Stem and Leaf Plot

Stem and Leaf Plot- An organized and systematic way of plotting large amounts of numerical data. Numbers are categorized based on leading numbers (stem), with remaining numbers placed horizontally next to these (leaf). The mean and median of the data set can usually be quickly identified in this way. This stem and leaf plot displays a data set of arm length in centimeters. The "stem" members represent the tens, and the "leaves" represent the ones' place. (http://myplace.frontier.com/~paulgriffith2/mathmodels/datacenters.html).

Box Plot

Box Plot- Also known as a box and whisker diagram. Provides a simple graphical summary of a data set, showing a measure of central location (median), average, and measures of dispersion (upper and lower quartiles). These are especially useful for comparing two or more data sets. Outlying data is indicated by points. This is a box plot of hits for a particular website in early 1999 based on days of the week. It can be noted that the average number of hits per day stayed consistently between 1,000 and 1,500 Monday through Friday, but dropped significantly on Saturday and Sunday (http://support.sas.com/rnd/app/da/new/daunivariate.html).

Histogram

Histogram- Displays tabulated frequency in a bar graph format. This simple histogram maps the frequency of high school students who get "x" hours of sleep per night. As it can be seen, the greatest frequency of high school students get 7 hours of sleep per night, while the lowest frequency of students get 5 hours Most high school students get more sleep rather than less (http://openhighschoolcourses.org/mod/book/view.php?id=206&chapterid=352).

Parallel Coordinate Graph

Parallel Coordinate Graph- A useful geovisualization tool for plotting and expressing relationships among many variables for a given subject of interest. Each variable is graphed on a vertical axis, and a data element is plotted a a connected set of points, one on each axis. This is a parallel coordinate graph describing car models released from 1970 to 1982, and contains their mileage (MPG), number of cylinders, horsepower, weight, and year they were introduced. It can be seen that generally, and inverse relationship exists between miles per gallon and number of cylinders. The more cylinders a car sports, the lower the mpg. A weaker relationship exists between number of cylinders and horsepower, though on the whole a car with fewer cylinders will fall on the lower end of the horsepower spectrum, and vise versa (http://www.fas.org/irp/imint/docs/rst/Sect16/Sect16_3.html).

Triangular Plot

Triangular Plot- A triangular figure plot useful discussing items of interest in the context of several different variables. Subjects are spatially placed on the graph according to their characteristics, and items that are most similar to each other are found to be closer together. This is a triangular plot of how a number of academic pursuits can be categorized. For example, politics involves a great deal of decision making, integration, and interpretation, and is more closely related to philosophy or religion than mathematics (http://www.fas.org/irp/imint/docs/rst/Sect16/Sect16_3.html).

Windrose

Windrose- A circular plot displaying frequencies of different wind directions and speeds.This is a windrose of wind patterns for an undisclosed location in North Carolina from July 2006 to December 2008. For example, the wind blew to the south 6.4% of the time. In total, the highest wind speeds recorded during this time, winds 10 to 20 mph, occurred only 4% of the time (http://alternativeenergyatunc.wordpress.com/2010/03/16/wind-roses/).

Climograph

Climograph- A graphic representation of the relation between temperature and precipitation plotted over monthly intervals. In this instance, precipitation levels (inches) are plotted on the left vertical axis, represented by the blue bars, and temperature (degrees Fahrenheit) is plotted on the right vertical axis, represented by the red line. This climograph of the average monthly temperature and precipitation measurements from 1930 to 2006 for the Lower Colorado River Planning Area shows the highest temperatures and precipitation occurring on in the month of August (http://www.census.gov/2010census/).

Population Profile

Population Profile- Population pyramids show age and sex distributions for a given time and region. Population demographics for Washington D.C. according to the US 2010 Census is given here. On the whole, the population seems to at first be growing (high fertility rate), but now stabilizing. Most individuals currently belong to the 20 to 30 year age group. Also, it appears there are more females than males for most age groups (http://www.census.gov/2010census/).

