Displaying 20 results from an estimated 10000 matches similar to: "-log10 of 0"
2011 Nov 18
3
Permutations
Hi all,
why factorial(150) shows the error out of range in 'gammafn'?
I have to calculate the number of subset formed by 150 samples taking 10 at
a time. How is this possible?
best
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2002 Oct 14
4
log10(), floor() combo issue?
Hi all,
in my search for a nice binary2decimal method, I received this nice
code (thanx to Uwe Ligges):
bindec <- function(b)
sum(as.integer(unlist(strsplit(b, ""))) * 2^(floor(log10(b)):0))
It fails, however, with:
> bindec(1000)
[1] 4
Warning message:
longer object length
is not a multiple of shorter object length in:
as.integer(unlist(strsplit(b, "")))
2012 Jun 22
2
Boxplot with Log10 and base-exponent axis
Dear all,
I would like to (i) produce boxplot graphs with axis in logarithm in base 10
and (ii) showing the values on the axis in 10^exponent format rather than
10E+exponent.
To illustrate with an example, I have some widely spread data that I chart
plot using boxplot() [figure on the left]; the log="y" option of boxplot()
I obtained the natural logarithm conversion of the data and
2007 Nov 20
1
xy.coords and log10
Is there a way to teach xy.coords, when given log="xy", or just "x"
or "y" separately, to do a decimal log10 instead of the natural log?
Cheers,
Alexy
2008 Feb 27
1
Warnings generated by log2()/log10() are really large/takes a long time to display
x <- rnorm(1e6);
y <- log(x); # or logb(x) or log1p(x)
w <- warnings();
print(object.size(w));
## [1] 480
str(w);
$ NaNs produced: language log(x)
- attr(*, "dots")= list()
- attr(*, "class")= chr "warnings"
y <- log2(x); # or log10(x)
w <- warnings();
print(object.size(w));
## [1] 8000536
str(w);
## List of 1
## $ NaNs produced: language
2008 Mar 05
5
nls: different results if applied to normal or linearized data
Dear all,
I did a non-linear least square model fit
y ~ a * x^b
(a) > nls(y ~ a * x^b, start=list(a=1,b=1))
to obtain the coefficients a & b.
I did the same with the linearized formula, including a linear model
log(y) ~ log(a) + b * log(x)
(b) > nls(log10(y) ~ log10(a) + b*log10(x), start=list(a=1,b=1))
(c) > lm(log10(y) ~ log10(x))
I expected coefficient b to be identical
2007 Aug 07
1
lm( ) for log10-transformed data
Dear help-list,
I would like to perform a linear regression on the log10 of the two
vectors ov.mag.min and res.600nm. The slope and intercept of the
regression I use to plot a wider range of ov.mag.min in a double log plot.
For a linear regression on only tow points, wouldn't I expect the
results for two.points.min to match pretty exactly res.600nm? It does
not seem to be the case here.
2013 Mar 26
6
How do I show real values on a log10 histogram
Hi,
I have a histogram with values logged to the base 10
hist(log10(x),breaks=60)
How do I show the log values on the x-axis and a second x-axis showing the
real values?
Thanks
--
Shane
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2011 Apr 09
1
loop and sapply problem, help need
Dear R experts
Sorry for this question
M1 <- 1:10
lcd1 <- c(11, 22, 33, 44, 11, 22, 33, 33, 22, 11)
lcd2 <- c(22, 11, 44, 11, 33, 11, 22, 22, 11, 22)
lcd3 <- c(12, 12, 34, 14, 13, 12, 23, 23, 12, 12)
#generating variables through sampling
pvec <- c("PR1", "PR2", "PR3", "PR4", "PR5", "PR6", "PR7",
2003 Nov 25
2
Lambert's W function
Hello List
does anyone have an R function for the Lambert W function? I need
complex arguments.
[the Lamert W function W(z) satisfies
W(z)*exp(W(z)) = z
but I could'nt even figure out how to use uniroot() for complex z]
--
Robin Hankin
Uncertainty Analyst
Southampton Oceanography Centre
SO14 3ZH
tel +44(0)23-8059-7743
initialDOTsurname at soc.soton.ac.uk (edit in obvious way; spam
2003 Oct 13
1
zapsmall with all values small (PR#4554)
Hi
If all values are small, zapsmall does not zap.
