InfoVis:Wiki - User contributions [en]

User:UE-InfoVis0708 8007433

2008-11-23T01:22:03Z

UE-InfoVis0708 8007433:

Gruppe: [[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05]] 
UE-Home: [[Teaching:TUW_-_UE_InfoVis_WS_2007/08]]

Teaching talk:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 3

2008-02-05T18:33:26Z

UE-InfoVis0708 8007433: persönliche Kommentare von Johann Petrak zur Bewertung

== Bewertung ==

<strike>'''Punkte: 13 von 25'''</strike>

'''Begründung:'''

siehe Kommentare (kursiv) bei [[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 3|Aufgabe 3]]

'''''Ihr habt die Möglichkeit, die angegebenen Dinge noch bis einschließlich 15.01.2008 zu verbessern - dann wird natürlich eure Punkteanzahl aufgewertet!'''''

-- [[User:ASchratt|Alexander Schratt]] 17:13, 20 December 2007 (CEST)

- Die Prozentangaben innerhalb der Balken sind viel zu dominant und eigentlich auch unnötig. 
- Im Grunde geht es bei den Daten hier um den Vergleich von zwei Verteilungen und ich bin skeptisch, 
ob die gewählte Darstellung dafür geeignet ist. In der jetzigen Darstellung kann man gut 
die einzelnen Balken vergleichen, was aber nicht wirklich Sinn macht, von den Daten her. 
- Was meiner Meinung nach besser geeignet wäre, weil man die globale Form besser vergleich kann, 
wäre etwas in dieser Richtung: 
(z.B. links West, rechts Ost) 
XXXXXX|0000 
XXXX|000000 
XX|000 
XXXX|0000 

- Außerdem: Vertikale Beschriftung der Werteskala ist zu vermeinden bzw. sollten 
die Prozentzeichen auch in der Skala enthalten sein.

: Damit kann ich überhaupt nicht übereinstimmen: Ich finde, dass die Vergleichbarkeit der einzelnen Sparten - und darum geht es meines Erachtens primär, mit dieser Lösung weitaus besser realisiert ist, als mit der vorgeschlagenen gespiegelten Lösung, die zwar die globale Form besser darstellt, aber wie ich denke nicht um so viel besser, wie sie den Vergleich der Sparten schlechter darstellt. Es dürfte daher also auf den Zusammenhang und die Aussage ankommen, die im Text, der die Grafik begleitete, gemacht wurde, und der stand ja nicht zur Verfügung.

: Mir ist ehrlich gesagt auch nicht klar was "viel zu dominant" heissen soll -- gibt es dafür einen wissenschaftlich fundierten Standard oder ist das Geschmacksache, künstlerisches Augenmaß? Ich würde das als gut sichtbar, auch für meine nicht so guten Augen, bezeichnen. Überhaupt kommt es ja letztendlich auf die endgültige Größe/Skalierung der Grafik auf einem Ausgabemdium an. Von der Bedeutung her sind jedenfals diese Zahlen das Essentielle.

: Was die Prozentangaben in der vertikalen Skala betrifft ist eine Angabe des Prozentzeichens (so wie die Angabe von Einheiten bei jedem Wert) meines Erachtens unnötige Tinte wenn es sich leicht oder sofort aus dem Zusammenhang ergibt - was bei dieser Grafik zugegebenermaßen nicht wirklich der Fall ist -- man hätte vielleicht die Achse oder dir Grafik noch mit "in %" beschriften sollen. Und warum zwar eine Y-Achse mit Tickmarks gezeigt werden soll, aber dann nicht entsprechend beschriftet ist für mich ehrlich gesagt gar nicht nachzuvollziehen.

: [[User:UE-InfoVis0708 8007433|UE-InfoVis0708 8007433]] 19:33, 5 February 2008 (CET)

'''Punkte neu: 20 von 25'''

-- [[User:ASchratt|Alexander Schratt]] 15:55, 05 February 2008 (CEST)

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 3

2008-01-15T16:43:07Z

UE-InfoVis0708 8007433:

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 3

2008-01-13T17:03:20Z

UE-InfoVis0708 8007433: R-code for the modified graph

== Poor Graphic ==
[http://ieg.ifs.tuwien.ac.at/~aigner/teaching/infovis_ue/infovis_ue_aufgabe3.html Beschreibung der Aufgabe 3]

[[Image:Besucherverteilung.jpg]]
Besucherverteilung West - Ost

== Review ==

* The essential data values are hidden in the labels that are scattered in small print all over the graph.
* The graphical representation of the data is hard to impossible to grasp: one can suspect that the height of the circular stairs are supposed to be proportional to the percentage. However, there is no reason, why there should be 3D stairs, and even less why those stairs should be circual.
* The pictorial illustration of the different performance types hides the data-related parts of the graph and unnecessary complex as a visual way to distinguish between performance types. In combination with a better graph, and done in a less complex way, such icons could be useful though since they do allow an immediate association of the performace type and are - in comparison to color coding - accessible for color-blind people.

''Diese Piktogramme (Icons) sind absolut überflüssig. Abgesehen davon, dass die Symbolik missverständlich sein kann (und auch ist), reicht die Beschriftung vollkommen aus. Die Piktogramme sind somit redundante Information und erzeugen nur visual clutter.''

