Booktrade
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breed [readers reader] breed [booksellers bookseller] breed [manuscripts manuscript] readers-own [ book-list number-of-books money curiosity my-seller ] booksellers-own [ my-manuscripts min-title-diversity preferred-print-run price-target career-span capital ] manuscripts-own [ my-publisher title editions appeal price depreciation-rate book-age-threshold earnings expenses copies-on-the-shelf shelf-time viable failed-solicitations ] to setup ca ; Booksellers publish and distribute manuscripts. They have a capital of money, and if they slip ; into too much debt, they go bankrupt and die. set-default-shape booksellers "house" create-booksellers initial-booksellers [ set color brown set size 3 set career-span 0 set min-title-diversity 0 set preferred-print-run 200 - random 190 set price-target 0.5 + random-gamma 1 2 set my-manuscripts nobody set capital initial-capital setxy random-xcor random-ycor ] ; Readers' behavior is controlled by several variables: color, closed-mindedness, and money. All readers will ; seek out books of their own color. If they are curious (that is, not incurious) they will also ; look for books of different color. They gain money every tick and use money to buy books. set-default-shape readers "circle" create-readers number-of-readers [ set color 55 + random-float 4 set money 0.5 + random-gamma 1 2 set book-list [] set size 1.5 set curiosity random 100 set my-seller one-of booksellers setxy random-xcor random-ycor ] ; Manuscripts are owned by booksellers. They are "published" by hatching ; a number of books that share their variables. set-default-shape manuscripts "star" reset-ticks end ; Go activates readers and booksellers. to go tick ask readers [ determine-behavior ] ask booksellers [manage-inventory check-accounts] if not any? booksellers [ stop ] if mean [capital] of booksellers > initial-capital * 2 or mean [career-span] of booksellers > 500 [ create-booksellers 1 [ set color brown set size 3 set career-span 0 set preferred-print-run 200 - random 190 set price-target 0.5 + random-gamma 1 2 set my-manuscripts nobody set capital initial-capital setxy random-xcor random-ycor ] ] end to determine-behavior set curiosity curiosity + 1 if my-seller = nobody [ set my-seller one-of booksellers ] ifelse curiosity > curiosity-threshold [ buy-books ] [ move ] end ; Readers move about randomly and carry their books with them. to move rt random 50 lt random 50 fd 0.5 end ; Reader look for books to buy. The decision to purchase a book is based on ; a simple randomization of the books' appeal. to buy-books if my-seller != nobody [ face my-seller ] fd 1 if count booksellers in-radius seller-radius > 0 [ let temp-list [book-list] of self let books-to-buy manuscripts in-radius seller-radius with [ ; creates agentset of nearby books copies-on-the-shelf > 0 and ; must be owned by bookseller not member? title temp-list and (appeal + random-float 1 - random-float 1) >= price and ; appeal (randomly adjusted) must be higher than price price <= [money] of myself ; reader must have enough money ] let chosen-book one-of books-to-buy ; reader chooses one of the eligible books ifelse chosen-book != nobody [ let chosen-seller [my-publisher] of chosen-book set book-list fput [title] of chosen-book book-list set number-of-books length book-list set curiosity 0 ask chosen-seller [ set capital capital + [price] of chosen-book ] ; booksellers account is increased ask chosen-book [ set earnings earnings + price set copies-on-the-shelf copies-on-the-shelf - 1 ] ] [ set my-seller one-of booksellers ] ] end ; Booksellers check their inventory. to manage-inventory set capital capital - overhead set career-span career-span + 1 set min-title-diversity abs capital / 100 set my-manuscripts manuscripts with [my-publisher = myself] ask my-manuscripts [update-mss] if count my-manuscripts with [viable = true] <= min-title-diversity [ acquire-copy ] if count my-manuscripts with [copies-on-the-shelf > 0] < min-title-diversity [ print-mss ] end ; When sitting on the shelf, books lose appeal over time. to update-mss set appeal appeal - depreciation-rate if earnings >= expenses [ set viable true set shelf-time 0 ] if expenses > earnings [ set viable false set shelf-time shelf-time + 1 ] if shelf-time > book-age-threshold [ ask my-publisher [ set capital capital + ([price] of myself * pulp-rate) ] die ] if failed-solicitations > 5 [ die ] if appeal < 0 [ die ] end ; Bookseller creates a new title. to acquire-copy hatch-manuscripts 1 [ set size 1 set color 25 + random-float 4 set title random-float 100 ; The title create an identifier that can be inherited by copies set viable true set appeal 1.5 - random-float 1 set my-publisher myself set price [price-target] of myself - random-float .5 set depreciation-rate 0.01 - random-float .009 set book-age-threshold 700 - random 600 ] end ; Manuscripts "hatch" copies of themselves as books. When manuscripts hatch books ; those books retain the original's title, appeal, and price. to print-mss let chosen-manuscript one-of my-manuscripts with [ viable = true ] if chosen-manuscript != nobody [ set capital capital - (fixed-cost + ([price] of chosen-manuscript * (preferred-print-run * per-unit-cost))) ask chosen-manuscript [ set expenses expenses + (fixed-cost + ([price] of chosen-manuscript * ([preferred-print-run] of myself * per-unit-cost))) set copies-on-the-shelf copies-on-the-shelf + [preferred-print-run] of myself ] ] end ; Booksellers check to see if they have gone bankrupt. to check-accounts if capital < -200 [ ask my-manuscripts [ die ] die ] end
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File | Type | Description | Last updated | |
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Booktrade.png | preview | Preview for 'Booktrade' | over 10 years ago, by Michael Gavin | Download |
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