3DSCAT.pdf

8/12/2019 3DSCAT.pdf

1/10

1041

CHAPTER 45

3D Scatter PlotsIntroduction

General Purpose and DescriptionThe 3D scatter plot displays trivariate points plotted in an X-Y-Z grid. It is particularly useful for

investigating the relationships among these variables. The influence of a discrete variable may be

investigated by using a different plotting symbol for each value of this variable. Hence, up to four

variables (three numeric and one discrete) may be displayed on a single graph.

This procedure has the ability to rotate the data, giving the allusion of motion. This allows the

human brain to better interpret the data.

Scatter Chart

1

2

3SepalWidth

Iris

SepalLength PetalLength

0

20

40

6080

10

20

30

40

50

4050

60

70

80

Data Structure

The data are entered in three numeric variables. A fourth, discrete variable may be used to definethe plotting symbol and color. Below are shown the first few rows of the 150-observation Fisher

Iris dataset. These data are contained in the FISHER database.


2/10

1042 3D Scatter Plots

Table 98.1 - Part of Fishers Iris Data

Iris SepalLen SepalWid PetalLen

1 50 33 14

3 64 28 56

2 65 28 46

3 67 31 56

3 63 28 511 46 34 14

3 69 31 51

2 62 22 45

Procedure OptionsThis section describes the options available in this procedure. To find out more about using a

procedure, turn to the Procedures chapter.

Variables Tab

Specify the variables used to make the scatter plot.

Y (Vertical) VariableSpecify the variable displayed along the Y (vertical) axis. Only numeric values are used.

X1 VariableSpecify the variable displayed across the X1 (horizontal - left) axis. Only numeric values are used.

X2 VariableSpecify the variable displayed across the X2 (depth or horizontal - right) axis. Only numeric values

are used.

Symbol VariableSpecify an optional discrete variable whose values are used to defined the plotting color and

symbol. If this variable is omitted, the first symbol and color are used.

Edit Chart InteractivelyChecking this option will cause the interactive graphics editor to be displayed. This allows you to

modify the graph interactively at run time. This editor is documented in its help file. Once you are

through editing the plot, it will be displayed permanently in the output document.

Once the graphics editor comes up, you can use the scroll-bars on the four sides of the graph to

interactively rotate the plot to the viewing position and angle that you like the best.


3/10

Chapter 45 3D Scatter Plots 1043

Show SticksThis option controls the display of the vertical lines between the points and the plot floor.

No Yes

Scatter Chart

1

2

3SepalWidth

Iris


0

20

40

6080

10

20

30

40

50

4050

60

70

80

Scatter Chart

1

2

3SepalWidth

Iris


0

20

40

6080

10

20

30

40

50

4050

60

70

80

Filter Active

This option indicates whether the currently defined filter (if any) should be used when running this

procedure.

Titles TabThese options control the titles that may be placed on all four sides of the chart. Note that the

symbols {Y}, {X1}, and {X2} are replaced by the corresponding variable names.

Top Title

This option gives the text that will appear in the title at the top of the chart. The color, font size, and

style of the text is controlled by the options to the right.

Bottom Title

This option gives the text that will appear in the title at the bottom of the chart. The color, font size,

and style of the text is controlled by the options to the right.

Left Title

This option gives the text that will appear in the title at the left of the chart. This may also serve as a

label. The color and orientation of the text is controlled by the options to the right.

Right Title

This option gives the text that will appear in the title at the right of the chart. This may also serve as

a label. The color and orientation of the text is controlled by the options to the right.

Variable Names

This option lets you select whether to display only variable names, variable labels, or both.

References TabThis panel controls the color and size of the reference labels.

Text Color

This option sets the color of the reference items along the two axes.

Font Size

This option sets the font size of the reference items along the two axes.


4/10


Text Rotation

This option sets the display angle of the reference items along the horizontal axis.

Bold and Italics

This option sets the style of the reference items along the two axes.

Axes TabThese options control the appearance and position of the axes.

Y, X1, X2 Scaling

This option specifies whether the axis is scaled automatically, with a zero axis origin, or from user

specified maximum, minimum, and number of tick marks.

Y, X1, X2 Maximum

Sets the value of the axis maximum. This value must be greater than the largest data value. This

value is only used when Scaling is set to User Defined.

Y, X1, X2 Minimum

Sets the value of the axis minimum. This value must be smaller than the smallest data value alongthis axis. This value is only used when Scaling is set to User Defined.

