Cartography Essay

How do the conventional choropleth technique and the unclassed choropleth technique differ? The conventional chorophleth technique groups the data values into classes with an unique areal symbol; in the unclassed choropleth technique each value is symbolized by its own unique areal symbol. When employing the conventional choropleth technique, approximately how many classes should you use? In the conventional choropleth technique you should use 4-6 classes.   If you had a shapefile consisting of states of the United States, how would you create a new shapefile of only the New England states? To create a new shape file for New England you should right-click countries in the â€Å"Table of Contents†, select â€Å"Data†, then â€Å"Export Data†. â€Å"Export data† window will open, where you should click the catalog browser button to select where you want to save your file. You should name the file â€Å"New England† and click â€Å"ok†. If your attribute table contained two fields, Population and Area (in square miles), how would you create a choropleth map of the derived value of Population Density (persons per square mile)? To create a choropleth map with two different fields you have to normalize your informations. You should open the proprieties window and with the population field select from the normalization list. You have to create a new value by dividing the value field (area) by the normalization field (population). Then you should right-click on one of the ranges then select Format Labels, and in the Number Format window, select Rate. In the numeric option window you should put 1 decimal rounding. Check the Pad with zeros checkbox, and finally make a color selection. What are the classification schemes available in ArcMap? There are six automatically-calculated classification schemes in ArcMap: Equal Interval, Defined Interval, Quantile, Natural Breaks (Jenks), Geometrical Interval, and Standard Deviation. When symbolizing your areas, how can you view the names of the available color ramps? You should right-click on the color ramp and deselect Graphic View from the context menu, and then click on the color ramp to view the drop-down list. How can you automatically round the legend values to two decimal places? You have to check the â€Å"Pad with zeros† checkbox in the Numeric Option window (Layer properties>Number Format>Numeric Option). How can you view descriptive statistics and a histogram of your data from within the Symbology tab of the Layer Properties window? To view a descriptive statistic and histogram from the symbology tab of the layer properties window you should click on the â€Å"classification† button and a classification window will open showing the Classification Statistics box, which shows the descriptive statistics for the values being classified and a histogram of the data which includes lines showing the upper limit of each class. How do you resize your data frame to specific dimensions in the layout? You can resize your data frame to specific dimensions in the layout by clicking and dragging one of the sizing or adjusting the size of the frame in the â€Å"Data Frame Properties† window. In choropleth mapping, and thematic mapping in general, what is commonly used as the legend title? Map titles for thematic maps generally have one or more of the following items: (1) the subject matter of the map, (2) the location being mapped, and the (3) year or time period of the subject matter.