Index Value Plot

http://waterwatch.usgs.gov/index.php?id=real&sid=w__plot&r=nc

An index value plot is similar to a line plot but instead of absolute values, data is plotted as an index as the name suggests. In this map, we can see the average stream flow in North Carolina over a period of 45 days on a wet/dry scale with 1 being the driest and 7 being the wettest.

Population Profile

http://www.japanfocus.org/-Glenda_S_-Roberts/3450

Population profiles show numbers of people in a population as a function of their age. The population profiles above show the number of people in millions in each age group of five year increments. By comparing these three population profiles we can see that the distribution of ages will shift from a high population of younger people in 1950 to a slightly more even distribution in 2050.

Correlation Matrix

http://www.medscape.com/viewarticle/571448

A correlation matrix is an easy way to display the correlation value, r, between all variables in a set of data. This correlation matrix shows the correlations of different cognitive abilities in adults with HIV.

Similarity Matrix

http://www.biomedcentral.com/1471-2164/8/353/figure/F5?highres=y

A similarity matrix is used to express a variables similarity to another. In this matrix, different gene expressions are compared to each other. The darkest red symbolize the strongest similarity while the white represents no similarity. Everything in between is graded on a monochromatic scale.

Stem and Leaf Plot

http://hci.stanford.edu/jheer/files/zoo/

Stem and Leaf plots are a method of displaying numerical data where the stem column on the left represents the first digit and the leaf rows on the right represent the next digit associated with the stem. This type of plot, like the histogram, makes the distribution of numbers more clear and makes it easier to recognize the frequency and mode.

Box Plot

http://www.itl.nist.gov/div898/handbook/eda/gif/boxplot0.gif

Box plots graphically display data by their quartiles. The lowest data point being the minimum and the highest being the maximum, the box then shows the spread between the first and third quartile and the line in the middle is the median. In this graph, four box plots and displayed on the same graph so that the four machines could be compared against each other.

Histogram

http://www.statcan.gc.ca/edu/power-pouvoir/ch9/histo/5214822-eng.htm

Histograms are used to display the distribution of continuous data such as height, weight, salary, etc. If the data were categorical the bars would be separated but since the values are continuous, the bars are together. each bar represents the frequency at which the phenomena occurs in each range along the x axis.

Star Plot

http://www.nehu.ac.in/iqac/quality_radars.html

Star plots, more commonly known as radar charts, are for plotting multivariable data. Each variable is represented by an equal spoke (A-F) and the data points are plotted along each spoke. The data points are then connected to gauge the overall magnitude of the data. This technique is commonly applied to quality assessment so one could improve something with multiple standards.

Triangular Plot

http://geology.about.com/od/sediment_soil/ss/Soil-Classification-Diagram.htm

Triangular plots also known as ternary plots are used to plot three variables against each other that sum to a constant. It is commonly used in the physical sciences to show three different parts of a whole such as above. This triangle was presented to me in my physical geography class displaying the different percent concentrations of clay, sand, and silt that make up different loams.

Windrose

http://www.erh.noaa.gov/bgm/aviation/windroses/windrose.shtml

A windrose plot is used by meteorologists to diagram wind frequency and strength from various directions in a given area. This windrose is for Binghampton, NY. The colors represent varying levels of wind speed. These diagrams are commonly used at airports for their usefulness in demonstrating average wind patterns.

Climograph

http://www.colorado.edu/geography/extra/geogweb/bouldercreek-2/preview/page2.html

A climograph is a combination of multiple graph types to convey change of climate factors over time. In this particular graph, both line and bar graphs are used to show the change in monthly average precipitation and temperature in Boulder, Colorado over the course of a year.

Scatter Plot

http://www.gardenersown.co.uk/education/lectures/r/graphs2.htm

Scatter plots are used to graph data obtained from an experimenter to show the correlation between  independent and dependent variables. The independent variable is the variable that the experimenter controls, in this case it is speed, and the dependent variable is the data collected at each speed tested. After it is plotted, we can either see a positive correlation, shown above, a negative correlation or no correlation. It is important to remember however that correlation does not prove causation.

Accumulative Line Graph

http://www.unc.edu/~nielsen/special/s2/s2.htm

An accumulative line graph otherwise known as a Lorenz Curve is used to show the distribution of wealth. The perfectly diagonal line represents perfect equality of wealth. The curved line beneath it represents the inequality of wealth distribution by graphing what percentage of the population posses what percentage of the nation's total wealth.

