similar to: How to seperate date and time into different columns?

Displaying 20 results from an estimated 11000 matches similar to: "How to seperate date and time into different columns?"

2009 Sep 05
8
Color index in image function
Dear All, I was looking for the color index in?image function,?such as from topo.colors(n) and etc. but still never found it. For instance, from the help menu. ########################################### # Volcano data visualized as matrix. Need to transpose and flip # matrix horizontally. image(t(volcano)[ncol(volcano):1,]) # A prettier display of the volcano x <- 10*(1:nrow(volcano)) y
2009 Sep 23
4
Problem in graph plotting
Dear All, Let: dp: depth of the?river tp: temperature with respect to depth We can?have a simple scatter plot, between depth as y-axis and temperature as x-axis,?by using a?plot function as shown?below. #####################? dp <- c(1,4,3,2,5,7,9,8,9,2) tp <- 1:10 plot(tp,dp, type= 'l') ##################### ? Could someone advice me on?the way to?plot the same pair of
2009 Sep 22
3
How to combine matrices?
Dear All, Let a, b and c are?three matrices with same no. of column but different no. of row. a <- matrix(1, 1, 2) b <- matrix(2, 2, 2) c <- matrix(3, 3, 2) Could someone help me to combine these matrices together as a single matrix? Thank you Fir
2010 Apr 02
4
Derivative of a smooth function
Dear All, I've been?searching for?appropriate codes to compute the rate of change and the curvature?of ?nonparametric regression model whish was denoted by a smooth function?but?unfortunately?don't manage to?do?it. I presume that such characteristics from a smooth curve can be determined by the first and second derivative operators. The following are the example of fitting a
2010 Aug 13
2
Kalman filter
Dear All, Could anyone?give me a hand?to suggest few packages in R to running Kalman prediction and filtration ? Thanks Fir
2009 Oct 02
2
How to speed up R with version 2.9.2?
Dear All, I'm sorry if my question does not suit with this R group. I have recently installed?R software with version 2.9.2, but i found the program took almost 1 minute as soon as it was opened, before it can be used. However,?the previous version 2.9.1 only take few seconds?after the menu bar was clicked. This circumstance has caused me to wait for couple of minutes as several R windows
2009 Sep 24
3
Color of the plot which correspond to the group of the observations
Dear All, ? Let: dp: depth of the river tp: temperature with respect to depth These pair of observations are in 3 different groups i.e: Obs. 1,3,5,7?from the first group Obs. 2,4 and?10?from second group Obs 6,8 and 9?from third group. We can have a simple scatter plot, between depth as y-axis and temperature as x-axis, with each pairs are denoted by a red dot, by using a plot function shown
2009 Jul 14
1
Problem with GroupedData
Hi,   I have an original data frame with 8 columns of variables, which are stored in 'data1' frame.   data1 <- read.csv("E:\\PHD GLASGOW UNIVERSITY\\Data\\R\\Colin\\Cailness21.csv") attach(data1) names(data1)   [1] "Date"       "d"          "m"          "y"          "Time"      [6] "Depth"      "Temp"      
2009 Oct 08
1
Slope between two points
Dear All, Let? 499 piece-wise lines were buit up by 500 pair of observations, via R code below. x <- 1:500 y <- rnorm(500) plot(x, y, type = 'b') I was trying to compute all the slopes?for the ?lines which were connected between two adjacent points. For instance,?slopes?of lines between first and second points, second and third points, and so on, until?between??points 499 and 500,
2009 Oct 21
1
How to find the interception point of two linear fitted model in R?
Dear All, Let have 10 pair of observations, as shown below. ###################### x <- 1:10 y <- c(1,3,2,4,5,10,13,15,19,22) plot(x,y) ###################### Two fitted? models, with ranges of [1,5] and [5,10],?can be easily fitted separately by lm function as shown below: ####################### mod1 <- lm(y[1:5] ~ x[1:5]) mod2 <- lm(y[5:10] ~ x[5:10]) #######################
2009 Nov 03
1
tapply function
Hi, I tried to use tapply function to find the mean of the data?in each group as the following command, but the result are NA, as there are several missing values in each group. tapply(data,group,mean) Could someone please advice me the way to ?ignore the missing data in order for the fucntion to run successfully? Thanks Fir
2011 May 04
3
best subset regression in R
Dear All,   Could someone please give some advice the way to do linear modelling via best subset regression in R? I'd really appreciate for your kindness.   Thanks, Kagba [[alternative HTML version deleted]]
2011 Feb 22
2
How to find points of intersection
Dear All, I'm looking an appropriate way in R to compute/estimate? points of intersection between a line and a curve and will really appreciate for any suggestion or ideas? Thank you, Fir
2009 Oct 15
2
Estimation in a changepoint regression with R
Dear All, I'm trying to do the estimation in a changepoint regression problem via R, but never found any suitable function which might help me to do this. Could someone give me a hand?on this matter? Thank you.
2011 May 04
2
Box-Cox transformation in R
Hi,   Could any one please help how I can transform data based on Box-Cox Transformations in R.   Any helps will be much appreciated.   thanks, Kagba [[alternative HTML version deleted]]
2004 Dec 03
4
seq.Date requires by
Hi, What is the reason for seq.Date to require the 'by' argument and not to default it to 1 in the example below? > seq(from=as.Date("1996-01-01"), to=as.Date("1996-12-01")) Error in seq.Date(from = as.Date("1996-01-01"), to = as.Date("1996-12-01")) : exactly two of `to', `by' and `length.out' / `along.with' must be specified
2011 Feb 10
1
Optimal choice of the threshold u in Peak Over Threshold (POT) Approach
Dear All, Could?someone please suggest me the way to calculate the optimal threshold in POT method via?any available ?packages in R? Thanks, Fir
2012 May 21
2
Error : can't dup NilClass, in Heroku
Hi, The application is deployed on Heroku, is based on Ruby 3.2.1 and Rails 1.9.2. Sometimes a function of my props starts throwing this error " StringUtils:dateTimeFromString, str , *can''t dup NilClass*" and I don''t understand the cause. it''s my function: require ''time'' module StringUtils
2011 Feb 22
2
How to find points of intersection between harmonic function and a line
Hi, Sorry for the very short explanation about the problem of intersection. I have a wave function monitored from the heart beat in a particular interval of times.?Apart?fom that, there is?a line with positive slope (e.g: y = x+2) which lies across the wave and intersect on a number of points. My problem is i have no exact equation for?such a?complex harmonic wave produced by the heart
2009 May 30
1
Spatiotemporal correlation function
Hi, I'm trying to compute  the spatiotemporal correlation matrix by using Delta Kronecker products of spatial and temporal correlation matrix  in R, but didn't find any delta Kronecker's operator in R. The operators in matrix such as multiplication, addition, eigen values/vector and etc is easily to find and used. Could someone help me, please? Cheers. Firdaus