* Overall, data-ink ration on this graph is very low: apart from all the ink-consuming 3D shading, the actual data can really just be gathered from the percentage given in the label texts.
* Organization of the graph into two halves for east/west comparison is good, but to display the data values for each half as rounded stairs makes it extremely difficult to get an impression of the actual distributions.
* Another problem is that the percentage for "Kinder und Jugendthater" is given separately for "West" but is combined with "Schauspiel" for "Ost".
* The values are given sometimes with one digit after the comma for east, but with no digit after the comma for west data.
* It is not clear what the actual source of the data is. The text to the left of the chart hints towards the "Bundesministerium für innerdeutsche Beziehungen" but what has the Promot GmbH got to do with it? What does the "75" in "Quellen" mean and what are the "eigene Berechnungen"?
''Sehr gute Beobachtung!''

== Revised diagram ==
[[Image:West_ost04.png]]
== Explanation of changes ==

* The percentage of "Kinder und Jugendtheater" has been combined with "Schauspiel" for "West" too, so that the comparison is made more easy.
* The percentages for "West" and "Ost" are displayed in a standard form for percentages: a stacked bar chart for each of West and Ost (an alternative would have been to use two pie charts, but we believe the data stands out more directly in the stacked bar chart).

''Bei relativen Darstellungen sind nach S. Few "stacked bar charts" zu vermeiden (Ausnahmefall: Absolute Werte werden durch die Höhe des Balkens dargestellt (Primäraussage) und relative Werte (Sekundäraussage) anteilsmäßig auf den Balken übertragen.)'' 
''Stattdessen wären zur besseren Vergleichbarkeit die Balken nebeneinander zu stellen.'' 

''Neben einer Basislinie (X-Achse) sollte eine Y-Achse mit Tick Marks eingeführt werden.'' 

''Pie Charts sind nach Few zu vermeiden, da sie schlechter interpretierbar sind als Bar Charts.''

* The different categories per chart are coded using color. The color coding was chosen so that red-green blind people (most frequent color blindness) can see the chart easily too.

''Warum verwendet ihr dann Rot / Grün!

* The labeling of the categories was done using the text only, the icons were doropped
* Y-axis has been left out since it does not convey any relevant information

''Dennoch wäre bei vertikalen Balken eine Basislinie zu zeichnen, damit nicht der Eindruck entsteht, 
die Balken würden "in der Luft hängen (vgl. S. Few)."

* Values for east have been rounded to the next integer percentage value since values for west are only exact to whole percentage points too.
* The year for the comparison is assumed to be 1988, the source is given based on assumptions. If this is not clear, it would be better to not use the data at all.

''Die Daten beziehen sich auf 1982 (siehe unterhalb des Titels in der Originalgrafik - leicht zu übersehen): Besucherverteilung 1982 in %).''

''Konturen um die Balken herum sind eigentlich nicht notwendig''

''Sonstiges (die Originalgrafik betreffend):'' 
''- Reihenfolge Oper&Balett / Oper&Musical ist unterschiedlich.'' 
''- Quellenangaben sind auf den linken Rand und unteren rechten Bereich aufgeteilt > gehören zusammen.'' 
''- Titel befindet sich in der Datenegion; ist nicht klar von den Daten separiert.'' 
''- Hingegen befinden sich die Kategorien Ost - West im Titelbereich.'' 

== R-code to generate the graph ==

makepng<-function() {
png("West_ost04.png",bg="transparent",width=700,height=700)
makegraph()
dev.off()
}
makegraph<-function() {
west= c(60,21,10,9)
ost = c(41,16,20,23)
l = c("Schauspiel","Oper/Ballett","Operette/Musical","Sonstige")
m=matrix(c(west,ost),ncol=2)
m=t(m)
bs=barplot(m,beside=TRUE,names=l,legend.text=c("West","Ost"),cex.names=1.5,space=c(0,0.3))
for(i in 1:4) {
text(bs[1,i],5,paste(west[i],"%",sep=""),adj=0.5,cex=2,col="white")
text(bs[2,i],5,paste(ost[i], "%",sep=""),adj=0.5,cex=2)
}
lines(c(-3,10),c(0,0))
title(main = "Besucherverteilung West/Ost 1982", sub="Zahlenspiegel, Bundesministerium für innerdeutsche Beziehungen")
}

== Links ==

* [[Teaching:TUW_-_UE_InfoVis_WS_2007/08|InfoVis:Wiki UE Homepage]]

* [http://ieg.ifs.tuwien.ac.at/~aigner/teaching/infovis_ue/index.html UE InfoVis]

*[[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05|Gruppe 05]]

File:West ost04.png

2008-01-13T17:01:37Z

UE-InfoVis0708 8007433: New page: == Summary == == Copyright status == graphic: public domain, contained data: unknown == Source ==

== Summary ==

== Copyright status ==
graphic: public domain, contained data: unknown
== Source ==

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 3

2007-12-08T19:08:47Z

UE-InfoVis0708 8007433:

== Poor Graphic ==
[http://ieg.ifs.tuwien.ac.at/~aigner/teaching/infovis_ue/infovis_ue_aufgabe3.html Beschreibung der Aufgabe 3]