Bilateral Graph

http://www.medscape.org/viewarticle/576121_2

Bilateral graphs compare two different but related sets of data on the same graph. They can be displayed as many different types of graphs including but not limited to line graphs and bar graphs. The bilateral line graph shown above compares the volume of right and left vestibular schwannoma tumors before and during treatment.

Nominal Area Choropleth Map

http://www.censusscope.org/us/map_common_race.html

This choropleth map is considered to be nominal area because the information on the map is non numerical. Instead the data is categorical, showing which demographic population is greater than the national average in each county of the United States.

Unstandardized Choropleth Maps

http://www.geogonline.org.uk/as_g2_popdensitymaps.htm

Unstandardized choropleth maps present enumerated data in the raw form rather than averaging it or gaining a percentage or ratio. This maps displays the population density across the world in the number of persons per square kilometer.

Standardized Choropleth

Standardized choropleth maps are thematic maps that present analyzed data as ratios or percentages if you look at the keys in the bottom left corners of the images above. These maps present the percent of population change from 1960 to 1970 by county.

Univariate Choropleth maps

http://eps.mq.edu.au/courses/GEOS219/choropleth.htm

Univariate choropleth maps are generic thematic maps that only display one statistical variable using chromatic shading of distinctly bordered areas. In this map, fertility rates are represented with higher rates being a darker shade on the grayscale. We can see geographic patterns very easily this way.

Bivariate Choropleth Maps

http://www.geo.unizh.ch/~annal/Choropleth%20maps.html

Bivariate choropleth maps combine two different variables on the same map by plotting the data on a two color plot, one color scale for each variable. While this type of map is good for synthesizing related variables to look for geographic patterns, sometimes the readability of the maps are ineffective.

Unclassed Choropleth Map

http://indiemapper.com/app/learnmore.php?l=choropleth

Unclassed choropleth maps the data is plotted along a monochromatic color scale and each data point is assigned a different color as opposed to grouped intervals. Unclassed choropleth maps are better for ranking larger data sets so that overall patterns can be seen.

Classed Choropleth Map

http://indiemapper.com/app/learnmore.php?l=choropleth

Classed choropleth maps used to indicate thematic phenomena in enumerated units. In the map above, values are displayed as intervals in and increasing chromatic scale. Enumerated data is used in order to form distinct boundary lines on the map. If we were to use thematic data such as soil classes, diseases, or age demographics because the boundaries lines would be indistinguishable.

Range Graded Proportional Circle Map

http://www.geog.ucsb.edu/~jeff/gis/proportional_symbols.html

Range graded proportional circle maps are a type of proportional circle map that displays the quantity of the variable on a predetermined scale of circles which are indicated in the key. Each circle represents a range of numbers rather than a specific value so the number of internet users could fall anywhere within 2 million people.

Continuously Variable Proportional Circle Map

http://elections.nytimes.com/2008/results/president/map.html

A continuously variable proportional circle map is similar to a proportional circle map however the circles don't correspond to set values, instead the vary directly proportional to the quantity of the variable. Also, as depicted in the map above, they can display multiple variables. The red represents votes for McCain while the blue represents votes for Obama for each county.

DOQQ

https://www.lib.ncsu.edu/gis/doqq.html

DOQQ stands for digital orthophoto quarter quadrangle. DOQQs are digital aerial photographs in which the pixels are aligned with longitude and latitude lines. These can also be satellite images. but regardless they strictly cover 3.75 minutes by 3.75 minutes.

DEM

http://www.jpl.nasa.gov/news/news.php?release=2010-053

A digital elevation model is a three dimensional rendering of a geographic surface. This image is a DEM of a small area of the Mojave Crate on Mars. Digital elevation models can be obtained using several methods including LIDAR, mentioned earlier in this blog, or stereo photogrammetry like the image above. Some applications of DEMs are global positioning systems, geographic information systems, engineering and infrastructure design, intelligent transportation systems, etc.