For example ...
> zapsmall(1e-24)
[1] 1e-24
> zapsmall(1e-24, digits=3)
[1] 1e-24
Problem appears to be in calculation of digits ...
mx <- max(abs(x[!ina]))
digits = if (mx > 0)
max(0, digits - log10(mx))
else
digits
If all values are small, mx is very small, log10(mx) is
2013 Mar 13
1
expression exponent labeling
Hi all,
I want to label an axis with exponents, but can't get it done with expression.
Any hints would be very welcome!
# simulated data, somewhat similarly distributed to my real data:
set.seed(12); d <- rbeta(1e6, 0.2,2)*150 ; d <- d[d>1e-8]
hist( d? , breaks=100)
# now on a logarithmically scaled axis:
hist(log10(d), breaks=100, xaxt="n")
abline(v=
2023 Dec 18
1
[External] Re: zapsmall(x) for scalar x
Does mFUN() really need to be a function of x and the NA values of x? I
can't think of a case where it would be used on anything but the non-NA
values of x.
I think it would be easier to specify a different mFUN() (and document this
new argument) if the function has one argument and is applied to the non-NA
values of x.
zapsmall <- function(x,
digits = getOption("digits"),
2011 Jun 30
2
volcano plot.r
Hello.
My name is Akashah. i work at metabolic laboratory. From my study, i found that volcano plot can help a lot in my section.
i already studied about the volcano plot and get the coding to run in R software, unfortunately, there is may be something wrong with the coding. This is because no graph appear, but no error (blue color text) was shown on the R console. Below is the coding for
2023 Dec 19
1
[External] Re: zapsmall(x) for scalar x
>>>>> Steve Martin
>>>>> on Mon, 18 Dec 2023 07:56:46 -0500 writes:
> Does mFUN() really need to be a function of x and the NA values of x? I
> can't think of a case where it would be used on anything but the non-NA
> values of x.
> I think it would be easier to specify a different mFUN() (and document this
> new argument)
2011 Jun 20
2
(no subject)
HELLO, anybody... could you help me to check the below coding for volcano.
what is the mistake?
what the plot could not display?
# volcano_plot.r
#
# Author: Amsha Nahid, Jairus Bowne, Gerard Murray
# Purpose: Produces a volcano plot
#
# Input: Data matrix as specified in Data-matrix-format.pdf
# Output: Plots log2(fold change) vs log10(t-test P-value)
#
#
2009 Jul 30
3
Looping through R objects with $ operator and tags
Hi all,
Suppose I want to set the values in a column to the log of the values
of another column like so:
object$LogDist <- log10(object$Distance)
How do I loop through the objects if I have object1, object2, etc to
perform this function?
object1$LogDist <- log10(object1$Distance)
object2$LogDist <- log10(object2$Distance)
object3$LogDist <- log10(object3$Distance)
I was trying to
2007 Nov 14
2
Help with Bartlett's test on linear model
Hi all,
I would like to test the homoegeneity of variances between several
linear model for some analysis of covariance. It seems that the
Bartlett's test is a good test to use but I am having problem using with
linear model and I cannot find any examples on the internet. There are
some examples for comparisons of variances but not linear models.
If I take the hellung data set, which is
2012 Jan 25
1
solving nls
Hi,
I have some data I want to fit with a non-linear function using nls, but it
won't solve.
> regresjon<-nls(lcfu~lN0+log10(1-(1-10^(k*t))^m), data=cfu_data,
> start=(list(lN0 = 7.6, k = -0.08, m = 2)))
Error in nls(lcfu ~ lN0 + log10(1 - (1 - 10^(k * t))^m), data = cfu_data, :
step factor 0.000488281 reduced below 'minFactor' of 0.000976562
Tried to increase minFactor
2006 Mar 23
2
Default lag.max in ACF
Hi,
The default value for lag.max in ACF implementation is 10*log10(N)
There several publications recommending setting lag.max to:
- N/4 (Box and Jenkins, 1970; Chatfield, 1975; Anderson, 1976;
Pankratz, 1983; Davis, 1986; etc.)
- sqrt(N)+10 (Cryer, 1986)
- 20<=N<=40 (Brockwell and Davis)
Why R uses 10*log10(N) as a default?
Please, give me a reference to a book or article where the