Displaying 20 results from an estimated 300 matches similar to: "Matrix Multiplication"
2009 Mar 18
2
Three Parameter FRECHET Distribution
Dear R Helpers
Which package is available for estimatine the parameters of three parameter FRECHET distribution. Also, how to generate the random numbers for Frechet using these three estimated parameters.
Thanking in advance
Maithili
2009 Aug 27
2
Comparing and adding two data series
Dear R helpers
I have two series A and B as given below -
A <- c(2, 2, 1, 3, 7, 3, 3, 1, 14, 7, 31)
B <- c(0.0728,0.9538,4.0140,0.0020,2.5593,0.1620,2.513,0.3798, .0033,0.2282, 0.1614)
I need to calculate the total in dataset B corresponding to the numbers in dataset A i.e. for no 1 in A, I need the total as 4.0140+0.3798 (as 1 is repeated twice)
for no 2, I need the total as
2009 Dec 04
2
writing 'output.csv' file
Dear R helpers
Suppose
M <- c(1:10) # length(M) = 10
N <- c(25:50) # length(N) = 26
I wish to have an outut file giving M and N. So I have tried
write.csv(data.frame(M, N), 'output.csv', row.names = FALSE)
but I get the following error message
Error in data.frame(M, N) :
arguments imply differing number of rows: 10, 26
How do I modify my write.csv
2009 Dec 01
2
Calculation of Central Moments
Dear R helpers
If for a given data, I need to calculate Mean, Standard Deviation, Mode, Median, Skewness, Kurtosis, is there any package in R, which will calculate these moments?
Individually I can calculate these, but if there is any function which will calculate these at a stretch, please let me know.
Maithili
The INTERNET now has a personality. YOURS! See your Yahoo! Homepage.
2008 Oct 07
3
How to validate model?
Hi!
I am working on scorecard model and I have arrived at the regression equation. I have used logistic regression using R.
My question is how do I validate this model? I do have hold out sample of 5000 customers.
Please guide me. Problem is I had never used Logistic regression earlier neither I am used to credit scoring models.
Thanks in advance
Maithili
2009 Aug 27
2
Fw: PROBLEM - - COMPARING AND COMBINING two DATASETS
Dear Sirs,
?
At the outset I sincerely apologize for reproducing my query to you. I also thank all of you for the solution you had provided. It has worked on the actual data I am working with.
?
However, there is this peculiar problem which I had realized only after I had obtained my results.
?
e.g. in the example I had attached
?
A?<-?c(2, 2, 1, 3, 7, 3, 3, 1,?14, 7, 31)
B?<-
2009 Mar 16
1
Fw: Fitting GUMBEL Distribution - CDF function and P P Plot
Dera R Helpers,
I am re-posting my query.
Please guide me.
Maithili
--- On Fri, 3/13/09, Maithili Shiva <maithili_shiva at yahoo.com> wrote:
I am trying to fit the Gumbel distribution to a data. I am
using lmom package. I am getting problem in Cumulative
Distribution Function of Gumbel distribution as I am getting
it as a series of 0's and 1's thereby affecting the
P P
2009 Mar 05
2
Fast Fourier Transform w.r.t. CreditRisk+
Dear R Helpers,
Is there any literaure available (including R code) on Fast Fourier Transform being used in CreditRisk+? I need to learn how to apply the Fast Fourier Transform. I agree I am too vaue in my question and sincerely apologize for the same, but I am not able to understand as to where do I start for this particular assignment. I tried to search google for CRAN and Fast Fourier
2009 Dec 24
3
An unprofessional message
Dear R helpers,
I understand that this is absolutely unprofessional on my part and this group doesn't entertain such things. I have been associted with this group since last 1 and half years and have been immensely benefited by the noble service rendred by many R helpers.
So I take this opportunity to thank all of you and wish you all
"MERRY CHRISTMAS".
I sincerely apologize
2009 Jan 08
2
VaR-Monte carlo Simulation, Historic simulation, Variance-Covariance Simulation
Dear R helpers
Suppose I have a portfolio of securities with exposure to Equity, Bonds and Forex (say $ 1000000 each).