Scatterplot

Scatterplot- Graph used to express a relationship, where each dot represents an individual observation. A best fit linear line can also be drawn to make an expressed correlation more obvious, reflect an average, and develop an associated model. This is a simple scatterplot relating years of work experience to income earned, which in this case proves to be a strong positive correlation (http://blogs.mygns.ca/groups/math8v/weblog/d22e6/).

Index Plot Value

Index Value Plot- A line graph plotting index numbers instead of absolute numbers. Changes in a given variable over time relative to the initial year can easily be seen. This is accomplished by dividing values for subsequent years by the initial average and multiplying by 100. Here, average streamflow deviations from what is considered "normal" in the US from 2000 to 2010 are graphed, showing cyclic fluctuations from wet to dry conditions over the decade (http://waterwatch.usgs.gov/?m=real&w=plot).

Lorenz Curve

Lorenz Curve- A Lorenz curve shows the degree of inequality that exists in the distributions of two variables, and is often used in economics to illustrate the extent that income or wealth are distributed unequally in a particular society, as depicted in the graph above. The linear line would reflect an absolute even distribution of wealth. A Gini coefficient is a summary numerical measure of how unequally one variable is related to another, and can be calculated using the area of inequality between the line of perfect equality and the Lorenz curve (A) and the area underneath the Lorenz Curve (B). This downward bending of the Lorenz curve indicates that a small percentage of families earns a disproportionately large amount of the income (http://www.unc.edu/depts/econ/byrns_web/Economicae/Figures/Lorenz.htm).

Bilateral Graph

Bilateral Graph- A graph featuring two related variables and their overlap areas. This is a typical supply and demand bilateral graph showing the interplay between supply and demand, resulting in states of product surplus and shortage in an economy (http://sworlandoblog.com/2008/04/01/orlando-has-the-most-number-of-vacant-homes/).

Nominal Area Choropleth Map

Nominal Area Choropleth Map- A choropleth map categorizing areal data at the nominal level. Intervals are qualitative, categorical, classified into groups, with no implicit ordering. Here, minority groups with the highest percent of each state's population represent the intervals (https://courseware.e-education.psu.edu/courses/geog482/policies.shtml).

Unstandardized Choropleth Map

Unstandardized Choropleth Map- A choropleth displaying areal data that is not areally averaged (data is not in ratio or percentage form). This unstandardized choropleth map showing the Hispanic population in each of Missouri's counties in 2008 provides data in simple numerical intervals (http://www.missourieconomy.org/newsletter/hispanic_pop2008.html).

Standardized Choropleth Map

Standardized Choropleth Map- A type of choropleth map displaying areal data that has been areally averaged (data is expressed as a ratio or percentage). This standardized choropleth of population in a given area is divided into quantile (equal number of counties in each class) intervals based on population per enumeration area (http://www.directionsmag.com/articles/choropleth-mapping-with-exploratory-data-analysis/123579).

Univariate Choropleth Map

Univariate Choropleth Map- Only one variable is measured over the areal units, in this case states in the US. The single variable measured here is the average number of males per 100 females in each state. This choropleth is also classed, standardized, and intervals are divided by equal step breaks (http://my.ilstu.edu/~jrcarter/Geo204/Choro/).

Bivariate Choropleth Map

Bivariate Choropleth Map- Displays two variables on a single map, and their geographical pattern, by combining two different sets of graphic symbols or color. In this way, a relationship can be more easily seen than a comparison between two univariate maps. This bivarate choropleth measures unemployment percentages and number of foreclosures as of October 2011 per state. From this map, it can be inferred that a positive correlation exists between unemployment rate and the number of foreclosures (http://mapyoda.wordpress.com/).

Unclassed Choropleth Map

Unclassed Choropleth Map- A choropleth map presenting areal data not grouped into smaller intervals. Mortality rate of infants between the ages of 0 and 1 in African countries are set on a continuous white-to-orange scale, resulting in as many intervals and there are areal units  (http://www.geos.ed.ac.uk/~mscgis/07-08/s0788692/).

