[R] loop

Wed Oct 13 21:48:31 CEST 2010

Julia -
    Your subscript is out of range because in this loop:

     for (t in aeven2){
         Mhb0[,t] <- M[,(41+t)]-M[,(41-t)]
         Mhb1[,t] <- M[,(42+t)]-M[,(42-t)]
        }

t takes the values from 2 to 40 by 2, and you've
declared Mhb0 and Mhb1 as matrices with 20 columns.
So when t reaches 22, there is no corresponding 
column in Mhb0 or Mhb1.

 					- Phil Spector
 					 Statistical Computing Facility
 					 Department of Statistics
 					 UC Berkeley
 					 spector at stat.berkeley.edu

On Wed, 13 Oct 2010, Julia Lira wrote:

>
> Dear Eriki and all
>
>
>
> To run Quantile regression, it is necessary to install the following package in R:
>
>
>
> install.packages("quantreg")
>
>
>
> Then, write:
>
>
>
> library(quantreg)
>
>
>
> And the software will run.
>
>
>
> rm(list=ls()) #remove almost everything in the memory
>
> set.seed(180185)
> nsim <- 10
> mresultx <- matrix(-99, nrow=1000, ncol=nsim)
> mresultb <- matrix(-99, nrow=1000, ncol=nsim)
> N <- 200
> I <- 5
> taus <- c(0.480:0.520)
> h <- c(1:20/1000)
> alpha1 <- c(1:82)
> aeven1 <- alpha1[2 * 1:41]
> aodd1 <- alpha1[-2 * 1:41]
> alpha2 <- c(1:40)
> aeven2 <- alpha2[2 * 1:20]
> #Create an object to hold results.
> M <- matrix(0, ncol=82, nrow=nsim)
> Mhb0 <- matrix(0, ncol=20, nrow=nsim)
> Mhb1 <- matrix(0, ncol=20, nrow=nsim)
> Mchb0 <- matrix(0, ncol=20, nrow=nsim)
> Mchb1 <- matrix(0, ncol=20, nrow=nsim)
> for (i in 1:nsim){
> # make a matrix with 5 cols of N random uniform values
> u <- replicate( 5, runif(N, 0, 1) )
> # fit matrix u in another matrix of 1 column
> mu <- matrix(u, nrow=1000, ncol=1)
> # make auction-specific covariate
> x <- runif(N, 0, 1)
> mx <- matrix(rep(x,5), nrow=1000, ncol=1)
> b0 <- matrix(rep(c(1),1000), nrow=1000, ncol=1)
> #function for private cost
> cost <- b0+b0*mx+mu
> #bidding strategy
> bid <- mx+((I+1)/I)+((I-1)/I)*mu
> mresultb[,i] <- bid
> mresultx[,i] <- mx
> qf <- rq(formula = mresultb[,i] ~ mresultx[,i], tau= 480:520/1000)
> # Storing result and does not overwrite prior values
> M[i, ] <- coef(qf)
> QI <- (1-0.5)/(I-1)
> M50b0 <- M[,41]
> M50b1 <- M[,42]
> Mb0 <- matrix(M[,aodd1], nrow=nsim, ncol=20)
> Mb1 <- matrix(M[,aeven1], nrow=nsim, ncol=20)
> for (t in aeven2){
> Mhb0[,t] <- M[,(41+t)]-M[,(41-t)]
> Mhb1[,t] <- M[,(42+t)]-M[,(42-t)]
> }
> }
>
>
>
> Here, the matrix M stores the result for all quantiles (by column) considering each simulation i (by row).
>
> Then, I try to make some algebric simulations. I need to calculate Mhb0 such that for each value of t, the column called t in matrix Mhb0 will be the result of the subtraction of column (41-t) from the column (41+t) of the matrix M. To be more precise:
>
>
>
> for t = 2, 4, 6,...
>
>
>
> Mhb0 will be a matrix such that in the first column I will have {column (41+t) of M - column (41-t) of M}
>
> This should be the loop, and I would have 20 column for all the even number from 2 to 82 (specified in aeven2).
>
>
>
> Is that clear now? But the software says: "Error in Mhb0[, t] <- M[, (41 + t)] - M[, (41 - t)] :   subscript out of bounds"