[[Image:Besucherverteilung.jpg]]
Besucherverteilung West - Ost

== Review ==

* The essential data values are hidden in the labels that are scattered in small print all over the graph.
* The graphical representation of the data is hard to impossible to grasp: one can suspect that the height of the circular stairs are supposed to be proportional to the percentage. However, there is no reason, why there should be 3D stairs, and even less why those stairs should be circual.
* The pictorial illustration of the different performance types hides the data-related parts of the graph and unnecessary complex as a visual way to distinguish between performance types. In combination with a better graph, and done in a less complex way, such icons could be useful though since they do allow an immediate association of the performace type and are - in comparison to color coding - accessible for color-blind people.
* Overall, data-ink ration on this graph is very low: apart from all the ink-consuming 3D shading, the actual data can really just be gathered from the percentage given in the label texts.
* Organization of the graph into two halves for east/west comparison is good, but to display the data values for each half as rounded stairs makes it extremely difficult to get an impression of the actual distributions.
* Another problem is that the percentage for "Kinder und Jugendthater" is given separately for "West" but is combined with "Schauspiel" for "Ost".
* The values are given sometimes with one digit after the comma for east, but with no digit after the comma for west data.
* It is not clear what the actual source of the data is. The text to the left of the chart hints towards the "Bundesministerium für innerdeutsche Beziehungen" but what has the Promot GmbH got to do with it? What does the "75" in "Quellen" mean and what are the "eigene Berechnungen"?

== Revised diagram ==
[[Image:West_ost03.png]]
== Explanation of changes ==

* The percentage of "Kinder und Jugendtheater" has been combined with "Schauspiel" for "West" too, so that the comparison is made more easy.
* The percentages for "West" and "Ost" are displayed in a standard form for percentages: a stacked bar chart for each of West and Ost (an alternative would have been to use two pie charts, but we believe the data stands out more directly in the stacked bar chart).
* The different categories per chart are coded using color. The color coding was chosen so that red-green blind people (most frequent color blindness) can see the chart easily too.
* The labeling of the categories was done using the text only, the icons were doropped
* Y-axis has been left out since it does not convey any relevant information
* Values for east have been rounded to the next integer percentage value since values for west are only exact to whole percentage points too.
* The year for the comparison is assumed to be 1988, the source is given based on assumptions. If this is not clear, it would be better to not use the data at all.

== R-code to generate the graph ==

makepng<-function() {
png("West_ost03.png",bg="transparent",width=700,height=700)
makegraph()
dev.off()
}
makegraph<-function() {
west= c(60,21,10,9)
ost = c(41,16,20,23)
l = c("Schauspiel","Oper/Ballett","Operette/Musical","Sonstige")
m=matrix(c(west,ost),ncol=2)
bs=barplot(m,names=c("West","Ost"),legend.text=l,xlim=c(0,3.5),col=c("blue","green","yellow","red"),cex.names=1.5,axes=FALSE)
text(bs[1],west[1]/2,paste(west[1],"%",sep=""),adj=0.5,cex=2)
text(bs[2],ost[1]/2,paste(ost[1],"%",sep=""),adj=0.5,cex=2)
westcum = cumsum(west)
ostcum = cumsum(ost)
for(i in 2:4) {
text(bs[1],westcum[i-1]+(westcum[i]-westcum[i-1])/2,paste(west[i],"%",sep=""),adj=0.5,cex=2)
text(bs[2],ostcum[i-1]+(ostcum[i]-ostcum[i-1])/2,paste(ost[i],"%",sep=""),adj=0.5,cex=2)
}
title(main = "Besucherverteilung West/Ost 1988", sub="Zahlenspiegel, Bundesministerium für innerdeutsche Beziehungen")
}

== Links ==

* [[Teaching:TUW_-_UE_InfoVis_WS_2007/08|InfoVis:Wiki UE Homepage]]

* [http://ieg.ifs.tuwien.ac.at/~aigner/teaching/infovis_ue/index.html UE InfoVis]

*[[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05|Gruppe 05]]

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 3

2007-12-08T19:06:36Z

UE-InfoVis0708 8007433:

== Poor Graphic ==
[http://ieg.ifs.tuwien.ac.at/~aigner/teaching/infovis_ue/infovis_ue_aufgabe3.html Beschreibung der Aufgabe 3]

[[Image:Besucherverteilung.jpg]]
Besucherverteilung West - Ost

== Review ==

* The essential data values are hidden in the labels that are scattered in small print all over the graph.
* The graphical representation of the data is hard to impossible to grasp: one can suspect that the height of the circular stairs are supposed to be proportional to the percentage. However, there is no reason, why there should be 3D stairs, and even less why those stairs should be circual.
* The pictorial illustration of the different performance types hides the data-related parts of the graph and unnecessary complex as a visual way to distinguish between performance types. In combination with a better graph, and done in a less complex way, such icons could be useful though since they do allow an immediate association of the performace type and are - in comparison to color coding - accessible for color-blind people.
* Overall, data-ink ration on this graph is very low: apart from all the ink-consuming 3D shading, the actual data can really just be gathered from the percentage given in the label texts.
* Organization of the graph into two halves for east/west comparison is good, but to display the data values for each half as rounded stairs makes it extremely difficult to get an impression of the actual distributions.
* Another problem is that the percentage for "Kinder und Jugendthater" is given separately for "West" but is combined with "Schauspiel" for "Ost".
* The values are given sometimes with one digit after the comma for east, but with no digit after the comma for west data.
* It is not clear what the actual source of the data is. The text to the left of the chart hints towards the "Bundesministerium für innerdeutsche Beziehungen" but what has the Promot GmbH got to do with it? What does the "75" in "Quellen" mean and what are the "eigene Berechnungen"?