Classed Choropleth Map

Classed Choropleth Map- Map of areal data, where data has been combined into smaller groups, or intervals. Four to seven intervals are typically used. This is a classed choropleth map displaying the percentage (standardized) of the population that was Hispanic/Latino per Florida county in 2000 according to the US Census. Data is grouped into five distinct intervals, based on natural breaks (http://my.ilstu.edu/~jrcarter/Geo204/Choro/Tom/).

Range Graded Proportional Circle Map

Range Graded Proportional Circle Map- Each circle represents a different value for the variable being considered, but only a set number of circles are used. In this instance, each circle represents the number of homes built before 1940 in each western US state at the time when this survey was conducted by the US Census Bureau in 1990. Only six circle sizes are used here (http://www.neiu.edu/~nerobert/391/cartographic.htm).

Continuously Variable Proportional Circle Map

Continuously Variable Proportional Circle Map- Each circle represents a different value for the variable being considered, and circles vary greatly in size (sizes are not limited to a set number). Circles in the above map show the raw-vote size of a candidate’s lead by county, color coded according to political party. The numerous amount of circle sizes included cannot be counted (http://www.maproomblog.com/2008/11/three_us_election_maps.php).

DOQQ

DOQQ- Digital Orthographic Quarter-Quads. These are aerial photographs that has been georeferenced
and orthorectified in order to remove distortions inherent to aerial photos, so as to transform them into accurate planimetric maps. DOQQs are smaller scale images, each covering one quarter of a quadrangle (four 1:12,000-scale DOQQs display the same area as one 1:24,000-scale DOQ), and are also raster formatted. In this orthophoto of an undisclosed river location, ground features are displayed in their true position, allowing for more accurate measurement of distance, areas, angles, and positions. Infrared imaging also provides greater contrast. Orthophotos are also useful because photos display features that may be omitted or generalized on maps, such as unofficial dirt roads and varying vegetation types in this case (http://www.geomart.com/products/geodata/doqq/index.htm).

DEM

DEM- Digital Elevation Model. File is georeferenced, in a raster format, and consists of terrain elevations for ground positions at regularly spaced horizontal intervals. USGS raw DEM has 30- x 30-meter resolution (the size of each pixel). This is a DEM of the summit area of the Mauna Kea Volcano, Hawaii. A three-dimensional image has been rendered using elevation data to bring out relief (http://vterrain.org/Hawaii/Structures/observatories.html).

DLG

DLG- Digital Line Graph. These images are georeferenced, raster formatted, and contain digital vector data, in that map features are stored as lines (arcs), points, and areas (polygons). DLGs are derived from hypsographic data (contour lines) using USGS 7.5-minute, 15-minute, 2-arc-second (30- by 60-minute), and 1:2 million-scale topographic quadrangle maps. The 7.5- and 15-minute DLGs are within the large-scale category; the 2-arc-second DLGs are within the intermediate-scale category, and the 1:2 million-scale DLGs are within the small-scale category. From this DLG of San Francisquito Creek and the surrounding area, features such as waterway networks (hydrography), topography, road networks, boundaries, and utility lines can be seen (http://geography.wr.usgs.gov/sfcreek/dlg.html).

DRG

DRG- Digital Raster Graph. Created through a Geographic Information System (GIS), this is a scanned image of a US Geological Survey (USGS) standard series topographical map, including all map collar (original map border) information. These are georeferenced to the surface of the earth, the Universal Transverse Mercator projection, and the State Plane Coordinate System. Information is scanned at a minimum resolution of 250 dots per inch. Cartographic data is recorded, stored, and processed in a cell or pixel (raster format). Each map covers a quadrangle (quad), four-sided area of 7.5 minutes of latitude and 7.5 minutes of longitude. Quads can be combined to form larger maps. This is a DRG of Emerald Bay in Lake Tahoe, communicating topography, location, and physical features of the area (http://tahoe.usgs.gov/GIS.html).

Bathymetric Map

Bathymetric Map- A type of hypsometric and isoline map, contour lines connect points of equal sea floor elevation. This bathymetric map shows floor elevations surrounding Gull Island in Lake Michigan (http://mappery.com/Gull-Island-Bathymetric-Map).