Y, X1, X2 Ticks

Sets the number of tickmarks. This value is only used when Scaling is set to User Defined.

Grid Line Style

Specify the style (line, dots, dashes, etc.) of the grid lines.

Cage Flip

This option controls whether the back and side walls of the graph cage are allowed to switch to the

opposite edge for better viewing.

Thin WallsThis option specifies whether the walls of the axis grid that forms the background of the chart are

thick or thin.

Grid Color

Set the color of the grid lines.

Cage Wall Color

Set the color of the cage wall in 3D charts.

Cage Edge Color

Set the color of the cage edge in 3D charts.

Show Vertical GridSpecify whether to display the vertical grid lines.

Show Horizontal Grid

Specify whether to display the horizontal grid lines.


5/10


3D Options TabThese options control the viewing orientation of the plot. These options may be set interactively by

checking the Edit Chart Interactively option and then activating the four scroll bars on the sides of

the Graphics Editor window.

PerspectiveThis option specifies the perceived distance from which the graph is viewed. The range is from 0 to100. As the value gets large, the distance gets smaller. A setting of 50 sets the viewing distance at

about twice the graphs width. A setting of 100 sets the viewing distance at about equal to the

graphs width.

Perspective = 10 Perspective = 90

Scatter Chart

1

2

3S

epalWidth

Iris


0

20

40

6080

10

20

30

40

50

4050

60

70

80

Scatter Chart

1

2

3S

epalWidth

Iris


0

20

40

6080

10

20

30

40

50

4050

60

70

80

ElevationThis option sets the vertical viewing angle (in degrees). The setting represents an angle above or

below a point halfway up the graph. The range is from -60 to 90.

Elevation = -20 Elevation = 50

Scatter Chart

1

2

3SepalWidth

Iris


10

20

30

40

50

020

40 60 80405060

7080

Scatter Chart

1

2

3SepalWidth

Iris


0

20

40

60

80

1020

30

40

50

40

50

60

70

80


6/10


RotationThis option sets the horizontal viewing angle (in degrees). The setting represents an angle around

the base of the graph. The range is from -180 to 180.

Rotation = -45 Rotation = 45

Scatter Chart

1

2

3SepalWidth

Iris


0

20

40

6080

10

20

30

40

50

40

50

60

7080

Scatter Chart

1

2

3SepalWidth

Iris


0

20

40

60

80

10

20

30

40

50

40

50

60

70

80

DepthThis option sets the width in the X2 direction. The range is from 1 to 20,000.

Depth = 20 Depth = 400

Scatter Chart

1

2

3SepalWidth

Iris


0 20

4060

80

10

20

30

40

50

40

50

60

70

80

Scatter Chart

1

2

3SepalWidth

Iris


0

20

40

6080

10

20

30

40

50

4050

60

70

80

Projection MethodThis option specifies the method used to determine viewer position and angle in a 3D graph.

Isometric Perspective

Scatter Chart

1

2

3SepalW

idth

Iris


0

20

40

60

80

10

20

30

40

50

40

50

60

70

80

Scatter Chart

1

2

3SepalW

idth

Iris


0

20

40

6080

10

20

30

40

50

40

50

60

70

80


7/10


Legend TabThese options specify the legend. Note that the legend is only displayed when a Symbol Variable is

selected.

Position

This option sets the position of the legend around the chart. Note that if you choose a position inwhich the full text of the legend cannot be fit, the legend will not be displayed.

Percent Vertical

Specify the size of the legend as a percentage of the maximum possible. This option lets you shrink

a legend that is too large.

Text Color

Specify the color of the legend text.

Background

Specify the background color of the legend.

Font SizeSpecify the size of the legend text.

Bold and Italics

Specify the style of the legend text.

Back Style

Specify the background style of the legend.

Color as Labels

Normally, text in the legend is displayed using the color selected by the Text Color option. This

option indicates that each legend entry is to be displayed in the corresponding group color.

Background TabThese options specify the colors and background styles of various sections of the plot.

Entire Graph

Specify the background color and style of the entire plot.

Inside Graph

Specify the background color and style of the plot itself (within the axes).

Graph Title

Specify the background color and style of the plot title.

Left Title

Specify the background color and style of the left title.

Right Title

Specify the background color and style of the right title.

Bottom Title

Specify the background color and style of the bottom title.


8/10


Symbols 1 and 2 TabsThese options specify the colors and patterns used for the plotting symbols. A different plotting

symbol is displayed for each unique value of the Symbol Variable. If no Symbol Variable is

specified, the settings of Symbol 1 are used for the plot symbol.