== Revised diagram ==
[[Image:West_ost03.png]]
== Explanation of changes ==

* The percentage of "Kinder und Jugendtheater" has been combined with "Schauspiel" for "West" too, so that the comparison is made more easy.
* The percentages for "West" and "Ost" are displayed in a standard form for percentages: a stacked bar chart for each of West and Ost (an alternative would have been to use two pie charts, but we believe the data stands out more directly in the stacked bar chart).
* The different categories per chart are coded using color. The color coding was chosen so that red-green blind people (most frequent color blindness) can see the chart easily too.
* The labeling of the categories was done using the text only, the icons were doropped
* Y-axis has been left out since it does not convey any relevant information
* Values for east have been rounded to the next integer percentage value since values for west are only exact to whole percentage points too.
* The year for the comparison is assumed to be 1988, the source is given based on assumptions. If this is not clear, it would be better to not use the data at all.

== R-code to generate the graph ==

<source lang="R">
makepng<-function() {
png("West_ost03.png",bg="transparent",width=700,height=700)
makegraph()
dev.off()
}
makegraph<-function() {
west= c(60,21,10,9)
ost = c(41,16,20,23)
l = c("Schauspiel","Oper/Ballett","Operette/Musical","Sonstige")
m=matrix(c(west,ost),ncol=2)
bs=barplot(m,names=c("West","Ost"),legend.text=l,xlim=c(0,3.5),col=c("blue","green","yellow","red"),cex.names=1.5,axes=FALSE)
text(bs[1],west[1]/2,paste(west[1],"%",sep=""),adj=0.5,cex=2)
text(bs[2],ost[1]/2,paste(ost[1],"%",sep=""),adj=0.5,cex=2)
westcum = cumsum(west)
ostcum = cumsum(ost)
for(i in 2:4) {
text(bs[1],westcum[i-1]+(westcum[i]-westcum[i-1])/2,paste(west[i],"%",sep=""),adj=0.5,cex=2)
text(bs[2],ostcum[i-1]+(ostcum[i]-ostcum[i-1])/2,paste(ost[i],"%",sep=""),adj=0.5,cex=2)
}
title(main = "Besucherverteilung West/Ost 1988", sub="Zahlenspiegel, Bundesministerium für innerdeutsche Beziehungen")
}
</source>

== Links ==

* [[Teaching:TUW_-_UE_InfoVis_WS_2007/08|InfoVis:Wiki UE Homepage]]

* [http://ieg.ifs.tuwien.ac.at/~aigner/teaching/infovis_ue/index.html UE InfoVis]

*[[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05|Gruppe 05]]

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 3

2007-12-08T19:03:54Z

UE-InfoVis0708 8007433:

== Poor Graphic ==
[http://ieg.ifs.tuwien.ac.at/~aigner/teaching/infovis_ue/infovis_ue_aufgabe3.html Beschreibung der Aufgabe 3]

[[Image:Besucherverteilung.jpg]]
Besucherverteilung West - Ost

== Review ==

* The essential data values are hidden in the labels that are scattered in small print all over the graph.
* The graphical representation of the data is hard to impossible to grasp: one can suspect that the height of the circular stairs are supposed to be proportional to the percentage. However, there is no reason, why there should be 3D stairs, and even less why those stairs should be circual.
* The pictorial illustration of the different performance types hides the data-related parts of the graph and unnecessary complex as a visual way to distinguish between performance types. In combination with a better graph, and done in a less complex way, such icons could be useful though since they do allow an immediate association of the performace type and are - in comparison to color coding - accessible for color-blind people.
* Overall, data-ink ration on this graph is very low: apart from all the ink-consuming 3D shading, the actual data can really just be gathered from the percentage given in the label texts.
* Organization of the graph into two halves for east/west comparison is good, but to display the data values for each half as rounded stairs makes it extremely difficult to get an impression of the actual distributions.
* Another problem is that the percentage for "Kinder und Jugendthater" is given separately for "West" but is combined with "Schauspiel" for "Ost".
* The values are given sometimes with one digit after the comma for east, but with no digit after the comma for west data.
* It is not clear what the actual source of the data is. The text to the left of the chart hints towards the "Bundesministerium für innerdeutsche Beziehungen" but what has the Promot GmbH got to do with it? What does the "75" in "Quellen" mean and what are the "eigene Berechnungen"?

