similar to: PCA analysis

Displaying 20 results from an estimated 2000 matches similar to: "PCA analysis"

2010 Apr 27
1
Symbols in biplot
Hello all, I just started in on R today. I am at the point where I am trying to distinguish different groups of data (hydrochemical data) in biplot. I search and found a post about converting the sample number in biplot to a symbol like x or + "> temp <- matrix(runif(50), nrow=10) > temp.pca <- princomp(temp) > biplot(temp.pca, xlabs=c("A", "A",
2008 Aug 07
2
colouring a tree
Hi all. I would be very pleased if someone could help me, as I do not seem to get the different branches of my tree painted in different colours. The closest I get is colouring the names of my samples(=names of the branches). Here is the code. data <- read.table(file = "S://SEDIM//TRFLP//B12.5_50-700bp.txt" , as.is = TRUE, header = TRUE, sep = "\t", row.names =
2010 Oct 20
1
Biplot: plot group name instead of row number
Dear list, I'm trying to make a biplot, but instead of plotting the row number for each observation, plot a group factor. Example: prcomp(iris[,1:4]) -> PCA biplot(PCA) #this makes a nice biplot but with row names Instead of row numbers I want to plot iris[,5], which is a factor. I can do this: plot(PCA$x[,1], PCA$x[,2], type="n") text(PCA$x[,1], PCA$x[,2], labels=iris[,5],
2009 Feb 24
1
biplot.princomp - changing score labels
Dear R helpers, When producing a PCA biplot, vectors of environmental variables (as red arrows with labels) and scores of the observations (black labels (observation names)) are plotted by default. How can I change the graphical output? Let's say I would like that the scores are plottet only as symbols and not text. The only solution I found was this post in the help archive
2008 Jan 18
2
plotting other axes for PCA
Hi R-community, I am doing a PCA and I need plots for different combinations of axes (e.g., PC1 vs PC3, and PC2 vs PC3) with the arrows indicating the loadings of each variables. What I need is exactly what I get using biplot (pca.object) but for other axes. I have plotted PC2 and 3 using the scores of the cases, but I don't get the arrows proportional to the loadings of each variables on
2006 Dec 18
1
Replacing labels with symbols in biplot
Dear all I would like to replace labels for x in biplot() with symbols (points) that will visually illustrate different classes/groups. After an unsuccessful search through the documents and archives, I turn to the list for help - any suggestions that can point me in the right direction? Thanks Mat Vanderklift
2009 Feb 12
1
Different labels for subsets of points in a PCA or RDA biplot
I've tried a few things both with prcomp(), and rda() and its friends in vegan (including biplot.rda and ordiplot), but can't find a solution. I'd like to associate subsets of the points in a resulting biplot ("sites" in the rda object) with different plotting colors/text styles to emphasize certain sets of points. I can't figure out how to keep the arrows (for
2010 Apr 02
2
Biplot for PCA using labdsv package
Hi everyone, I am doing PCA with labdsv package. I was trying to create a biplot graphs in order to observe arrows related to my variables. However when I run the script for this graph, the console just keep saying: *Error in nrow(y) : element 1 is empty; the part of the args list of 'dim' being evaluated was: (x)* could please someone tell me what this means? what i am doing
2012 Jun 18
2
How can I "declutter"/make a biplot less messy in R
I am doing a principle component analysis on a dataset with a lot of different variables and have constructed a biplot of the data. Unfortunately, as can be seen on the attached image, the biplot is very messy, cluttered, and hard to read. I have performed a few modifications including outlier removal from a few of the variables, which has made the plot better, however it still is too cluttered
2010 Jun 30
3
Factor Loadings in Vegan's PCA
Hi all, I am using the vegan package to run a prcincipal components analysis on forest structural variables (tree density, basal area, average height, regeneration density) in R. However, I could not find out how to extract factor loadings (correlations of each variable with each pca axis), as is straightforwar in princomp. Do anyone know how to do that? Moreover, do anyone knows
2009 Apr 28
1
colored PCA biplot
Hi- I'm trying to make my PCA (princomp) colored. In my csv excel sheet, I have the first column numbered according to the groupings I want to assign to the PCA. I've played around with trying to set this first column as the color vector, but haven't had any luck. Any suggestions? Thanks, Hillary [[alternative HTML version deleted]]
2012 Apr 20
1
Quick question about princomp/biplot
Hi everyone. I performing a simple PCA using the princomp function. Then, I use the biplot function to show it. However, the function use line number to represent samples. I would like to know if there's a way to use a dot (point) instead of the line number when using the biplot function. With regards, Phil -- View this message in context:
2012 May 07
3
How to plot PCA output?
I have a decent sized matrix (36 x 11,000) that I have preformed a PCA on with prcomp(), but due to the large number of variables I can't plot the result with biplot(). How else can I plot the PCA output? I tried posting this before, but got no responses so I'm trying again. Surely this is a common problem, but I can't find a solution with google? The University of Dundee is a
2012 Sep 09
1
PCA legend outside of PCA plot
Hi All, I have been trying to get to plot my PCA legend outside of the PCA plot, but success still alludes me. Can you guys please advise how I can achieve this. I used locater() to obtain coordinates for below the Comp.1 axis. Using these coordinates the legend disappears. Below is the code for the PCA and legend. Thanks in advance for the help. Regards Tinus r.cols <-
2007 Jun 05
2
biplot package
Dears, I've been learning biplot (Gabriel, 1971) and I found the function 'biplot', inside of the package 'stats', useful but, a bit limited. So, I'm thinking to start a colaborative package to enhance this methods to other multivariate methods. In this way, I would like to start it, making public a new function (biplot.pca, still in development, but running) that make
2008 Apr 30
3
missing values in document
No matter how I´ve tried o find a solution for this simple question, I can´t. Sorry for bothering with such a matter. I have an excel-files with some empty cells=missing values. How do I tell R that these should be NA´s? > TRFLP1 <-(read.table(file="S://SEDIM//Kokeilu//TRFLP1.txt",col.names= c("Dye_Sample Peak", "Sample_File_Name", "Size",
2011 Jun 14
1
Change Data Point Label in biplot()
I'm a new user of R, and trying to display the result of a PCA data set with biplot(). Biplot() draws the projections of data points to the first two principal axis with a text level (I guess it is the name of the data points). This makes the picture very crowed. I tried to go through R documentation to figure out how to change the data point labels to a symbol, say circle, triangle or cross
2004 Jun 29
2
Several PCA questions...
Hi, I am doing PCA on several columns of data in a data.frame. I am interested in particular rows of data which may have a particular combination of 'types' of column values (without any pre-conception of what they may be). I do the following... # My data table. allDat <- read.table("big_select_thresh_5", header=1) # Where some rows look like this... # PDB SUNID1
2012 Apr 24
2
How do i read the source code of "biplot"?
> biplot standardGeneric for "biplot" defined from package "stats" function (x, ...) standardGeneric("biplot") <environment: 0x0d4444d8> Methods may be defined for arguments: x Use showMethods("biplot") for currently available ones. > > > showMethods("biplot") Function: biplot (package stats) x="ANY"
2007 May 13
2
Biplot
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