Symbol 1 - 15These options let you specify the color and type of each symbol. The first symbol is associated withthe first value, the second symbol with the second value, and so on. If more than fifteen symbols

are needed, they are reused so that symbol 16 = symbol 1, symbol 17 = symbol 2, and so on.

Template TabThe options on this panel allow various sets of options to be loaded (File menu: Load Template) or

stored (File menu: Save Template). A template file contains all the settings for this procedure.

File Name

Designate the name of the template file either to be loaded or stored.

Template Files

A list of previously stored template files for this procedure.

Template Ids

A list of the Template Ids of the corresponding files. This id value is loaded in the box at the

bottom of the panel.

TutorialThis section presents an example of how to create a 3D scatter plot of the data stored on the

FISHER database.

1 Open the Fisher dataset.

From the File menu of the NCSS Data window, select Open.

Select the Datasubdirectory of the NCSS97directory.

Click on the file Fisher.s0.

Click Open.

2 Open the 3D Scatter Plot window.

On the menus, select Graphics, then Charts, then 3D Scatter Plot. The 3D Scatter Plot

procedure will be displayed.

On the menus, select File, then New Template. This will fill the procedure with the default

template.

3 Specify the variables.

On the 3D Scatter Plot window, select the Variables tab.

Double-click in the Y (Vertical) Variable text box. This will bring up the variable selection

window.

Select SepalWidthfrom the list of variables and then click Ok. SepalWidth will appear

in the Y Variable box.

Double-click in the X1 Variable text box. This will bring up the variable selection window.

Select SepalLengthfrom the list of variables and then click Ok. SepalLength will appear

in the X1 Variable box.


9/10



Select PetalLengthfrom the list of variables and then click Ok. PetalLength will appear


Double-click in the Symbol Variable text box. This will bring up the variable selection

window.

Select Irisfrom the list of variables and then click Ok. Iris will appear in the SymbolVariable box.

4 Run the procedure.

From the Run menu, select Run Procedure. Alternatively, just click the Run button (the

left-most button on the button bar at the top).

Figure 45.1 3D Scatter Plot

Scatter Plot

1

2

3

SepalWidth

Iris


0

20

40

60

80

10

20

30

40

50

40

50

60

70

80

Tutorial - Interactive RotationThis section presents an example of real-time rotation of a 3D scatter plot of the data stored on the

FISHER database.

1 Open the Fisher dataset.

From the File menu of the NCSS Data window, select Open.

Select the Datasubdirectory of the NCSS97directory.

Click on the file Fisher.s0.

Click Open.

2 Open the 3D Scatter Plot window.

On the menus, select Graphics, then Charts, then 3D Scatter Plot. The 3D Scatter Plot

procedure will be displayed.

On the menus, select File, then New Template. This will fill the procedure with the default


10/10


template.

3 Specify the variables.

On the 3D Scatter Plot window, select the Variables tab.

Double-click in the Y (Vertical) Variable text box. This will bring up the variable selection

window.

Select SepalWidthfrom the list of variables and then click Ok. SepalWidth will appearin the Y Variable box.


Select SepalLengthfrom the list of variables and then click Ok. SepalLength will appear



Select PetalLengthfrom the list of variables and then click Ok. PetalLength will appear


Double-click in the Symbol Variable text box. This will bring up the variable selection

window.

Select Irisfrom the list of variables and then click Ok. Iris will appear in the SymbolVariable box.

Check the Edit Chart Interactivelybox.

4 Specify the axes.

On the 3D Scatter Plot window, select the Axes tab.

Check the Thin Wallsoption.

Click the Show Vertical Gridoption so that it is not checked.

Click the Show Horizontal Gridoption so that it is not checked.

Set the Cage Wall Colorto white by clicking the button and checking the white color

button on the Color of Cage Wall Color window.

5 Run the procedure. From the Run menu, select Run Procedure. Alternatively, just click the Run button (the

left-most button on the button bar at the top). This will cause the 3D Scatter Plot Editing

window to appear.

The scroll bar on the left controls the vertical view angle. Try moving the thumb of this

scroll bar up and down. The scatter plot will have the appearance of motion.

The scroll bar on the bottom controls the horizontal view angle. Try moving the thumb of

this scroll bar right and left. The scatter plot will have the appearance of motion.

The other two scroll bars control the depth and perspective of the plot.

The tool bar at the top allows the setting of almost every detail of the plot.

3DSCAT.pdf

Documents

Transcript of 3DSCAT.pdf