Isobar Map

Isobar Map- A type of hypsometric and isoline map, contour maps connect point of equal air pressure. Patterns of air pressure (mb) across the continental US are shown here, and areas of high and low pressure systems are indicated (http://www.ametsoc.org/AMSEDU/dstreme/extras/usr_guide/Pressure.html).

Isopach Map

Isopach Map- A type of hypsometric and isoline map, contours connect points of equal rock or sediment thickness. This map shows sediment thickness of the Rio Blanco tephra deposit from the Active Crater of the Rincon de la Vieja volcano approximately 3,500 years Bp. This can also be classified as a choropleth map, as varying regions of sediment are divided into intervals and color coded accordingly (http://www.geo.utexas.edu/faculty/barker/kempter/rbtephra.html).

Isohyet Map

Isohyet Map- A type of hypsometric and isoline map, contour lines connect points of equal rainfall values. Here, lines connect equal average rainfall values (mm) on the Hawaiian island of Kaua'i for the month of October. Average rainfall increases towards the center of the island, with increasing elevation (http://rainfall.geography.hawaii.edu/downloads.html).

Isotach Map

Isotach Map- A type of hypsometric and isoline map, contour lines connect equal wind speed values. This is a map of wind speed and direction in northern Florida and southern Alabama and Georgia (http://www.intellicast.com/National/Wind/WINDcast.aspx?location=USFL0479).

Cartographic Animation

Cartographic Animation- The application of animation, either computer or video, to add a temporal component to a map displaying change in some dimension, usually over time. This animation illustrates seasonal changes in global average temperatures (http://uwacadweb.uwyo.edu/JSHINKER/animations/global/gifs/tmp2m_web.gif).

LIDAR

LIDAR (Light Detection and Ranging)- A type of active remote sensing (generates its own electromagnetic radiation). Uses a laser (light amplification by stimulated emission of radiation) which is transmitted from a narrow-band sensor (receives a limited range of wavelengths) to the observed object, then back to the sensor. Can record elevation to centimeter accuracy. This LIDAR image of the former World Trade Center was taken to indicate elevation of the remaining rubble for clean-up purposes (http://www.noaanews.noaa.gov/stories/s798.htm).

Doppler Radar

Doppler Radar- Based on the Doppler effect, this radar system uses a transmitter to emit microwave radiation and a directional antennae to receive and measure the time of arrival of reflected pulses from distant objects. An important component of meteorological  forecasting, Doppler radar creates an atmospheric profile of clouds, including their reflectivity (size and type of particles in the air, indicate precipitation type), velocity (speed and direction of the air relative to the radar station), and intensity of precipitation. Here, Doppler radar creates an image of Hurricane Charley over central Florida, showing its location, wind and associated cloud and precipitation movement, precipitation intensity, and DBZ values (equate to approximate rainfall rates) (http://kwilklab.wordpress.com/author/kwilk1984/).

Black and White Aerial Photo

Black and White Aerial Photo- A type of passive remote sensing that uses a broad-band sensor. Black and white emulsion is sensitive to approximately the same wavelength as the human eye, so artificial coloring is not necessary (unlike infrared photos). This is a black and white aerial view of the football stadium at the University of Washington  (http://www.allposters.com/-sp/University-of-Washington-Black-and-White-Aerial-of-Husky-Stadium-Posters_i9086386_.htm).

Infrared Aerial Photo

Infrared Aerial Photo- A type of passive remote sensing. Naturally-generated radiation
that is emitted or reflected is measured and converted to an image using a broad-band sensor (receives radiation of many wavelengths and composites them into a single signal). Infrared emulsion is sensitive to wavelengths that are outside of the range of human vision, so false color is used. Differences in vegetative types are more easily distinguished in infrared photos versus black and white emulsion photos, as well as contrasts between land and water. This is an infrared aerial photo of Rome, differences between vegetation are pronounced by red and pink shades (http://cae2k.com/photos-of-roma-0/infrared-aerial-photo.html).