Re: [R] deriv; loop
francogrex wrote:
Hi, 2 questions:
Question 1: example of what I currently do:
for(i in 1:6){sink(temp.txt,append=TRUE)
dput(i+0)
sink()}
x=scan(file=temp.txt)
print(prod(x))
file.remove(C:/R-2.5.0/temp.txt)
But how to convert the output of the loop to a vector that I can manipulate
(by prod or sum etc), without having to write and append to a file?
So, do you want the file at the end or not? If not:
x - 1:6
prod(x)
and if this is really the solution you want, the please read the posting
guide and the manuals before posting again.
Question 2:
deriv(~gamma(x),x)
expression({
.expr1 - gamma(x)
.value - .expr1
.grad - array(0, c(length(.value), 1), list(NULL, c(x)))
.grad[, x] - .expr1 * psigamma(x)
attr(.value, gradient) - .grad
.value
})
BUT
deriv3(~gamma(x),x)
Error in deriv3.formula(~gamma(x), x) : Function 'psigamma' is not in the
derivatives table
What I want is the expression for the second derivative (which I believe is
trigamma(x), or psigamma(x,1)), how can I obtain that?
By using some algebraic software (rather than a numeric one) or
contributing complete derivatives tables for the next R release.
Uwe Ligges
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
[R] deriv; loop
Hi, 2 questions:
Question 1: example of what I currently do:
for(i in 1:6){sink(temp.txt,append=TRUE)
dput(i+0)
sink()}
x=scan(file=temp.txt)
print(prod(x))
file.remove(C:/R-2.5.0/temp.txt)
But how to convert the output of the loop to a vector that I can manipulate
(by prod or sum etc), without having to write and append to a file?
Question 2:
deriv(~gamma(x),x)
expression({
.expr1 - gamma(x)
.value - .expr1
.grad - array(0, c(length(.value), 1), list(NULL, c(x)))
.grad[, x] - .expr1 * psigamma(x)
attr(.value, gradient) - .grad
.value
})
BUT
deriv3(~gamma(x),x)
Error in deriv3.formula(~gamma(x), x) : Function 'psigamma' is not in the
derivatives table
What I want is the expression for the second derivative (which I believe is
trigamma(x), or psigamma(x,1)), how can I obtain that?
Thanks
--
View this message in context:
http://www.nabble.com/deriv--loop-tf4166283.html#a11853456
Sent from the R help mailing list archive at Nabble.com.
__
R-help@stat.math.ethz.ch mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] deriv; loop
for question 1, is this what you want (BTW allocate 'result' to the
size you want - the example keeps extending it which is OK for small
numbers, but for larger size preallocate):
result - numeric(0)
for (i in 1:6) result[i] - i
result
[1] 1 2 3 4 5 6
prod(result)
[1] 720
On 7/29/07, francogrex [EMAIL PROTECTED] wrote:
Hi, 2 questions:
Question 1: example of what I currently do:
for(i in 1:6){sink(temp.txt,append=TRUE)
dput(i+0)
sink()}
x=scan(file=temp.txt)
print(prod(x))
file.remove(C:/R-2.5.0/temp.txt)
But how to convert the output of the loop to a vector that I can manipulate
(by prod or sum etc), without having to write and append to a file?
Question 2:
deriv(~gamma(x),x)
expression({
.expr1 - gamma(x)
.value - .expr1
.grad - array(0, c(length(.value), 1), list(NULL, c(x)))
.grad[, x] - .expr1 * psigamma(x)
attr(.value, gradient) - .grad
.value
})
BUT
deriv3(~gamma(x),x)
Error in deriv3.formula(~gamma(x), x) : Function 'psigamma' is not in the
derivatives table
What I want is the expression for the second derivative (which I believe is
trigamma(x), or psigamma(x,1)), how can I obtain that?
Thanks
--
View this message in context:
http://www.nabble.com/deriv--loop-tf4166283.html#a11853456
Sent from the R help mailing list archive at Nabble.com.
__
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem you are trying to solve?
__
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
