FreeStatistics.org

Free Statistics

of Irreproducible Research!

Description of Statistical Computation

Author's title

Author*The author of this computation has been verified*
R Software Modulerwasp_bootstrapplot.wasp
Title produced by softwareBlocked Bootstrap Plot - Central Tendency
Date of computationThu, 30 Oct 2008 07:46:38 -0600
Cite this page as followsStatistical Computations at FreeStatistics.org, Office for Research Development and Education, URL https://freestatistics.org/blog/index.php?v=date/2008/Oct/30/t1225374582yqtczgb8nszxkjq.htm/, Retrieved Tue, 14 May 2024 06:24:26 +0000
Statistical Computations at FreeStatistics.org, Office for Research Development and Education, URL https://freestatistics.org/blog/index.php?pk=20036, Retrieved Tue, 14 May 2024 06:24:26 +0000
QR Codes:

Original text written by user:
IsPrivate?No (this computation is public)
User-defined keywords
Estimated Impact196

Tree of Dependent Computations

Family? (F = Feedback message, R = changed R code, M = changed R Module, P = changed Parameters, D = changed Data)
F     [Blocked Bootstrap Plot - Central Tendency] [workshop 3] [2007-10-26 12:36:24] [e9ffc5de6f8a7be62f22b142b5b6b1a8]
F    D    [Blocked Bootstrap Plot - Central Tendency] [Hypothesis Testin...] [2008-10-30 13:46:38] [284c7cdb9fcda2adcbb08e211682c8d6] [Current]
F    D      [Blocked Bootstrap Plot - Central Tendency] [Hypothesis Testin...] [2008-11-02 13:43:40] [d32f94eec6fe2d8c421bd223368a5ced]
Feedback Forum
2008-11-06 13:54:29 [Nathalie Koulouris] [reply] 
De student heeft deze vraag correct opgelost. Men moet de midrange dus als gemiddelde nemen omdat daar de spreiding het kleinst is.
2008-11-06 17:46:44 [Romina Machiels] [reply] 
Hij heeft de vraag goed beantwoord.
2008-11-07 14:29:50 [Jeroen Aerts] [reply] 
Je kan hier eigenlijk kiezen wat het beste gemiddelde is, het is een persoonlijke keuze. Want als je de midrange neemt als gemiddelde, heb je de kleinste variantie, maar heb je veel notches bij Bootstrap simulation - Central tendency.
2008-11-07 15:17:25 [Mehmet Yilmaz] [reply] 
De student geeft een correct antwoord.
2008-11-08 14:58:56 [Kim Huysmans] [reply] 
Het antwoord van de student is correct. Als gemiddelde kunnen we het beste de midrange nemen. Hier is de spreiding (of variantie) het kleinst. Maar de midrange is wel gevoelig voor outliers. Omdat deze outliers een probleem kunnen vormen kan je ook kiezen voor de mean. Hier is de spreiding dan wel groter, maar er zijn geen outliers dus is het gemiddelde iets zekerder. Beide antwoorden zijn correct.

2008-11-11 12:02:23 [Jeroen Michel] [reply] 
De student geeft een juiste weergave met correcte conclusies.

Hieronder vindt u nogmaals een theoretische weergave weer:
Bootstrapping: gem. Dataset ïƒ 500 x opnieuw
Telkens 1 eruit nemen en een andere terugleggen ( er bestaat dan natuurlijk de kans dat je hetzelfde terug neemt)
Simulation of mean: Alle punten zijn alle berekende gemiddelden, door elkaar.
Simulation of median: meer een patroon
Imulation of midrange: duidelijk patroon
Hoe minder variatie, hoe nauwkeuriger
Midrange als gemiddelde nemen omdat daar de variatie het kleinst is
Maar: daar zijn wel heel veel outliers!!! Je hebt een gemiddelde waarvan de getrouwheidsinterval zeer klein is, maar als je er buiten zit, zit je er wel extreem buiten. Je moet maw zelf een overweging doen. Dwz dat de mean ook goed kan zijn. Het heeft een groter getrouwheidsinterval, maar de outliers zijn minder extreem.
De punten op de grafiek zij gemiddelden, dus je kan ze niet vinden in je dataset
Outliers zijn dus WEL relevant! .. ze bepalen de keuze, MAAR het gaat over gemiddelden

