#764)
I think qqline does not do exactly what it is advertised to do ("`qqline'
adds a line to a normal quantile-quantile plot which passes through the
first and third quartiles."). Consider the graph:
tmp <- qnorm(ppoints(10))
qqnorm(tmp)
qqline(tmp)
The line (which I expected go through all the points), has a slightly
shallower slope than does the points plotted by qqnorm. I think
2011 Oct 08
5
defrag makes fragmentation worse
Kernel 3.1-rc8
btrfs-progs-0.19
mount options: noatime,autodefrag (space_cache is enabled)
There are snapshots present on the filesystem.
When I do a btrfs fi defrag on a file, the file becomes much more
fragmented. The end result can be a file with 20k times more fragments
than before. Initially I thought the extents were just smaller but
were next to each other, so I checked with both
2007 Jun 19
2
Function -return value
Hi, I am trying to write a function with the following codes and I would like
it to return the values for "alpha
beta para parab " seperately. Then I would like to use this funstion for
"variable" with factor "a" and "b". But the result turns out to be a matrix
with element like "Numeric,2" ... I guess they are just the values for
2012 Sep 17
13
[PATCH 1/2 v3] Btrfs: use flag EXTENT_DEFRAG for snapshot-aware defrag
We''re going to use this flag EXTENT_DEFRAG to indicate which range
belongs to defragment so that we can implement snapshow-aware defrag:
We set the EXTENT_DEFRAG flag when dirtying the extents that need
defragmented, so later on writeback thread can differentiate between
normal writeback and writeback started by defragmentation.
This patch is used for the latter one.
Originally patch
2012 May 11
1
identify() doesn't return "true" numbers
Dear R community.
I am using the identify() function to identify outliers in my dataset.
This is the code I am using:
####################################################################
# Function to allow identifying points in the QQ plot (by mouseclicking)
qqInteractive <- function(..., IDENTIFY = TRUE)
{
qqplot(...) -> X
abline(a=0,b=1)
if(IDENTIFY) return(identify(X))
1999 Aug 31
1
Suggestion for qqplot() improvement
>>>>> On Tue, 31 Aug 1999 14:57, Werner Stahel <stahel@stat.math.ethz.ch> said:
WSt> Here is a suggestion. It seems that qqplots, comparing a sample
WSt> to a distribution other than the normal, are not explicitly
WSt> available in S or R. I found
(in S-plus / Trellis it is, see below)
WSt> qqplot(y, rt(300, df = 5))
WSt> as an
2012 Jan 30
3
[PATCH] Btrfs: allow cloning ranges within the same file
It''s safe and easy to do so, provided the ranges don''t overlap.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
fs/btrfs/ioctl.c | 23 ++++++++++++++++-------
1 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 0b06a5c..8fcd671 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2223,8 +2223,6 @@ static
2006 Mar 02
2
Bug/Wishlist: 'partial' in 'sort' and 'quantile' (PR#8650)
Hi,
This is essentially a reposting of
http://tolstoy.newcastle.edu.au/R/devel/05/11/3305.html
which had no responses, and the behaviour reported there persists in
r-devel as of yesterday.
(1) sort() with non-null partial
> x = rnorm(100000)
> keep = as.integer(ppoints(10000) * 100000)
> system.time(sort(x))
[1] 0.05 0.00 0.04 0.00 0.00
> system.time(sort(x, partial = keep))
[1]
2001 Jul 02
2
Shapiro-Wilk test
Hi,
does the shapiro wilk test in R-1.3.0 work correctly? Maybe it does, but can
anybody tell me why the following sample doesn't give "W = 1" and
"p-value = 1":
R> x<-1:9/10;x
[1] 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
R> shapiro.test(qnorm(x))
Shapiro-Wilk normality test
data: qnorm(x)
W = 0.9925, p-value = 0.9986
I can't imagine a sample being
2003 Aug 06
1
probability plot correlation coefficient
As a newbie to R, I'm still rather at a loss for finding information
(the commands names can be rather arcane)so I'm just posting my question:
I would like to estimate the shape coefficient of diverse
distributions (Weibull, gamma and Tukey-Lambda specifically, but other
could be of interest)
- Does R have a PPCC utility to estimate such parameter?(maximum value
of correlation coef)
2011 Jun 08
1
[PATCH] Btrfs: use join_transaction in btrfs_evict_inode()
The WARN_ON() in start_transaction() was triggered while balancing.
The cause is btrfs_relocate_chunk() started a transaction and
then called iput() on the inode that stores free space cache,
and iput() called btrfs_start_transaction() again.
Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
fs/btrfs/inode.c | 2 +-
1 files
2011 Sep 08
1
[PATCH] Btrfs: fix direct-io vs nodatacow
To reproduce the bug:
# mount -o nodatacow /dev/sda7 /mnt/
# dd if=/dev/zero of=/mnt/tmp bs=4K count=1
1+0 records in
1+0 records out
4096 bytes (4.1 kB) copied, 0.000136115 s, 30.1 MB/s
# dd if=/dev/zero of=/mnt/tmp bs=4K count=1 conv=notrunc oflag=direct
dd: writing `/mnt/tmp'': Input/output error
1+0 records in
0+0 records out
btrfs_ordered_update_i_size() may return
2010 Nov 16
2
[Btrfs-Progs] Update for lzo support
- Add incompat flag, otherwise btrfs-progs will report error
when operating on btrfs filesystems mounted with lzo option.
- Allow to turn on lzo compression for defrag operation:
# btrfs filesystem defragment -c[zlib, lzo] <file>
Note: "-c zlib" will fail, because that''s how getopt() works
for optional arguments.
Signed-off-by: Li Zefan
2004 Apr 06
2
percentile-percentile plot
Hi,
Is there a function that does percentile-percentile plot. I do not mean
the qqplot. I need to plot the percentiles rather than points themselves.
I am hoping for a plot that tells me that the x percentile of one data set
corresponds to the y percentile of the other. for example a point on the
plot of (.5, .2) will tell me that the 50th percentile of the first data
and the 20th percentile of
2003 Jul 18
2
Probability plotting with R
Hello,
Our professor asked us to do probability plotting using weibull paper,
exponential paper, normal, log-normal paper, etc. I know I can create Q-Q
plot for normal dist. and see if all te points are on one line. How do I
go about other distributions?
I tried generating different samples and use the general qq function.
However, I could not do it since I don't know the population