LIDAR

http://www.noaanews.noaa.gov/stories/s798b.htm

Lidar is a mapping technique where a laser is projected onto the Earth's surface and reflected back and analyzed to create a composite image. This image is a Lidar composite of Ground Zero in New York City. Lidar can also be used in archaeology to plan excavations, agriculture to create topographic maps of fields, or even to generate rapid topographic maps for automated vehicles.

Doppler Radar

http://www.noaanews.noaa.gov/stories2004/s2311.htm

A doppler radar map displays weather the motion of precipitation by bouncing a microwave signal off of the water droplets. Commonly used in weather reporting, meteorologists can display the movement of a storm front or hurricane such as the one depicted in this image of Florida.

B&W aerial photography

https://lta.cr.usgs.gov/NAPP

Black and White aerial photography is similar to infrared aerial photography but the film uses the full visible color spectrum, producing photos on a grayscale.

Infrared Aerial Photo

https://lta.cr.usgs.gov/NAPP

Infrared aerial photographs are photos taken on a film that is sensitive to the red and green portion of the color spectrum. In infrared photography, vegetation appears as red because it is highly reflective on that color spectrum. Infrared aerial photography has limitless surveillance, military and ecological applications.

Statistical Map

http://www.cdc.gov/pcd/issues/2007/oct/07_0091.htm

Statistical maps are any maps in which a variation in the quantity of a variable is depicted. Usually denoted by varying colors. In some statistical maps such as the one shown above, mapping the percentage of individuals living in poverty in the U.S., the incremental quantities are matched to a chromatic scale in which a darker shade of the color denotes a higher value.

Cartogram

http://www-personal.umich.edu/~mejn/cartograms/

Cartograms are maps that take a thematic variable and distort the geometric area of boundaries on the map to demonstrate the quantity of that variable. Some common thematic variables include population, such as shown on the map above, oil, voting, GDP, or debt. Notice that the countries with a larger population are expanded dramatically larger.

Flow Map

http://www.lib.utexas.edu/maps/texas.html

Flow maps combine maps and flow charts to show the movement and distribution of a product or variable. This specific map shows the distribution of freight truck flow across the U.S.. Flow maps such as this one usually depict how much of the variable is being moved, indicated by line thickness.

DLG

https://www.e-education.psu.edu/natureofgeoinfo/c7_p7.html

Digital Line Graphs are maps derived from information gathered by the USGS. DLGs can be broken down to nine layers: Public Land Survey System which shows townships, Boundaries such as state, county, city etc. Transportation (red lines on the map above) which includes roads and railways. Hydrography shows water (blue lines on the map above) and Hypsography (brown lines) show contour of land. Non-vegetative features, man-made features and vegetative surface coverage are three more layers and the last layer is survey control or markers.

DRG

http://libremap.org/data/

Digital Raster Graphics are scanned images of USGS topographic paper maps for use on a computer. They are stored as a *.tiff file and typically used in geographic information system applications. There are several databases on the internet that contain free DRGs from every state in the US.

Isopleth

http://www.flutrackers.com/forum/showthread.php?t=132504

Isopleth maps depict variables that can not be specified at a given point but must be over a larger area. This specific map is showing the concentrations of swine flu related deaths in California with the darker reds representing higher number of deaths. Isopleth maps can be manipulated though by changing the isolines which would in turn change the density.

Isopach

http://pubs.usgs.gov/of/2003/ofr-03-037/htmltext/introduc.htm

Isopach maps are isolinear maps that depict equal areas of geological thickness. These maps can be particularly useful in the study of fault lines, sediment, volcanoes, or structural geology.

Isohyets

http://www.water.gov.au/WaterAvailability/Whatisourtotalwaterresource/Rainfalldistribution/index.aspx?Menu=Level1_3_1_2

Isohyets depict the distribution of precipitation on a map with isolines. Each isoline represents where two different intervals of average precipitation meet.

Isotach

http://www.atmos.washington.edu/~mcmurdie/oct96/

An Isotach map is a type of isoline or contour map that shows the joining points of constant wind speed, also commonly used to interpret and predict weather patterns.

Isobars

http://people.ysu.edu/~wrbuckler/Weather/wxsites.html

Isobaric maps are used to depict the changes in average atmospheric pressure across an area. The curved lines each represent a different barometric pressure compared to that of sea level rather than surface pressure at that location. These types of maps can be useful in predicting future weather patterns and are commonly displayed during weather reports on the news channel.