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Ripple AddObject Method

Ripple allows the creation of ripple tank sources as well as geometric shapes such as circles and rectangles using the addObject method.

addObject(String name, String attributes)

Objects usually, but not always, have an on-screen representation.  The first argument is the name of the object to be added, and the second is a comma-delimited list of parameters.  A circle can now be added to either applet using the following JavaScript statement:

document.physletname.addObject("circle", "x=0,y=-1.0,r=10");.

The addObject method is very forgiving since not all parameters need to be specified.  Default values are overridden only if the parameter appears in the list.  Incorrect and unsupported parameters do not affect the applet and are ignored.

The table below lists the name and the associated parameters for version 4 of the Ripple Physlet.   Consult the online documentation for information about other Physlets.  OpticsBench, for example, supports the addObject method for lenses, mirrors, and light sources.

Name  Attributes
arrow

Arrows are often animation slaves of other objects.  They can represent almost any vector since the h and v components can be functions of the variables.

x- double position of the base in world units
y- double position of the base in world units.
h- string horizontal component
v- string vertical component
s -int size of arrowhead
box

A hollow rectangle.

 

x- double position of the base in world units
y- double position of the base in world units.
h- int height in pixels
w- int width in pixels
caption

Text.

x- double position of the base in world units
y- double position of the base in world units.
txt- string text
constraint

A constraint on dragged objects.

 

xmin- double minimum x
xmax- double maximum x
ymin- double minimum y
ymax- double maximum y
circle

A filled circle.

x- double position of the base in world units
y- double position of the base in world units.
r- int radius in pixels
label- string a text label
cursor

A circle with crosshairs

x- double position of the base in world units
y- double position of the base in world units.
r- int radius in pixels
image

A gif image.

x- double position of the base in world units
y- double position of the base in world units.
file- string image file relative to code base
protractor
a protractor for measuring angles

x- double x position of the vertex in world units
y- double y position of the vertex in world units.
s- int base size in pixel
theta- double vertex interior angle
theta0- double vertex base angle
fixedbase- fixes the base angle
fixedsize- fixes the length of the arm
rectangle

A filled rectangle.

x- double position of the base in world units
y- double position of the base in world units.
h- int height in pixels
w- int width in pixels
label- string a text label
shell

A hollow circle.

x- double position of the base in world units
y- double position of the base in world units.
r- int radius in pixels
source

A wave source.

x- double position of the base in world units
y- double position of the base in world units.
amp- double amplitude
phase- double phase
label- string a text label
text

A text message with an optional calculation.

x- double position of the base in world units
y- double position of the base in world units.
txt- string message