similar to: slightly off-topic re prcomp()

Displaying 20 results from an estimated 9000 matches similar to: "slightly off-topic re prcomp()"

2004 Sep 07
6
Further png() question
Ok, I have reinstalled R-1.9.0 and this appears to have fixed the problems I was having with png(). However, I have a further question regarding png() Is it possible to pass a par() argument to the png() command? I am wanting to produce 4 plots per object, which I normally acheive on an X window by par(mfrow=c(1,4)). I have tried calling a new plot and setting par in this way but this has no
2005 Feb 16
4
Passing colnames to graphics title
Hi, Just a quick query - if I'm creating a function to produce a number of histograms per page of output (one per column from a matrix), how can I pass the column name of the matrix into the title (or indeed to form part of the x-axis label)? TIA, Laura Laura Quinn Institute of Atmospheric Science School of Earth and Environment University of Leeds Leeds LS2 9JT tel: +44 113 343 1596 fax:
2004 Nov 14
2
Exporting to file: passing source name to file name in loop
Hi, I'm having a mental block as to how I can automatically assign filenames to the output of the following code. I am wishing to create a separate .png file for every image created, each of them having a sequential filename ie "sourcefile_index.png" so that I can create a movie from them. Please could someone tell me where I am going wrong? the following code works fine and
2006 Jan 28
3
Creating 3D Gaussian Plot
Hello, I requested help a couple of weeks ago creating a dipole field in R but receieved no responses. Eventually I opted to create a 3d sinusoidal plot and concatenate this with its inverse as a means for a "next best" situation. It seems that this isn't sufficient for my needs and I'm really after creating a continuous 3d gaussian mesh with a "positive" and
2005 Mar 01
3
Reconstructing Datasets
Hi, Is it possible to recreate "smoothed" data sets in R, by performing a PCA and then reconstructing a data set from say the first 2/3 EOFs? I've had a look in the help pages and don't seem to find anything relevant. Thanks in advance, Laura Laura Quinn Institute of Atmospheric Science School of Earth and Environment University of Leeds Leeds LS2 9JT tel: +44 113 343 1596
2005 May 16
3
Mental Block with PCA of multivariate time series!
Please could someone point me in the right direction as I appear to be having a total mental block with fairly basic PCA problem! I have a large dataframe where rows represent independent observations and columns are variables. I am wanting to perform PCA sequentially on blocks of nrows at a time and produce a graphical output of the loadings for the first 2 EOFs for each variable. I'm sure
2006 Feb 20
1
Further rgl()/spheres3d() query
Hi, I am applying the following code to map pca loadings onto a 3d grid, my problem is this - the output only plots the spheres in the requested color (in this case "red") for the first argument. The sphere from the second argument appear as flat dark circles. Also the text3d() command only seems to work for a couple of the positions, with no text added in most cases. Could anyone offer
2004 Aug 15
3
Stacking Vectors/Dataframes
Hello, Is there a simple way of stacking/merging two dataframes in R? I want to stack them piece-wise, not simply add one whole dataframe to the bottom of the other. I want to create as follows: x.frame: aX1 bX1 cX1 ... zX1 aX2 bX2 cX2 ... zX2 ... ... ... ... ... aX99 bX99 cX99 ... zX99 y.frame: aY1 bY1 cY1 ... zY1 aY2 bY2 cY2 ... zY2 ... ... ... ... ... aY99 bY99 cY99 ...
