search for: mpdotbook

Displaying 16 results from an estimated 16 matches for "mpdotbook".

2008 Jul 27
4
product of successive rows
Hi everyone, I want to perform an operation on a matrx that outputs the product of successive pairs of rows. For example: calculating the product between rows 1 & 2; 3 & 4; 5 & 6...etc. Does anyone know of any readily available functions that can do this? Thanks, rcoder -- View this message in context: http://www.nabble.com/product-of-successive-rows-tp18681259p18681259.html
2008 Aug 12
7
ignoring zeros or converting to NA
Hi everyone, I have a matrix that has a combination of zeros and NAs. When I perform certain calculations on the matrix, the zeros generate "Inf" values. Is there a way to either convert the zeros in the matrix to NAs, or only perform the calculations if not zero (i.e. like using something similar to an !all(is.na() construct)? Thanks, rcoder -- View this message in context:
2008 Aug 13
2
missing TRUE/FALSE error in conditional construct
Hi everyone, I posted something similar to this in reply to another post, but there seems to be a problem getting it onto the board, so I'm starting a new post. I am trying to use conditional formatting to select non-zero and non-NaN values from a matrix and pass them into another matrix. The problem is that I keep encountering an error message indicating the ":missing value where
2008 Jul 29
1
rolling regression between adjacent columns
Hi everyone, I am trying to apply linear regression to adjacent columns in a matrix (i.e. col1~col2; col3~col4; etc.). The columns in my matrix come with identifiers at the top of each column, but when I try to use these identifiers to reference the columns in the regression function using rollapply(), the columns are not recognised and the regression breaks down. Is there a more robust way to
2008 Jul 31
1
rollapply() to portions of a matrix
Hi everyone, I have a rollapply statement that applies a function, in steps, over a data matrix as follows: #Code start testm<-rollapply(mat, 100, by=100, min, na.rm=F) #Code end This moves down matrix 'mat' and calculates the minimum value over a 100 row range, every 100 rows (i.e. no overlaps). NAs are not removed. I want to modify this statement somehow so that the rollapply()
2008 Aug 13
2
merging data sets to match data to date
Hi everyone, I want to extract data from a data set according to dates specified in a vector. I have created a blank matrix with row names (dates) that I want to extract from the full data set. I have then performed a merge to try to o/p rows corresponding to common dates to a results matrix, but the operation did not fill the results matrix. Coulc anyone offer any advice to assist with this
2008 Aug 13
3
conditional IF with AND
Hi everyone, I'm trying to create an "if" conditional statement with two conditions, whereby the statement is true when condition 1 AND condition 2 are met: code structure: if ?AND? (a[x,y] <condition1>, a[x,y] <condition2>) I've trawled through the help files, but I cannot find an example of the syntax for incorporating an AND in a conditional IF statement.
2008 Aug 05
0
P values in non linear regression and singular gradients using nls
...t is > greatly appreciated. See ?subplot in the TeachingDemos package. ------------------------------ Message: 7 Date: Sun, 3 Aug 2008 10:07:24 -0400 From: "Gabor Grothendieck" <ggrothendieck at gmail.com> Subject: Re: [R] losing row.names in matrix operations To: rcoder <mpdotbook at gmail.com> Cc: r-help at r-project.org Message-ID: <971536df0808030707y3b83a302l4f56bf653971441d at mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Constructing a zoo object is well covered in ?zoo and in the three vignettes: vignette("zoo") vignette("zoo-...
2008 Aug 08
1
increment size in for loop
Hi everyone, Is there a way to vary the increment size in a for loop? For e.g. when incrementing in steps greater than unity. Thanks, rcoder -- View this message in context: http://www.nabble.com/increment-size-in-for-loop-tp18893893p18893893.html Sent from the R help mailing list archive at Nabble.com.
2008 Jul 27
0
Rolling regression - o/p selected coefficients
Hi everyone, Using the rolling regression function - rollingRegression(formula, data, width, ...) - is there a way to output only selected coefficients to a results matrix. For e.g. if I only wanted the slope coefficients to be recorded, how would I go about doing this? Thanks, Michael -- View this message in context:
2008 Jul 29
1
correlation between matrices - both with some NAs
Hi everyone, I'm having trouble applying the Cor() function to two matrices, both of which contain NAs. I am doing the following: a<-cor(m1, m2, use="complete.obs") ... and I get the following error message: Error in cor(m1, m2, use = "complete.obs") : no complete element pairs Does anyone know how I can apply a correlation, ignoring any NAs? Thanks, rcoder --
2008 Aug 07
1
long run time for loop operation & matrix fill
Hi everyone, I'm running some code containing an outer and inner loop, to fill cells in a 2500x1500 results matrix. I left my program running overnight, and it was still running when I checked 17 hours later. I have tested the operation on a smaller matrix and it executes fine, so I believe there is nothing wrong with the code. I was just wondering if this is normal program execution speed
2008 Aug 24
1
problem running dll in R
Hi everyone, I've created a dll for a fortran subroutine, and when I call the subroutine in R (via a wrapped function) a standard program shutdown windows error prompt immediately pops up: the program has encountered a problem and needs to be shut down... send message / don't send message to MS... etc. When I click "Don't send", the R consol does not then shut down, and
2008 Aug 15
2
cor() btwn columns in two matrices - no complete element pairs
Hi everyone, I'm trying to calculate correlation coefficients between corresponding columns in two matrices with identical dimensions but different data. The problem is that the matrices contain NAs in different locations. I am using the following code to try to calculate correlations between complete sets of data: #Code start maxcol<-ncol(mat1) for (i in 1:maxcol) {
2008 Aug 06
1
using acf() for multiple columns
Hi everyone, I'm trying to use the acf() function to calculate the autocorrelation of each column in a matrix. The trouble is that I can only seem to get the function to work if I extract the data in the column into a separate matrix and then apply the acf() function to this column. I have something like this: acf(mat,lag.max=10,na.action=na.pass) ...but I would really like to apply the
2008 Aug 02
1
problem with nested loop for regression
Hi everyone, I'm experiencing difficulty getting the results I want when I use a nested for loop. I have a data set to which I perform some calculations, and then try to apply a regression over a rolling window. The code runs, but the regression results I am getting (intercept and slope) are simply the same, repeated again and again in the results matrix. The regression does not seem to be