>
>
>
> What am I doing wrong?
>
>
>
> Thanks a lot!
>
>
>
> Julia
>
>
>
>> Date: Wed, 13 Oct 2010 13:53:28 -0500
>> From: eriki at ccbr.umn.edu
>> To: julia.lira at hotmail.co.uk
>> CC: r-help at r-project.org
>> Subject: Re: [R] loop
>>
>> Julia,
>>
>> Can you provide a reproducible example? Your code calls the
>> 'rq' function which is not found on my system.
>>
>> Any paring down of the code to make it more readable would
>> help us help you better, too.
>>
>>
>> Julia Lira wrote:
>>> Dear all,
>>>
>>>
>>>
>>> I am trying to run a loop in my codes, but the software returns an error: "subscript out of bounds"
>>>
>>>
>>>
>>> I dont understand exactly why this is happenning. My codes are the following:
>>>
>>>
>>>
>>> rm(list=ls()) #remove almost everything in the memory
>>>
>>> set.seed(180185)
>>> nsim <- 10
>>> mresultx <- matrix(-99, nrow=1000, ncol=nsim)
>>> mresultb <- matrix(-99, nrow=1000, ncol=nsim)
>>> N <- 200
>>> I <- 5
>>> taus <- c(0.480:0.520)
>>> h <- c(1:20/1000)
>>> codd <- c(1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35,37,39,41,43,45,47,49,51,53,55,57,59,61,63,65,67,69,71,73,75,77,79,81)
>>> ceven <- c(2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46,48,50,52,54,56,58,60,62,64,66,68,70,72,74,76,78,80,82)
>>> cevenl <- c(2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40)
>>> #Create an object to hold results.
>>> M <- matrix(0, ncol=82, nrow=nsim)
>>> Mhb0 <- matrix(0, ncol=20, nrow=nsim)
>>> Mhb1 <- matrix(0, ncol=20, nrow=nsim)
>>> Mchb0 <- matrix(0, ncol=20, nrow=nsim)
>>> Mchb1 <- matrix(0, ncol=20, nrow=nsim)
>>> for (i in 1:nsim){
>>> # make a matrix with 5 cols of N random uniform values
>>> u <- replicate( 5, runif(N, 0, 1) )
>>> # fit matrix u in another matrix of 1 column
>>> mu <- matrix(u, nrow=1000, ncol=1)
>>> # make auction-specific covariate
>>> x <- runif(N, 0, 1)
>>> mx <- matrix(rep(x,5), nrow=1000, ncol=1)
>>> b0 <- matrix(rep(c(1),1000), nrow=1000, ncol=1)
>>> #function for private cost
>>> cost <- b0+b0*mx+mu
>>> #bidding strategy
>>> bid <- mx+((I+1)/I)+((I-1)/I)*mu
>>> mresultb[,i] <- bid
>>> mresultx[,i] <- mx
>>> qf <- rq(formula = mresultb[,i] ~ mresultx[,i], tau= 480:520/1000)
>>> # Storing result and does not overwrite prior values
>>> M[i, ] <- coef(qf)
>>> QI <- (1-0.5)/(I-1)
>>> M50b0 <- M[,41]
>>> M50b1 <- M[,42]
>>> Mb0 <- matrix(M[,codd], nrow=nsim, ncol=20)
>>> Mb1 <- matrix(M[,ceven], nrow=nsim, ncol=20)
>>> for (t in cevenl){
>>> Mhb0[ ,t] <- M[,(41+t)]-M[,(41-t)]
>>> Mhb1[ ,t] <- M[,(42+t)]-M[,(42-t)]
>>> }
>>> }
>>>
>>>
>>>
>>> Problem: the problem is in the red part of the loop. I want that the software takes the column (41+t) from the matrix called M and subtract from it the cloumn (41-t) of the same matrix M, such that the value of t varies according to the vector cevenl above.
>>>
>>>
>>>
>>> Why is this looping not working?
>>>
>>>
>>>
>>> Thanks in advance!!!
>>>
>>>
>>>
>>> Julia
>>>
>>> [[alternative HTML version deleted]]
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>