Is there any fucntion in R that will help me calculate Value at Risk (VaR) using Monte carlo Simulation , Historic simulation and Variance - Covariance Simulation.
With regards
Maithili
2008 Dec 18
1
Random Number Generation using (Generalized) Extreme Value distribution and Pareto distribution
Hi R helpers,
Is there any function in R, which generates random numbers in case of
(1) Generalized Extreme Value distribution and
(2) Generalized PAreto distribution for the respective given set of parameters?
Regards
Maithili
2009 Feb 11
1
Generating Correlation matrix
Dear R helpers,
I have generated a portfolio of Equity, Dollar Rate and say zero coupon bond. I have calculated the daily returns based on the prices available for last two years.
Now, I have three seperate csv files (Equity.csv, Dollar.csv and Bond.csv) containing the respective returns. I need to calculate the correlation matrix between the retuns of these assets. Please guide me how this
2009 Oct 07
1
Parameters of Beta distribution
Supose I have a data pertaining to credit loss as
amounts <- c(46839.50,31177.12,35696.69,21192.57,29200.91,42049.64,42422.19, 44976.18, 32135.36,47936.57,27322.91,37359.09,43179.60, 48381.02, 45872.38, 28057.30,44643.83,36156.33,16037.62, 45432.28)
I am trying to fit Beta distribution (two parameters distribution but where lower bound and upper bounds are NOT 0 and 1 respectively). For
2009 Dec 26
1
Reading Input file
Dear R helpers
I have some files in my say 'WORK' directory and the file names are say rate1.csv, rate2.csv, rate3.csv, rate4.csv
Because of some other requirement, I need to run the following commands
n = 4
rates = NULL
for (i in 1:n)
rates[i] = (paste(`rate', i, ‘.csv`, sep = ‘’))
# this gives me "rate1.csv" "rate2.csv" and so on
#My problem is
2009 May 27
1
How to write a loop?
Dear R helpers,
Following is a R script I am using to run the Fast Fourier Transform. The csv files has 10 columns with titles m1, m2, m3 .....m10.
When I use the following commands, I am getting the required results. The probelm is if there are 100 columns, it is not wise to define 100 commands as fk <- ONS$mk and so on. Thus, I need some guidance to write the loop for the STEP A and
2009 Dec 17
1
CORRECTION - Generation of Random numbers in a loop
Dear R helpers, please ignore my earlier mail. Here is the corrected mail. Please forgive me for the lapses on my part. Extremely sorry.
Here is the corrected mail.
Dear R helpers
I am having following data
Name Numbers
A11 12
A12 17
A13 0
A11 11
A12 6
A13 0
2009 Dec 15
2
Random numbers for a group
Dear R helpers
I have following table
Name no_of_instances
AAA 12
AA 17
A 0
BBB 11
BB
2008 Oct 13
4
Fw: Logistic regresion - Interpreting (SENS) and (SPEC)
Dear Mr Peter Dalgaard and Mr Dieter Menne,
I sincerely thank you for helping me out with my problem. The thing is taht I already have calculated SENS = Gg / (Gg + Bg) = 89.97%
and SPEC = Bb / (Bb + Gb) = 74.38%.
Now I have values of SENS and SPEC, which are absolute in nature. My question was how do I interpret these absolue values. How does these values help me to find out wheher my model is
2009 Dec 21
2
Reading multiple Input Files
Dear R helpers,
Suppose I am dealing with no of interest rates at a time and the no of interest rates I am selecting for my analysis is random i.e. it can be 2, can be 10 or even higher. The R-code I had written (with the guidance of R helpers obviously and I am really grateful to all of you) as of now is sort of hard coding when it comes to reading interest rates as an input e.g.
## INPUT
2008 Dec 10
1
Stepwise regression
Hi,
I have the response variable 'Y' and four predictors say X1, X2, X3 and X4. Assuming all the assmptions like Y follows normal distribution etc. hold and I want to run linear multiple regression. How do I run the stepwise regression (forward as well as the backward regression).
>From other software (i.e. minitab), I know only X1 and X2 are significant so my regression equation