spaghetti plot

Spaghetti diagrams have been used to study why butterflies are found where they are, and to see how topographic features (such as mountain ranges) limit their migration and range.{{cite book|url=https://books.google.com/books?id=Oa5m8gZcGjMC&pg=PA103|page=103|title=The Butterflies of North America: A Natural History and Field Guide|author=James A. Scott|year=1992|publisher=Stanford University Press|isbn=978-0-8047-2013-7}} Within mammal distributions across central North America, these plots have correlated their edges to regions which were glaciated within the previous ice age, as well as certain types of vegetation.{{cite book|url=https://archive.org/details/handbookofmammal0000jone|url-access=registration|pages=[https://archive.org/details/handbookofmammal0000jone/page/52 52]–55|author1=J. Knox Jones |author2=Elmer C. Birney |title=Handbook of mammals of the north-central states|year=1988|publisher=University of Minnesota Press|isbn=978-0-8166-1420-2}}

File:Nov192001h5spaghetti5640m.png

Within meteorology, spaghetti diagrams are normally drawn from ensemble forecasts. A meteorological variable e.g. pressure, temperature, or precipitation amount is drawn on a chart for a number of slightly different model runs from an ensemble. The model can then be stepped forward in time and the results compared and be used to gauge the amount of uncertainty in the forecast. If there is good agreement and the contours follow a recognizable pattern through the sequence, then the confidence in the forecast can be high. Conversely, if the pattern is chaotic, i.e., resembling a plate of spaghetti, then confidence will be low. Ensemble members will generally diverge over time and spaghetti plots are a quick way to see when this happens.

Spaghetti plots can be a more favorable choice compared to the mean-spread ensemble in determining the intensity of a coming cyclone, anticyclone, or upper-level ridge or trough. Because ensemble forecasts naturally diverge as the days progress, the projected locations of meteorological features will spread further apart. A mean-spread diagram will take a mean of the calculated pressure from each spot on the map as calculated by each permutation in the ensemble, thus effectively smoothing out the projected low and making it appear broader in size but weaker in intensity than the ensemble's permutations had actually indicated. It can also depict two features instead of one if the ensemble clustering is around two different solutions.{{cite web|url=http://www.emc.ncep.noaa.gov/gmb/ens/spaghetti/spag_frame.htm|title=NCEP Medium-Range Ensemble Forecast (MREF) System Spaghetti Diagrams|author=Environmental Modeling Center|date=2003-08-21|publisher=National Oceanic and Atmospheric Administration|accessdate=2011-02-17|author-link=Environmental Modeling Center}}

Various forecast models within tropical cyclone track forecasting can be plotted on a spaghetti diagram to show confidence in five-day track forecasts.{{cite book|url=https://books.google.com/books?id=ZNroiySUreQC&pg=PT31|author1=Ivor Van Heerden |author2=Mike Bryan |title=The storm: what went wrong and why during hurricane Katrina : the inside story from one Louisiana scientist|year=2007|publisher=Penguin|isbn=978-0-14-311213-6}} When track models diverge late in the forecast period, the plot takes on the shape of a squashed spider, and can be referred to as such in National Hurricane Center discussions.{{cite web|url=http://www.nhc.noaa.gov/archive/2007/ep02/ep022007.discus.003.shtml|title=Tropical Depression Two-E Discussion Number 3|author=John L. Beven, III|date=2007-05-30|accessdate=2011-02-17|publisher=National Hurricane Center}} Within the field of climatology and paleotempestology, spaghetti plots have been used to correlate ground temperature information derived from boreholes across central and eastern Canada.{{cite book|url=https://books.google.com/books?id=w2Jye1p-MBEC&pg=PA76|page=76|title=Borehole climatology: a new method on how to reconstruct climate|author1=Louise Bodri |author2=Vladimír Čermák |year=2007|publisher=Elsevier|isbn=978-0-08-045320-0}} As in other disciplines, spaghetti diagrams can be used to show the motion of objects, such as drifting weather buoys over time.{{cite book|page=341|url=https://books.google.com/books?id=Ax2d94PODgIC&pg=PA341|title=The turbulent ocean|author=S. A. Thorpe|year=2005|publisher=Cambridge University Press|isbn=978-0-521-83543-5}}

File:Workflowspaghetti.jpg movement through a facility in the search for a glucometer]]

Spaghetti diagrams were first used to track routing through a factory.{{cite book|url=https://books.google.com/books?id=0p6ccHR5b6QC&pg=PA97|page=97|author=William A. Levinson|title=Beyond the theory of constraints: how to eliminate variation and maximize capacity|year=2007|publisher=Productivity Press|isbn=978-1-56327-370-4}} Spaghetti plots are a simple tool to visualize movement and transportation.{{cite book|url=https://books.google.com/books?id=gJFJ1A7aR-8C&pg=PA127|page=127|title=How to Implement Lean Manufacturing|author=Lonnie Wilson|year=2009|publisher=McGraw Hill Professional|isbn=978-0-07-162507-4}} Analyzing flows through systems can determine where time and energy are wasted, and identify where streamlining would be beneficial. This is true not only with physical travel through a physical place, but also during more abstract processes such as the application of a mortgage loan.{{cite book|url=https://books.google.com/books?id=4IklOX1KAEwC&pg=PA130|page=130|title=Supply Chain Management For Competitive Advantage|author=Rangaraj|isbn=978-0-07-022163-5|publisher=Tata McGraw-Hill|year=2009}}

Spaghetti plots can be used to track the results of drug trials amongst a number of patients on one individual graph to determine their benefit.{{Cite book |last=Hedeker |first=Donald R. |url=https://books.google.com/books?id=TRwucwebYMcC&pg=PA54 |title=Longitudinal data analysis |last2=Gibbons |first2=Robert D. |date=2006 |publisher=John Wiley and Sons |isbn=978-0-471-42027-9 |pages=52–54 |author-link2=Robert D. Gibbons}} They have also been used to correlate progesterone levels to early pregnancy loss.{{cite book|pages=2–4|url=https://books.google.com/books?id=Ny0Rs1PwRiQC&pg=PA2|title=Nonparametric regression methods for longitudinal data analysis|author1=Hulin Wu |author2=Jin-Ting Zhang |publisher=John Wiley and Sons|year=2006|isbn=978-0-471-48350-2}} The half-life of drugs within people's blood plasma, as well as discriminating effects between different populations, can be diagnosed quickly via these diagrams.{{cite book|pages=263–264|url=https://books.google.com/books?id=K-gT2_Ukk0QC&pg=PA264|author1=Johan Gabrielsson |author2=Daniel Weiner |title=Pharmacokinetic/pharmacodynamic data analysis: concepts and applications, Volume 1|publisher=Taylor & Francis|year=2001|isbn=978-91-86274-92-4}}

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{{reflist|2}}

{{commons category|Spaghetti plots}}

• [http://www.ncl.ucar.edu/Applications/tigge.shtml TIGGE Project at NCAR]

{{Visualization}}

Category:Graphic software in meteorology

Category:Climate and weather statistics

Category:Statistical charts and diagrams

Category:Metaphors referring to spaghetti