Post a new message

Dataset

Dataseries X:
Download CSV
Histogram
Boxplots 
109.20
88.60
94.30
98.30
86.40
80.60
104.10
108.20
93.40
71.90
94.10
94.90
96.40
91.10
84.40
86.40
88.00
75.10
109.70
103.00
82.10
68.00
96.40
94.30
90.00
88.00
76.10
82.50
81.40
66.50
97.20
94.10
80.70
70.50
87.80
89.50
99.60
84.20
75.10
92.00
80.80
73.10
99.80
90.00
83.10
72.40
78.80
87.30
91.00
80.10
73.60
86.40
74.50
71.20
92.40
81.50
85.30
69.90
84.20
90.70
100.30

Tables (Output of Computation)





Summary of computational transaction
Raw Inputview raw input (R code)
Raw Outputview raw output of R engine
Computing time6 seconds
R Server'George Udny Yule' @ 72.249.76.132

\begin{tabular}{lllllllll}
\hline
Summary of computational transaction \tabularnewline
Raw Input & view raw input (R code)  \tabularnewline
Raw Output & view raw output of R engine  \tabularnewline
Computing time & 6 seconds \tabularnewline
R Server & 'George Udny Yule' @ 72.249.76.132 \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=20036&T=0

[TABLE]
[ROW][C]Summary of computational transaction[/C][/ROW]
[ROW][C]Raw Input[/C][C]view raw input (R code) [/C][/ROW]
[ROW][C]Raw Output[/C][C]view raw output of R engine [/C][/ROW]
[ROW][C]Computing time[/C][C]6 seconds[/C][/ROW]
[ROW][C]R Server[/C][C]'George Udny Yule' @ 72.249.76.132[/C][/ROW]
[/TABLE]
Source: https://freestatistics.org/blog/index.php?pk=20036&T=0

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=20036&T=0

As an alternative you can also use a QR Code:  
QR Code


The GUIDs for individual cells are displayed in the table below:

Summary of computational transaction
Raw Inputview raw input (R code)
Raw Outputview raw output of R engine
Computing time6 seconds
R Server'George Udny Yule' @ 72.249.76.132






Estimation Results of Blocked Bootstrap
statisticQ1EstimateQ3S.D.IQR
mean85.64139344262386.893442622950888.01229508196721.684946347774092.37090163934427
median86.487.3881.893262593116171.59999999999999
midrange88.188.188.851.036344638824770.75

\begin{tabular}{lllllllll}
\hline
Estimation Results of Blocked Bootstrap \tabularnewline
statistic & Q1 & Estimate & Q3 & S.D. & IQR \tabularnewline
mean & 85.641393442623 & 86.8934426229508 & 88.0122950819672 & 1.68494634777409 & 2.37090163934427 \tabularnewline
median & 86.4 & 87.3 & 88 & 1.89326259311617 & 1.59999999999999 \tabularnewline
midrange & 88.1 & 88.1 & 88.85 & 1.03634463882477 & 0.75 \tabularnewline
\hline
\end{tabular}
%Source: https://freestatistics.org/blog/index.php?pk=20036&T=1

[TABLE]
[ROW][C]Estimation Results of Blocked Bootstrap[/C][/ROW]
[ROW][C]statistic[/C][C]Q1[/C][C]Estimate[/C][C]Q3[/C][C]S.D.[/C][C]IQR[/C][/ROW]
[ROW][C]mean[/C][C]85.641393442623[/C][C]86.8934426229508[/C][C]88.0122950819672[/C][C]1.68494634777409[/C][C]2.37090163934427[/C][/ROW]
[ROW][C]median[/C][C]86.4[/C][C]87.3[/C][C]88[/C][C]1.89326259311617[/C][C]1.59999999999999[/C][/ROW]
[ROW][C]midrange[/C][C]88.1[/C][C]88.1[/C][C]88.85[/C][C]1.03634463882477[/C][C]0.75[/C][/ROW]
[/TABLE]
Source: https://freestatistics.org/blog/index.php?pk=20036&T=1

Globally Unique Identifier (entire table): ba.freestatistics.org/blog/index.php?pk=20036&T=1

As an alternative you can also use a QR Code:  
QR Code


The GUIDs for individual cells are displayed in the table below:

Estimation Results of Blocked Bootstrap
statisticQ1EstimateQ3S.D.IQR
mean85.64139344262386.893442622950888.01229508196721.684946347774092.37090163934427
median86.487.3881.893262593116171.59999999999999
midrange88.188.188.851.036344638824770.75


Figures (Output of Computation)

Input Parameters & R Code

Parameters (Session):
par1 = 500 ; par2 = 12 ;
Parameters (R input):
par1 = 500 ; par2 = 12 ; par3 = ; par4 = ; par5 = ; par6 = ; par7 = ; par8 = ; par9 = ; par10 = ; par11 = ; par12 = ; par13 = ; par14 = ; par15 = ; par16 = ; par17 = ; par18 = ; par19 = ; par20 = ;
R code (references can be found in the software module):
par1 <- as.numeric(par1)
par2 <- as.numeric(par2)
if (par1 < 10) par1 = 10
if (par1 > 5000) par1 = 5000
if (par2 < 3) par2 = 3
if (par2 > length(x)) par2 = length(x)
library(lattice)
library(boot)
boot.stat <- function(s)
{
s.mean <- mean(s)
s.median <- median(s)
s.midrange <- (max(s) + min(s)) / 2
c(s.mean, s.median, s.midrange)
}
(r <- tsboot(x, boot.stat, R=par1, l=12, sim='fixed'))
bitmap(file='plot1.png')
plot(r$t[,1],type='p',ylab='simulated values',main='Simulation of Mean')
grid()
dev.off()
bitmap(file='plot2.png')
plot(r$t[,2],type='p',ylab='simulated values',main='Simulation of Median')
grid()
dev.off()
bitmap(file='plot3.png')
plot(r$t[,3],type='p',ylab='simulated values',main='Simulation of Midrange')
grid()
dev.off()
bitmap(file='plot4.png')
densityplot(~r$t[,1],col='black',main='Density Plot',xlab='mean')
dev.off()
bitmap(file='plot5.png')
densityplot(~r$t[,2],col='black',main='Density Plot',xlab='median')
dev.off()
bitmap(file='plot6.png')
densityplot(~r$t[,3],col='black',main='Density Plot',xlab='midrange')
dev.off()
z <- data.frame(cbind(r$t[,1],r$t[,2],r$t[,3]))
colnames(z) <- list('mean','median','midrange')
bitmap(file='plot7.png')
boxplot(z,notch=TRUE,ylab='simulated values',main='Bootstrap Simulation - Central Tendency')
grid()
dev.off()
load(file='createtable')
a<-table.start()
a<-table.row.start(a)
a<-table.element(a,'Estimation Results of Blocked Bootstrap',6,TRUE)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'statistic',header=TRUE)
a<-table.element(a,'Q1',header=TRUE)
a<-table.element(a,'Estimate',header=TRUE)
a<-table.element(a,'Q3',header=TRUE)
a<-table.element(a,'S.D.',header=TRUE)
a<-table.element(a,'IQR',header=TRUE)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'mean',header=TRUE)
q1 <- quantile(r$t[,1],0.25)[[1]]
q3 <- quantile(r$t[,1],0.75)[[1]]
a<-table.element(a,q1)
a<-table.element(a,r$t0[1])
a<-table.element(a,q3)
a<-table.element(a,sqrt(var(r$t[,1])))
a<-table.element(a,q3-q1)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'median',header=TRUE)
q1 <- quantile(r$t[,2],0.25)[[1]]
q3 <- quantile(r$t[,2],0.75)[[1]]
a<-table.element(a,q1)
a<-table.element(a,r$t0[2])
a<-table.element(a,q3)
a<-table.element(a,sqrt(var(r$t[,2])))
a<-table.element(a,q3-q1)
a<-table.row.end(a)
a<-table.row.start(a)
a<-table.element(a,'midrange',header=TRUE)
q1 <- quantile(r$t[,3],0.25)[[1]]
q3 <- quantile(r$t[,3],0.75)[[1]]
a<-table.element(a,q1)
a<-table.element(a,r$t0[3])
a<-table.element(a,q3)
a<-table.element(a,sqrt(var(r$t[,3])))
a<-table.element(a,q3-q1)
a<-table.row.end(a)
a<-table.end(a)
table.save(a,file='mytable.tab')