2005 Feb 02
2
Runnning R remotely
Hi, I was wondering if anyone might be able to help. I am trying to run R on a remote machine, part of the model run I am attempting writes an external file output as a png (about 48 iterations per model run). I am running R 1.9.1 on SuSe9.0, and am accessing this via ssh from a Debian machine. Initially I used the command ssh -X IP.address and whilst I was able to run the model successfully the
2006 Jan 22
3
White Noise
I'm wanting to create a series of near-identical matrices via the addition of "white noise" to my starting matrix. Is there a function within R which will allow me to do this? Thank you Laura Quinn Institute of Atmospheric Science School of Earth and Environment University of Leeds Leeds LS2 9JT tel: +44 113 343 1596 fax: +44 113 343 6716 mail: laura at env.leeds.ac.uk
2004 Oct 19
2
Slope of surface
Hi, Is there a neat way of working out the slope of a flat surface in R? Given (x,y,z) co-ordinates of the four corners of a square, is there a function which will allow me to calculate the "mean" slope of the surface in a given direction? Thanks in advance.. Laura Laura Quinn Institute of Atmospheric Science School of Earth and Environment University of Leeds Leeds LS2 9JT tel: +44
2005 May 16
2
Fitting Contour to Data Points
Apologies for the mass mailing today! I am attempting to produce a contour plot for phsical data on a map matrix. I have a small number of data points which each has an (x,y) co-ordinate together with a corresponding value which I would like to cvreate a contour plot for. I have tried the following code: contour(data$x,data$y,data$value) but am told: Error in contour.default(data$x, data$y,
2004 Sep 12
2
boxplot() from list
I have a list containing 48 objects (each with 30 rows and 4 columns, all numeric), and wish to produce 4 boxplot series (with 48 plots in each) , one for each column of each object. Basically I want a boxplot from boxplot(mylist[[]][,i]) for i in 1:4. It seems that I can create a boxplot of length 48 from the entire list, but I don't seem able to subscript to return 4 boxplots from the list
2004 Sep 06
1
Applying function to lots of separate data sets
I have a total mental block and can't find my way around this seemingly simple problem: I have created a function such that: my_answer_1=myfuntion(my_input_1) I am wanting to perform this calculation over a large number of datasets, but am having real difficulty calling and assigning - i think the problem les in the fact that I need to paste for call and assign. this is my best attempt so
2007 Feb 08
1
Point estimate from loess contour plot
Hi, I was wondering if anyone knows of a way by which one can estimate values from a contour plot created by using the loess function? I am hoping to use the loess contour plot as a means of interpolation to identify the loess created values at points at pre-defined (x,y) locations. Could anyone point me in the right direction please? Thanks. Laura Quinn Institute of Atmospheric Science School
2004 Oct 06
4
Performing Analysis on Subset of External data
Hi, I want to perform some analysis on subsets of huge data files. There are 20 of the files and I want to select the same subsets of each one (each subset is a chunk of 1500 or so consecutive rows from several million). To save time and processing power is there a method to tell R to *only* read in these rows, rather than reading in the entire dataset then selecting subsets and deleting the
2006 Feb 13
1
Saving surface3d Output
Hello, Please could someone advise if it's possible to save the graphical output from the surface3d() function? I have tried the dev.copy() function to save as a pdf but an error message says I cannot copy from the null device. Laura Quinn Institute of Atmospheric Science School of Earth and Environment University of Leeds Leeds LS2 9JT tel: +44 113 343 1596 fax: +44 113 343 6716 mail:
2006 Jan 27
2
How do I "normalise" a power spectral density analysis?
Hi everyone Can anyone tell me how I normalise a power spectral density (PSD) plot of a periodical time-series. At present I get the graphical output of spectrum VS frequency. What I want to acheive is period VS spectrum? Are these the same things but the x-axis scale needs transformed ? Any help would be greatly appreciated Tom
2005 Feb 03
0
Interpretation of PC loadings
Hello, Following on from a paper by Ludwig, Horel and Whiteman in 2004, I have been using PCA to identify surface wind patterns. In the paper they approach the problem using the "real vector approach", that is, they create paired (u,v) vectors for the wind data, in effect artificially doubling the number of variables, then perform the pca, subsequently repairing the output and plotting
2013 Feb 04
6
Script for conditional sums of vectors
Hi guys, I hope you can help me with this (probably) simple query: I have a data frame: -------------------------- a=c(1,1,1,1,1,1,2,2,2,2,2,2) b=c(1,1,1,2,3,4,1,1,2,2,3,4) c=c(400,200,300,100,500,300,200,100,500,400,200,100) data=data.frame(a=a,b=b,c=c) -------------------------- And I would like to get the following output: -------------------------- b a 1 2 3 4 1 900 100 500 300 2