== Revised diagram ==
[[Image:West_ost03.png]]
== Explanation of changes ==

* The percentage of "Kinder und Jugendtheater" has been combined with "Schauspiel" for "West" too, so that the comparison is made more easy.
* The percentages for "West" and "Ost" are displayed in a standard form for percentages: a stacked bar chart for each of West and Ost (an alternative would have been to use two pie charts, but we believe the data stands out more directly in the stacked bar chart).
* The different categories per chart are coded using color. The color coding was chosen so that red-green blind people (most frequent color blindness) can see the chart easily too.
* The labeling of the categories was done using the text only, the icons were doropped
* Y-axis has been left out since it does not convey any relevant information
* Values for east have been rounded to the next integer percentage value since values for west are only exact to whole percentage points too.
* The year for the comparison is assumed to be 1988, the source is given based on assumptions. If this is not clear, it would be better to not use the data at all.

== R-code to generate the graph ==

<source lang="R">
makepng<-function() {
png("West_ost03.png",bg="transparent",width=700,height=700)
makegraph()
dev.off()
}
makegraph<-function() {
west= c(60,21,10,9)
ost = c(41,16,20,23)
l = c("Schauspiel","Oper/Ballett","Operette/Musical","Sonstige")
m=matrix(c(west,ost),ncol=2)
bs=barplot(m,names=c("West","Ost"),legend.text=l,xlim=c(0,3.5),col=c("blue","green","yellow","red"),cex.names=1.5,axes=FALSE,
# angle=c(0,45,90,135),density=20
)
text(bs[1],west[1]/2,paste(west[1],"%",sep=""),adj=0.5,cex=2)
text(bs[2],ost[1]/2,paste(ost[1],"%",sep=""),adj=0.5,cex=2)
westcum = cumsum(west)
ostcum = cumsum(ost)
for(i in 2:4) {
text(bs[1],westcum[i-1]+(westcum[i]-westcum[i-1])/2,paste(west[i],"%",sep=""),adj=0.5,cex=2)
text(bs[2],ostcum[i-1]+(ostcum[i]-ostcum[i-1])/2,paste(ost[i],"%",sep=""),adj=0.5,cex=2)
}
title(main = "Besucherverteilung West/Ost 1988", sub="Zahlenspiegel, Bundesministerium für innerdeutsche Beziehungen")
}
</source>

== Links ==

* [[Teaching:TUW_-_UE_InfoVis_WS_2007/08|InfoVis:Wiki UE Homepage]]

* [http://ieg.ifs.tuwien.ac.at/~aigner/teaching/infovis_ue/index.html UE InfoVis]

*[[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05|Gruppe 05]]

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 3

2007-12-08T18:59:07Z

UE-InfoVis0708 8007433:

File:West ost03.png

2007-12-08T18:54:44Z

UE-InfoVis0708 8007433: New page: == Summary == == Copyright status == == Source ==

== Summary ==

== Copyright status ==

== Source ==

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 3

2007-12-08T18:54:17Z

UE-InfoVis0708 8007433:

File:West ost02.png

2007-12-03T19:20:48Z

UE-InfoVis0708 8007433: New page: == Summary == == Copyright status == == Source ==

== Summary ==

== Copyright status ==

== Source ==

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 3

2007-12-03T19:20:22Z

UE-InfoVis0708 8007433:

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 3

2007-12-03T16:48:09Z

UE-InfoVis0708 8007433:

File:West ost.png

2007-12-03T16:44:17Z

UE-InfoVis0708 8007433: Graph for Infovis0708, example 3, group 5

== Summary ==
Graph for Infovis0708, example 3, group 5
== Copyright status ==
Public Domain
== Source ==

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 1 - Generalization

2007-11-09T19:00:10Z

UE-InfoVis0708 8007433: Made first sentence more concise, moved main area to Overview, added example.

= Generalization =
Generalization is the abstraction away from aspects of the reality which are not important for some analysis or question at hand.
==Definition==
A. Hettner defines Generalization as 
„… a selection of the most important, the essence and the target-oriented simplification. In this process, it is important that the map shows the most important, characteristically attributes, which are needed for the use, the topic and the scale of the map.“

== Overview ==
An important area of generalization techniques is the field of visualizing geographical information and geo-spacial data in 2D maps. Here, in order to make a specific kind of information easily graspable, it is necessary to suppress unnecessary information. An example might be routes in a navigation system: to make it easy to recognize and understand the route, it is important to include necessary information, e.g. roads or landmarks along the route, but suppress unnecessary detail like roads or geographical entities away from the route that are not important for locating points on or following along the route (Agrawala2001).

It depends on the scale, which information can be shown on a map. The designer of a printed map can decide, which information is shown (i.e. toponyomies, name of the streets, rivers…) and on which position within the map this information should be placed. But digital maps aren´t produced in traditional way. Users can zoom within these maps. It depends on the zoom-factor, which information is shown. The computer has to decide, which information is shown on which position. For this procedure algorithms are needed.

