Triangular Plot

A Triangular Plot is a graph of 3 variables. It is most often used in geologic studies to show the relative compositions of soils and rocks, but it can be more generally applied to any system of three variables.

http://www.dplot.com/triangle_plot.htm

Wind Rose

The windrose chart is named for charts of wind speed and direction. Windrose charts are a type of histogram which are useful when the extreme values of the histogram's midpoint variable are related. Typical applications include histograms involving direction, clock time, or other cyclical values.

http://support.sas.com/documentation/cdl/en/graphref/59607/HTML/default/a003117074.htm

Climograph

A climograph is a graphical depiction of the monthly precipitation and temperature conditions for a selected place. Precipitation is shown by the bar graph. A line graph depicts temperature.

http://www.uwsp.edu/geo/faculty/ritter/glossary/a_d/climograph.html

Population Pyramid

Population Pyramids are graphs that show the distribution of population by age and sex.

This Population Pyramid illustrates the population distribution of the Turks and Caicos Islands.

http://www.census.gov/cgi-bin/ipc/idbpyrs.pl?cty=TK&out=s&ymax=300&submit=Submit+Query

Scatterplot

A scatterplot is a useful summary of a set of bivariate data (two variables), usually drawn before working out a linear correlation coefficient or fitting a regression line. It gives a good visual picture of the relationship between the two variables, and aids the interpretation of the correlation coefficient or regression model.

Each unit contributes one point to the Scatterplot, on which points are plotted but not joined. The resulting pattern indicates the type and strength of the relationship between the two variables.

http://www.stat.yale.edu/Courses/1997-98/101/scatter.htm

Index Value Plot

An Index Value Plot is another type of visualization map. An index value (not an absolute value) is plotted on a line graph.

This Index Value Plot shows real-time stream flow for the United States over the past 45 days (October - December 2008), and can be found at http://water.usgs.gov/waterwatch/?m=real&w=plot

Lorenz Curve

A graph for showing the concentration of ownership of economic quantities such as wealth and income; it is formed by plotting the cumulative distribution of the amount of the variable concerned against the cumulative frequency distribution of the individuals possessing the amount.

http://www.answers.com/topic/lorenz-curve