similar to: Problem on minima

Displaying 20 results from an estimated 900 matches similar to: "Problem on minima"

2002 Feb 25
4
replace NAs
Dear R community: it is possible to replace NA?s in a data frame with zeroes? what should I do? Thanks in advance Juan Pablo _________________________________________________________________ MSN Photos es la manera m?s sencilla de compartir e imprimir sus fotos: http://photos.latam.msn.com/Support/WorldWide.aspx -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
2002 Mar 29
2
order()
Hi, In the order() help file, there is an example like: a <- c(4, 3, 2, NA, 1) b <- c(4, NA, 2, 7, 1) z <- cbind(a, b) (o <- order(a, b)); z[o, ] How can I do something like "order a in ascending order, b in descending order"? And say I have a third vector c, and I'd like to add this to the previous condition "a ascending, b descending, c
2002 Mar 18
4
Plot 3d
There exists a plot 3d functions (or similar) in R? Thanks, ======================================== Cezar Freitas (ICQ 109128967) IMECC - UNICAMP Campinas, SP - Brasil -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe"
2002 Mar 19
5
matrix with fix number columns but variable number rows
I have to store a number of vectors of the same length. I know the length but I do not know the number of vectors. How can I store them as they are created (they are created one by one)? -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or
2002 Mar 20
3
tex/latex output?
Is it possible to write the output/results (redirect) to a latex file? Jeff. Jeff D. Hamann Hamann, Donald & Associates, Inc. PO Box 1421 Corvallis, Oregon USA 97339-1421 Bus. 541-753-7333 Cell. 541-740-5988 jeff_hamann at hamanndonald.com www.hamanndonald.com -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read
2002 Aug 20
4
plot and bg
Hi all, I would like to plot some points and define the bg color of my graphics. But the bg parameter set is defined for the. whole graphic. In fact, i would like to use something like : box(bg=gray(0.9)). So, the background concerns only the plot region and not the main title, the x title and the y title. The option col for the function box() concerns the contour and there is no option
2002 Feb 11
4
Multiple graph pages
Dear R users: I am a relatively experienced Splus user but new to R, using the version for Windows 2000. Splus allows the user to generate multiple graph pages in the graph window. For example, if you have two plot(...) commands in the script than two pages in the graph window will be created. However, when I tried this in R, the second plot will just overwrite the first plot in the graph
2003 Jan 06
1
On nlm
Dear all, I have to minimize a (real) function in a loop (say i in (1:1000)) and store its ``$estimate'', via l2estim<-nlm(f.minimo,c(-.01,0.1))$estimate into a vector for further analisys. Since the function's behaviour is quite peculiar (in the sense that in the simulation study it may not have a minumum), sometimes I get the the warning Error in nlm(minimo, c(-0.01, 0.1),
2006 May 04
0
R: R: [Re:] function to replace missing values with median value?]]
oops!, I pressed the 'send' key too soon, ... see ?replace replace(x, is.na(x), median(x, na.rm=T)) take also a look at the function itself > replace function (x, list, values) { x[list] <- values x } <environment: namespace:base> Stefano >-----Messaggio originale----- >Da: r-help-bounces at stat.math.ethz.ch >[mailto:r-help-bounces at
2000 Jan 19
1
R for the Mac
Hello, usually work with S-plus and/or with R, which I do prefer, on a Window paltform. Now I downloaded R for the Mac (I run it on a G4 at home) but I found that many, too many functions are not available (svd, lm, glm and so on... but still the lapply is missing...!). I have ProFortran a C++ routine of my own but I can't pass them to that version of R. Is there anybody going to give a little
2010 Dec 20
2
How to optimize function parameters?
Hi, I have a dataset and I want to fit a function to it. The function is variogram model (http://en.wikipedia.org/wiki/Variogram) The variogram model is defined by three parameters and I want them to be automatically optimized for real time data. I tried to use gafit {gafit} for this, but there are some data configuration, where optimal results given by gafit() are negative, which is not correct
2010 May 22
1
How to find all single minima, i.e. only each one within each next part of analyzed vector (table)
Dear R users, How to find all single minima within each next part of analyzed vector (table) Select all minima (mass_value=min & mass_value<2) (many) in vector(table), BUT first put mask on table in order to select within one window mask (5 elements) only one local minimum, and next to search within the next time window mask the second minimum (only one local along second mask)
2013 Mar 20
0
unexpected local minima/maxima with surf.gls
Hi there, I use the surf.gls() function to fit a variable measured over a surface. When I plot the predicted surface, there are local minima/maxima in almost every coordinate where data were measured, which seems aberrant. For instance: ?? x <- c(343,293,343,243,293,343,443,543,593,243,293,343,393,443,493,543,593,143,193,243,293,343,393,443,
2005 Jun 15
1
Finding local minima and maxima
I have data in the form of (x,y) pairs and would like to find local minima and maxima (typically the zeros of the 2nd derivative) of the y values. I looked at numericDeriv, but I don't have an "expression" per se. I looked at optim, also, but it looks like it will find only one "global" max or min. I can code up my own piecewise derivatives, but wondered if there is
2009 Nov 03
2
1 dimensional optimization with local minima
I am using numerical optimization to fit a 1 parameter model, in which the input parameter is bounded. I am currently using optimize(), however, the problem turns out to have local minima, and optimize does not always seem to find the global minimum. I could to write a wrapping function that tries multiple intervals or starting values, but I would prefer a package that has built-in methods to make
2002 Mar 27
2
Error with nls
Dear R-group members, I use: platform i386-pc-mingw32 arch x86 os Win32 system x86, Win32 status major 1 minor 4.1 year 2002 month 01 day 30 language R I try to fit a 2 compartment model. The compartments are open, connected to each other and
2011 May 25
0
approximate function and find local peaks (Maxima or Minima)
Hi, I have a data-matrix: > CB                    Zeit                Low 2   2011-05-02 08:05:05 7596.0 3   2011-05-02 08:10:06 7593.5 4   2011-05-02 08:15:11 7594.5 5   2011-05-02 08:20:15 7597.5 6   2011-05-02 08:25:18 7595.0 7   2011-05-02 08:30:20 7593.5 8   2011-05-02 08:35:21 7593.0 9   2011-05-02 08:40:21 7593.0 10  2011-05-02 08:45:25 7599.0 11  2011-05-02 08:50:34 7596.0 12 
2005 Nov 11
1
optim not giving correct minima
Hello, I am trying to use optim() on a function involving a summation. My function basically is a thinned poisson likelihood. I have two parameters and in most cases optim() does a fine job of getting the minima. I am simulating my data based on pre specified parameters, so I know what I should be getting. However when my true parameters fall in a particular range, optim() gives
2001 Mar 10
2
Is availble CA, GA or MAS available for R for Win?
Hi. Does anyone know whether CA(Cellular Automata), GA(Genetic Algorithm) or Multi-Agent System is available for R for Win? I've already knowna software for these areas, SWARM or startlogo. But I'd like to link R's function with these methods. -------------- next part -------------- An HTML attachment was scrubbed... URL:
2005 Sep 23
2
Strange behaviour of as.Date function
Dear All, I'm happily extracting data of temperature from an oracle db under R via RODBC. After manipulating the extracted data I put them into a data.frame 'dati' which is as follows: > dati DATA tm. UDINE/RIVOLTO tm.TORINO/CASELLE 1 2005-07-01 22.35 23.80 2 2005-07-02 22.70 22.85 3 2005-07-03 23.80