== Goals of generalization ==
# Improve the message of the map
# Improve the communication of the content of the map
# Improve the speed of the collection of data
# Help to find answers on questions
# The shown information should be useful for the target-audience (i.e. maps for traffic-engineers, city-engineers, environment-engineers…)

== When should be generalized? ==
# If a map has too much information. Then it´s hard to understand the information (i.e. different symbols, Overlapping of symbols, colors…)
# If a map is designed only for a special audience and only a special conclusion is needed
# If information could be combined
# If maps lose their character because there are too much of information
# If important information is unnoticed
# If objects are too small, if they are shown in „correct“ scale

== Kinds of generalization? ==
# Simplifications (i.e. defines of shapes)
# Straighten (i.e. curve)
# Aggregation (i.e. arrangement of objects)
# Combination (z. B. important information overlap less important information)
# Union (i.e. many objects are combined to one)
# Change the symbols (i.e. from shape-symbols to point-symbols)

== Examples ==
[[Image:Gr05_uebung1_generalization_01.png]]

All 3 figures show the same segment of the map 
Figure 1 shows the most details. The shapes of the buildings are not simplified yet. This map doesn´t show the main-street. 
Figure 2 shows with the color yellow the main-street. The shapes of the building are simplified (only rectangles are shown). The quantity of the buildings is not equal with the “real” quantity. 
Figure 3 doesn´t show details like some streets or the little river on the bottom-left side. The building in the middle is now presented with a flag. This visualization doesn´t represent the reality, but it increases the important of the building 
Figure 4 shows more examples of generalization 

[[Image:Gr05_uebung1_generalization_02.png]]

==References==
[Agrawala, 2001] Maneesh Agrawala and Chris Stolte, Rendering Effective Route Maps: Improving Usability Through Generalization. SIGGRAPH 2001, Computer Graphics Proceedings. ACM Press / ACM SIGGRAPH.

[Sester, 2001] Monika Sester, Maßstabdsabhängige Darstellung in digitalen räumlichen Datenbeständen, Universität Stuttgart, http://www.ikg.uni-hannover.de/publikationen/publikationen/2001/sester_habil.pdf

[swisstopo, 2001] Schweizer Gesellschaft für Kartographie, Topografische Karten Kartengrafik und Generalisierung, http://www.swisstopo.ch/pub/down/basics/karto/demoNo16_de.pdf

[Möltgen, 2003] Jörn Möltgen, Generalisierung, Universität Münster, http://ifgi.uni-muenster.de/~moltgej/Lehre/Karto_SS2003/7.Generalisierung.pdf

All pictures are taken from this publications

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 1 - Rendering

2007-11-09T18:40:07Z

UE-InfoVis0708 8007433:

= Rendering =
==Definition==
Rendering is the process of creating a viewable image from a model or mathematical representation.
== Overview ==
Rendering as a technical term means the algorithmic creation of an image from a mathematical representation of objects, scenes, or data.
In computer graphics, the task is most often to render a realistic 2D image of a 3D scene where the objects of the scene are represented by geometrical primitives like vertices, surfaces, vectors, splines, etc. and where the rendering is parametrized by information about light sources, camera position or camera focal distance etc. In 3D computer animation, the task is to create a sequence of images where the content of the scene or the camera parameters change from image to image.

In the context of information visualization, the mathematical representation can be more abstract: it could be data from a GIS (geographical information system) where the result image could be a 2D map representation of a geographical area or a 3D bird-view of the area.
It could also be a set of vectors (multivariate data) where the rendering creates an easily graspable 2D image of the multimensional
data, for example with a parallel coordinate display (Johansson et. al. 2005).

In the area of computer graphics, an important research topic is the effective and fast as well as realistic creation of the 2D image from the mathematical model. This is hard because the for a realistic rendering, the scene has to be described by a massive amount of data and the creation of a realistic representation that includes shadows, texture, mirror images, transparent objects requires a massive amount of computation.

In the area of information visualization, performance issues are important when the amount of data to visualize becomes large, but since the real aim is to create an image that should be easily graspable the research questions are more related to issues of ''in what way'' to render the data, how to interact with the rendered image, or how to emphasize what is important and suppress unimportant detail (see [[Teaching:TUW_-_UE_InfoVis_WS_2007/08_-_Gruppe_05_-_Aufgabe_1_-_Generalization|Generalization]])

== Techniques ==
There are several different techniques:
# '''wire frame:''' This is the abstract representation of the object just with edges (with or without visible surface detection)
# '''scan fill:''' This rendering mode just fills the object with a solid color and doesn't consider any lighting, shading or reflections
# '''flat shading:''' -considers different lighting aspects (shading) and reflections. Every polygon mesh is filled with the same color, but it varies within the object. This method takes care of all lighting aspects, but it doesn't give you a smooth surface, because you still see all the edges from the wire frame.
# '''gouraud shading, phong shading:''' These are two similar techniques to create very smooth surfaces. The computation of the surface is complex, therefore it needs more computing power than the previous techniques, but today this kind of rendering is no problem at all, because nearly every computer has enough computation power to do this kind of rendering (of course, it depends on the scene, you're trying to render).

