- Quickstart
- What is it?
- Installation
- Examples
- Behavior
- Primitives
- Building
- Authors
- Feedback
- Credits
- Terms of use
Include the extension in your NetLogo model (at the top):
extensions [structs]
Stacks
Create a global varaible to store the stack and add some data to the stack in the setup procedure:
globals[stack]
to setup
set stack structs:new-stack
stackucts:stack-push stack 1
stackucts:stack-push stack 2
stackucts:stack-push stack "hello world"
stackucts:stack-push stack [5 6 7]
end
Report the size of the stack on the command line:
show structs:stack-count stack
Does your stack contain 2?
show structs:stack-contains stack 2
Pop the data from the stack, assigning the returned values to variables (note last in, first out):
to pop
let a structs:stack-pop str
let b structs:stack-pop str
let c structs:stack-pop str
let d structs:stack-pop str
print a
print b
print c
print d
end
This package contains the NetLogo structs extension, which provides NetLogo with a variety of common java data structures that are useful programming tools.
Stacks
A stack is like a list but the manner in which elements are added and removed from the list is unique. To add elements, you "push" them onto the stack. At any time you can then "pop" the elements from the stack which simultaneously returns the last element to be pushed and removes that element from the stack. Like a stack of dishes, you push new elements onto the top of the stack and you pop elements off the top, so last in is first out.
First, download the latest version of the extension. Note that the latest version of this extension was compiled against NetLogo 5.0.4; if you are using a different version of NetLogo you might consider building your own jar file (see building section below).
Unzip the archive and move the directory to the "extensions" directory inside your NetLogo application folder (i.e. [NETLOGO]/extensions/). Or you can place the directory under the same directory holding the NetLogo model in which you want to use this extension.
For more information on NetLogo extensions: http://ccl.northwestern.edu/netlogo/docs/extensions.html
See the example models in the extension subfolder "examples" for thorough demonstrations of usage.
The structs extension introduces some new data types (more detail about these is provided in the behavior section):
- LogoStack - A LogoStack object stores a stack.
Elements of logostacks can be any valid Netlogo object. Like a list, stacks can contain a mixture of data types.
structs:new-stack
structs:new-stack
Reports a logostack.
let stack structs:new-stack
structs:stack-push
structs:stack-push logostack element
Pushes element onto the logostack.
structs:stack-push stack 99
structs:stack-pop
structs:stack-pop logostack
Reports the latest element to be pushed onto logostack and removes that element from the stack.
structs:stack-push stack 99
structs:stack-push stack 100
print structs:stack-pop stack
print structs:stack-pop stack
;; this will print "100" and then "99"
structs:stack-peek
structs:stack-peek logostack
Reports the latest element to be pushed onto logostack but does not remove that element from the stack.
structs:stack-push stack 99
structs:stack-push stack 100
print structs:stack-peek stack
print structs:stack-peek stack
;; this will print "100" and then "100"
structs:stack-count
structs:stack-count logostack
Reports the number of elements in the logostack.
structs:stack-contains
structs:stack-contains logostack element
Tests if element is contained in logostack, returning true or false.
Use the NETLOGO environment variable to tell the Makefile which NetLogoLite.jar to compile against. For example:
NETLOGO=/Applications/NetLogo\\\ 5.0 make
If compilation succeeds, structs.jar will be created. See Installation for instructions on where to put your compiled extension.
Colin Sheppard
Please visit the github issue tracker to submit comments, bug reports, or feature requests. I'm also more than willing to accept pull requests.
The NetLogo structs extension is under GPL v3.