Displaying 20 results from an estimated 6000 matches similar to: "random numbers"
2005 Jun 24
2
Gini with frequencies
Hi there,
I am trying to compute Gini coefficients for vectors containing income classes. The data I possess look loke this:
yit <- c(135, 164, 234, 369)
piit <- c(367, 884, 341, 74 )
where yit is the vector of income classes, and fit is the vector of associated frequencies.(This data is from Rustichini, Ichino and Checci (Journal of Public Economics, 1999) ). In ineq pacakge, Gini( )
2007 Jun 16
1
Use of the "by" command (clarification)
Well apparently this has nothing to do with the gini() command.
I cannot get it to work for something as simple as sum()
Here is the little example I am playing with, maybe someone can help me find
my error:
a<-c("A","B","C","A","B","C","A","A","C","B")
2016 Mar 30
2
Compute the Gini coefficient
Hello,
I would like to build a Lorenz curve and calculate a Gini coefficient in order to find how much parasites does the top 20% most infected hosts support.
Here is my data set:
Number of parasites per host:
parasites = c(0,1,2,3,4,5,6,7,8,9,10)
Number of hosts associated with each number of parasites given above:
hosts = c(18,20,28,19,16,10,3,1,0,0,0)
To represent the Lorenz curve:
I
2010 Sep 03
7
Function Gini or Ineq
Hi listers,
Does it necessary to install any package in order to use the GINI or INEQ
functions.
If I use the following command the R tells me that didn't find the GINI
function.
x<-c(541, 1463, 2445, 3438, 4437, 5401, 6392, 8304, 11904, 22261)
G<-gini(x)
Thanks in advance,
Marcio
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2005 Feb 05
2
Std Err on Concentration measures
Hi,
I'm using the ineq package to calculate some concentration measures (Gini, Herfindal, ...) and I was wondering if there's around also a function to calculate standard error on these measures. If not, is anybody aware of where I can find a reference on this point?
Thanks.
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Angelo Secchi PGP Key ID:EA280337
2007 Jun 11
1
Gini coefficient in R
If I use the Ineq library and the Gini function in this way:
>Gini(c(100,0,0,0))
I obtain the result 0.75 instead of 1 (that is the perfect inequality).
I think Gini's formula in Ineq is based on a formula as reported here:
http://mathworld.wolfram.com/GiniCoefficient.html
but in the case of perfect inequality:
x_1=.......=x_n-1 =0
x_n>0
these formula are equal to 1 - 1/n, not to
2011 Jun 13
1
In rpart, how is "improve" calculated? (in the "class" case)
Hi all,
I apologies in advance if I am missing something very simple here, but since
I failed at resolving this myself, I'm sending this question to the list.
I would appreciate any help in understanding how the rpart function is
(exactly) computing the "improve" (which is given in fit$split), and how it
differs when using the split='information' vs split='gini'
2010 Oct 19
1
Gini Coefficient
Dear List,
I am unsure if this is specifically a R question or a stats question? I thought i would ask here and if i get no replies it will answer that!
I am trying to calculate Gini coefficients in R, based on a slight modification of the typical equation that i have seen in a paper.
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2009 Sep 28
1
how to visualize gini coefficient in each node in RF?
Dear all,
I am working with randomForest package and I am interested in examining the
"Gini importance" measures that are used as a general indicator of feature
relevance. Is there a possibility of getting the Gini measure that is being
estimated in each tree by the output of the getTree() function?
Thanks a lot,
Chrysanthi
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2012 Oct 26
1
Gini with bias correction
Hey there,
I was wondering if someone could tell me if there's a package or command
that allows me to compute a GINI coefficient using a vector of weights.
Also the coefficient should be bias corrected.
Diego Rojas
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2012 Apr 18
1
Pierce's criterion
Hello all,
I would like to rigorously test whether observations in my dataset are
outliers. I guess all the main tests in R (Grubbs) impose the assumption
of normality. My data is surely not normal, so I would like to use
something else. As far as I can tell from wikipedia, Peirce's criterion is
just that.
The data I am interested in testing is: 1) Continuous on the unit interval
2)
2010 Sep 28
3
calcular la variancia de gini por bootstrap
Hola, paso el mini programita q estoy viendo, lo q me llama la atencion es
una parte donde se definen las funciones.
Probe primero meter adentro del boots la estadistica a estimar usando
directamente gini(varible, pesos) pero no me dejo.
Vi q en el ej del manual de boots, siempre define antes la funcion, entonces
probe definir antes una funcion haciendo
grini<-function(x) {gini(variable,
2001 Jan 10
1
gini index
Hi.
I have some data from a survey w/c include income data.
Was not quite sure how to generate the gini index on these
data.
Jose Ramon Albert
Statistical Research and Training Center
www.srtc.gov.ph
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Send "info",
2008 Apr 04
1
random forest varimp
Friends,
I have noticed that many publications that use RF report variable importance as
a function of mean decrease in accuracy rather than mean decrease in gini. Am I
correct that the mean decrease in accuracy is just the mean decrease in gini
divided by 100?
Thanks,
Helen Mills Poulos
Yale School of Forestry
2009 May 21
1
Rpart - best split selection for class method and Gini splitting index
Dear R-users,
I'm working with the Rpart package and trying to understand how the
procedure select the best split in the case the method "class" and the
splitting index "Gini" are used. In particular I'd like to have look to the
source code that works out the best split for un unordered predictor.
Does anyone can suggest me which functions in the sources I should
2011 Aug 26
2
How to generate a random variate that is correlated with a given right-censored random variate?
Hi,
I have a right-censored (positive) random variable (e.g. failure times subject to right censoring) that is observed for N subjects: Y_i, I = 1, 2, ..., N. Note that Y_i = min(T_i, C_i), where T_i is the true failure time and C_i is the censored time. Let us assume that C_i is independent of T_i. Now, I would like to generate another random variable U_i, I = 1, 2, ..., N, which is
2008 Sep 27
1
ariable Importance Measure in Package RandomForest
Hi,
I've a question about the RandomForest package.
The package allows the extraction of a variable importance measure. As far as
I could see from the documentation, the computation is based on the Gini index.
Do you know if this extraction can be also based on other criteria? In particular,
I'm interested in the info gain criterion.
Best regards,
Chris
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2010 Apr 08
2
C-index and Cox model
Dear all R users,
I am building a Cox PH model on a small dataset. I am wondering how to
measure the predictive power of my cox model? Normally the ROC curve or Gini
value are used in logistic regression model. Is there any similar
measurement suitable for Cox model?
Also if I use C-index statistic to measure the predictive power, is it a
time-dependent value (i.e. do I need to calculate it for
2011 Apr 02
1
uniroot speed and vectorization?
curiosity---given that vector operations are so much faster than
scalar operations, would it make sense to make uniroot vectorized? if
I read the uniroot docs correctly, uniroot() calls an external C
routine which seems to be a scalar function. that must be slow. I am
thinking a vectorized version would be useful for an example such as
of <- function(x,a) ( log(x)+x+a )
uniroot( of, c(
2008 Aug 19
2
Writing R Extensions : A new R package for Gini Index decomposition to prupose
Dear All,
I have developed a programme the anable the decomposition of the Gini index, it complets tha valuable work of Achim Zeileis, the author of the ineq package.
I would like to make it to be part of all R package. How should I proceed.
Must I sent it to the the Core developement team ?
The proogramme is written in R.
Many thanks for your advice,
Best regards,
Souleymane