<gallery caption="" widths="100px" heights="100px" perrow="6">
Image:Wire frame.jpg|teapot represented by wire frames; no visible-surface detection
Image:Wire_frame_backface_culling.jpg|teapot represented by wire frames with visible-surface detection
Image:Scan_filled.jpg|teapot with scan-fill rendering
image:Flat_shaded.jpg|teapot with flat shaded rendering
image:Gouraud_shaded.jpg|teapot with gouraud shaded rendering
image:Phong_shaded.jpg|teapot with phong shaded rendering
</gallery>

==Visible surface detection==
This is not a special rendering technique, but it's the basics for the rendering. The object is represented through different edges (wire frame) which describes the object surface. There are mainly two different ways to represent the object in wire frames:
# you can see all edges, even if you shouldn't see them, because they are in the background of the object (hidden by the front surface)
# you do some kind of visible-surface detection; therefore you need algorithms to decide which edges should be visible and which shouldn't. You have to identify the visible parts of a scene.
==References==
Jimmy Johansson, Patric Ljung, Mikael Jern, and Matthrew Cooper. Revealing Structure within Clustered Parallel Coordinates Displays.
IEEE International Conference on Information Visualization (InfoVis 2005), IEEE Computer Society Press, 2005.

[Purgathofer, 2005] Werner Purgathofer, Computer Graphics 1 (lecture). Date of lecture: 2005. http://www.cg.tuwien.ac.at/courses/CG/slides.html

[Unknown, ?] Unknown, Rendering: Definition. Created at: ?. Retrieved at: November 3, 2007. http://www.itwissen.info/definition/lexikon//__rendering_rendering.html

All pictures are created on my own with the CG1 LU Framework which was used in the lecture "CG1 LU" in 2005.

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 1 - Rendering

2007-11-09T18:38:12Z

UE-InfoVis0708 8007433: Changes to definition and Overview (forgot to log in, IP 62.178.89.44)

= Rendering =
==Definition==
Rendering is the process of creating a viewable image from a model or mathematical representation.
== Overview ==
Rendering as a technical term means the algorithmic creation of an image from a mathematical representation of objects, scenes, or data.
In computer graphics, the task is most often to render a realistic 2D image of a 3D scene where the objects of the scene are represented by geometrical primitives like vertices, surfaces, vectors, splines, etc. and where the rendering is parametrized by information about light sources, camera position or camera focal distance etc. In 3D computer animation, the task is to create a sequence of images where the content of the scene or the camera parameters change from image to image.

In the context of information visualization, the mathematical representation can be more abstract: it could be data from a GIS (geographical information system) where the result image could be a 2D map representation of a geographical area or a 3D bird-view of the area.
It could also be a set of vectors (multivariate data) where the rendering creates an easily graspable 2D image of the multimensional
data, for example with a parallel coordinate display (Johansson et. al. 2005).

In the area of computer graphics, an important research topic is the effective and fast as well as realistic creation of the 2D image from the mathematical model. This is hard because the for a realistic rendering, the scene has to be described by a massive amount of data and the creation of a realistic representation that includes shadows, texture, mirror images, transparent objects requires a massive amount of computation.

In the area of information visualization, performance issues are important when the amount of data to visualize becomes large, but since the real aim is to create an image that should be easily graspable the research questions are more related to issues of ''in what way'' to render the data, how to interact with the rendered image, or how to emphasize what is important and suppress unimportant detail (see [[Generalization]])

== Techniques ==
There are several different techniques:
# '''wire frame:''' This is the abstract representation of the object just with edges (with or without visible surface detection)
# '''scan fill:''' This rendering mode just fills the object with a solid color and doesn't consider any lighting, shading or reflections
# '''flat shading:''' -considers different lighting aspects (shading) and reflections. Every polygon mesh is filled with the same color, but it varies within the object. This method takes care of all lighting aspects, but it doesn't give you a smooth surface, because you still see all the edges from the wire frame.
# '''gouraud shading, phong shading:''' These are two similar techniques to create very smooth surfaces. The computation of the surface is complex, therefore it needs more computing power than the previous techniques, but today this kind of rendering is no problem at all, because nearly every computer has enough computation power to do this kind of rendering (of course, it depends on the scene, you're trying to render).

<gallery caption="" widths="100px" heights="100px" perrow="6">
Image:Wire frame.jpg|teapot represented by wire frames; no visible-surface detection
Image:Wire_frame_backface_culling.jpg|teapot represented by wire frames with visible-surface detection
Image:Scan_filled.jpg|teapot with scan-fill rendering
image:Flat_shaded.jpg|teapot with flat shaded rendering
image:Gouraud_shaded.jpg|teapot with gouraud shaded rendering
image:Phong_shaded.jpg|teapot with phong shaded rendering
</gallery>

==Visible surface detection==
This is not a special rendering technique, but it's the basics for the rendering. The object is represented through different edges (wire frame) which describes the object surface. There are mainly two different ways to represent the object in wire frames:
# you can see all edges, even if you shouldn't see them, because they are in the background of the object (hidden by the front surface)
# you do some kind of visible-surface detection; therefore you need algorithms to decide which edges should be visible and which shouldn't. You have to identify the visible parts of a scene.
==References==
Jimmy Johansson, Patric Ljung, Mikael Jern, and Matthrew Cooper. Revealing Structure within Clustered Parallel Coordinates Displays.
IEEE International Conference on Information Visualization (InfoVis 2005), IEEE Computer Society Press, 2005.

[Purgathofer, 2005] Werner Purgathofer, Computer Graphics 1 (lecture). Date of lecture: 2005. http://www.cg.tuwien.ac.at/courses/CG/slides.html

[Unknown, ?] Unknown, Rendering: Definition. Created at: ?. Retrieved at: November 3, 2007. http://www.itwissen.info/definition/lexikon//__rendering_rendering.html

All pictures are created on my own with the CG1 LU Framework which was used in the lecture "CG1 LU" in 2005.

Teaching talk:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 0

2007-11-04T21:39:48Z

UE-InfoVis0708 8007433:

'''Begründung:'''

Johann Petrak: Bitte IRGENDEIN Bild in die Userpage einbauen. Studienkennzahl fehlt noch.
: gemacht [[User:UE-InfoVis0708 8007433|UE-InfoVis0708 8007433]] 22:39, 4 November 2007 (CET)

Das Foto von Andreas Sackl ist noch nicht in die Userpage eingebaut.

User:UE-InfoVis0708 8007433

2007-11-04T21:34:55Z

UE-InfoVis0708 8007433: Fehlendes Bild und Stud-Kz hinzugefügt

* Johann Petrak
* Das Bild: [[Image:I2007-05-0-jp.jpg]]
* Matrikelnummer: 8007433
* Studienkennzahl: E 086 881
* johann (adothere) petrak (theatgoeshere) chello (onedot) at

Gruppe: [[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05]] 
UE-Home: [[Teaching:TUW_-_UE_InfoVis_WS_2007/08]]

File:I2007-05-0-jp.jpg

2007-11-04T21:30:33Z

UE-InfoVis0708 8007433: required image for exercise 0

== Summary ==
required image for exercise 0
== Copyright status ==
public domain
== Source ==

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 2

2007-10-23T22:12:49Z

UE-InfoVis0708 8007433: New page: stub so far

stub so far

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 0

2007-10-23T22:11:29Z

UE-InfoVis0708 8007433: New page: Alle Seiten und User angelegt.

Alle Seiten und User angelegt.

Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05 - Aufgabe 1

2007-10-23T22:09:46Z

UE-InfoVis0708 8007433: New page: stub so far

stub so far

Teaching:TUW - UE InfoVis WS 2007/08

2007-10-23T11:57:42Z

UE-InfoVis0708 8007433:

[[Image:Aigner03infovis ue.gif]] <big>WS 2007/08</big>

'''LVA Nr:''' 188.308 ([http://tuwis.tuwien.ac.at/lva/tuwien/188308 TUWIS++ Seite])

'''LVA Homepage:''' http://ieg.ifs.tuwien.ac.at/~aigner/teaching/infovis_ue/index.html

'''Leitung:''' [[Aigner, Wolfgang|Wolfgang Aigner]] [aigner (at) ifs.tuwien.ac.at] 
'''Tutor:''' [[User:ASchratt|Alexander Schratt]] [alexander.schratt (at) donau-uni.ac.at]

== Gruppen ==

[[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 01|Gruppe 01 (Kaburek)]] 
[[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 02|Gruppe 02 (KOGLER)]] 
[[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 03|Gruppe 03 (DELPORTE)]] 
[[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05|Gruppe 05 (Petrak, Planinc, Sackl)]] 

== News / Bemerkungen ==

User:UE-InfoVis0708 8007433

2007-10-22T19:35:30Z

UE-InfoVis0708 8007433:

* Johann Petrak
* Ich bin nicht einverstanden hier ein Foto zu veröffentlichen, tut mir leid.
* Matrikelnummer: 8007433
* johann (adothere) petrak (theatgoeshere) chello (onedot) at

Gruppe: [[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05]] 
UE-Home: [[Teaching:TUW_-_UE_InfoVis_WS_2007/08]]

User:UE-InfoVis0708 8007433

2007-10-21T21:56:16Z

UE-InfoVis0708 8007433:

* Johann Petrak
* Ich bin nicht einverstanden hier ein Foto zu veröffentlichen, tut mir leid.
* Matrikelnummer: 8007433
* johann.petrak (at) chello.at

Gruppe: [[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05]] 
UE-Home: [[Teaching:TUW_-_UE_InfoVis_WS_2007/08]]

User:UE-InfoVis0708 8007433

2007-10-21T21:55:55Z

UE-InfoVis0708 8007433:

Teaching:TUW - UE InfoVis WS 2007/08

2007-10-21T21:53:16Z

UE-InfoVis0708 8007433:

[[Image:Aigner03infovis ue.gif]] <big>WS 2007/08</big>

'''LVA Nr:''' 188.308 ([http://tuwis.tuwien.ac.at/lva/tuwien/188308 TUWIS++ Seite])

'''LVA Homepage:''' http://ieg.ifs.tuwien.ac.at/~aigner/teaching/infovis_ue/index.html

'''Leitung:''' [[Aigner, Wolfgang|Wolfgang Aigner]] [aigner (at) ifs.tuwien.ac.at] 
'''Tutor:''' [[User:ASchratt|Alexander Schratt]] [alexander.schratt (at) donau-uni.ac.at]

== Gruppen ==

[[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 01|Gruppe 01 (Kaburek)]] 
[[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 03|Gruppe 03 (DELPORTE)]] 
[[Teaching:TUW - UE InfoVis WS 2007/08 - Gruppe 05|Gruppe 05 (Petrak)]] 

== News / Bemerkungen ==

User:UE-InfoVis0708 8007433

2007-10-21T21:51:02Z

UE-InfoVis0708 8007433: