The PC-SIG Library 10

home *** CD-ROM | disk | FTP | other *** search

/ The PC-SIG Library 10 / The PC-Sig Library - Shareware for the IBM PC and Compatibles (PC-SIG)(Tenth Edition Disks 1-2804)(1991).iso / PC_SIGCD / 02 / 1 / DISK0219.ZIP / MANUAL.DOC < prev next >

Wrap

Text File | 1980-01-01 | 42KB | 835 lines

*********************************************************************** *********************************************************************** From the author: I am distributing MapMaker as user-supported software. Users are encouraged to copy and distribute the program and data sets on the following conditions: 1. The program and its data sets are not altered in any way. 2. No fee is charged for the copying and/or distribution of the same. Among the advantages of the "user-supported" approach is the ability of users to evaluate software without large and often risky financial investments. Obviously, the creation and support of software requires a substantial investment of time and effort. If you find MapMaker useful, a user's fee/registration payment of $55 is requested. Registered users will receive the following: 1. Any program and/or manual updates. 2. $25 for submission of new and useful polygon data sets. 3. Any or all new data sets from the library of data sets created by or received by the author. I've done my best to test the program and develop a clear and useful manual. Please read it carefully. I welcome notifications of any program "bugs", and will gladly and promptly respond to all questions about the program and/or data sets. Please direct payments, questions, or comments to: Paul R. Stayert 3141 GPA, Univ. of Fla. Gainesville, Fla. 32611 ************************************************************************ ************************************************************************ *********************************************************************** M a p M a k e r - USER'S MANUAL (C)Copyright Stayert, 1985 *********************************************************************** INTRODUCTION MapMaker produces two common forms of quantitative maps; CHOROPLETH (Area Coloring) and GRADUATED CIRCLE, on an IBM/PC color monitor, and if desired, in black and white on a matrix printer. Two versions of the program are available, requiring the following configurations: Version 2.1 (mm1.exe) Version 2.2 (mm2.exe) - IBM/PC with 128K RAM - IBM/PC with 128K RAM - 1 320K Disk Drive - 1 320K Disk Drive - DOS 2.0 - DOS 2.0 - Color Monitor - Color Monitor w/ adapter card w/ adapter card - Matrix Printer (optional) - Monochrome Monitor - Matrix Printer (optional) Any set of statistical values may be displayed for corresponding geographical areas. Map areas must be comprised of bounded units such as states, counties, census tracts, or areas delineated by the user. On any given map, only one variable is shown for each map unit. Choropleth maps display statistical variables by using a sequence of colors (maximum of 3). Circle maps represent data with proportionately- sized circles. Proper usage of both map forms is discussed in detail later in the manual. MapMaker can also save and later recall screen images without going through the create process. Directions and suggestions are provided on the screen throughout the program and it is possible for users who have little or no experience in mapping to produce maps. In order to produce statistically meaningful and visually effective displays, however, users should read the manual thoroughly prior to creating maps. APPLICATIONS Given the appropriate data sets, MapMaker has a great variety of applications, including scientific research, governmental planning, business and education. Researchers and planners often need to display and identify spatial patterns relating to, for example, social, economic, and environmental data. Business decisions often are based on similar types of information, and additionally, business analysts can map levels of activity and/or profit for specific territories. As an educational tool, MapMaker can be used as an exercise in the creation of quantitative maps. An understanding of the data sets can familiarize students with some of the fundamental aspects of computer-assisted mapping. Although the manual was written to facilitate use of the program, it also serves as a brief tutorial for choropleth and graduated circle mapping. If "hardcopy" is needed, maps can be printed in monochrome on matrix printers, or slides may be taken directly from the color screen. Some suggestions for slide-taking are offered in Appendix C. ----------------------------------------------------------------------- This manual is organized as follows: PART 1. discusses CHOROPLETH and CIRCLE maps and the type of data sets that are required as input. PART 2. discusses the steps involved in the creation of a CHOROPLETH map. This information is supplemental, for the most part, because directions are displayed on the monochrome screen throughout the creation process. PART 3. contains a similar type of information for the creation of GRADUATED CIRCLE maps. APPENDIX A. describes the formats for all data sets that can be used as input to MapMaker, and the procedure used to establish them. APPENDIX B. lists the names and descriptions of sample data sets that are provided with MapMaker in order to demonstrate the program. APPENDIX C. contains comments and suggestions for the running of MapMaker. ---------------------------------------------------------------------- PART 1. PROGRAM OVERVIEW 1-1 Locational Data MapMaker combines locational and statistical information in order to show the distributions of quantities of some variable, throughout a selected study area. Locational data may represent any area that is divided into sub-regions (polygons) such as the U.S. (by states), a state (by counties), a city (by census tracts), or even the offices in a floor plan. The sub-regions must be bounded or "closed", and there may be no more than 65 of them. MapMaker uses vector-type polygon data that must be digitized and entered into diskette data sets prior to the creation of a map. (Appendix A. discribes the format of all data sets.) ----------------------------------------------------------------------- 1-2 Statistical Data Each map unit (polygon) must have a corresponding statistical value. These values comprise the Statistical data set. Because the polygons represent map AREAS, corresponding statistical values must represent ENTIRE polygons, not merely a point or points within. For example, the population of an entire area (county or state), is an appropriate statistic. The population of a selected city or cities within the area, however, is NOT appropriate. Statistical values must be QUANTITATIVE. Each value should represent a quantity of some variable, such as the number of persons, the number of bushels of corn, or the average income of residents. Statistical data sets must contain numbers, not words. The dominant ethnic group in an area, for example, is a QUALITATIVE variable and therefore not appropriate. However, the total number or percentage of persons who belong to a selected ethnic group, is a QUANTITATIVE variable and would be appropriate. ----------------------------------------------------------------------- 1-3 Raw and Derived Values Quantitative data are either of two possible types, RAW or DERIVED, and therefore MapMaker offers two types of map display; CHOROPLETH and GRADUATED CIRCLE. Consider a situation where the Circle map is used to display "Total Population" for a selected area. If the polygon data set were a state (by counties), the total number of persons living in each county would be represented by a proportionately-sized circle that would be positioned in the center of each county. This type of data display is appropriate. Consider the same map area with unemployment statistics, where the circles would represent the percentage of the persons who were unemployed. Again, this is appropriate. In the case of Choropleth maps, however, each entire polygon is colored according to the quantity of a selected variable and therefore the SIZE, in addition to the COLOR of the polygon, comprise the visual message. One would expect a larger area to have more of any variable (all other things being equal). Smaller areas would tend to have fewer of a variable. Coloring polygons a "higher" or "lower" color because they are of a particular size to begin with, is a redundancy, resulting in a distorted visual message to the map reader. The use of DERIVED values, such as "Persons Per Square Mile" (statistic per area), eliminates the effect of the relative sizes of map areas, and provides a truer representation of the distribution of a variable throughout a study area. To summarize, Choropleth maps usually require DERIVED values, while Circle maps can show either type of data, although RAW values may be preferred. MapMaker can perform the conversion for Choropleth maps if the digitizing unit and scale of the original map are known. NOTE: If statistical values are already derived, such as percentages, then they should be treated as RAW values so that no further manipulation is done. ----------------------------------------------------------------------- 1-4 Center Points of Polygons In order to color map areas and position circles, MapMaker includes a function that calculates the center point (centroid) of each polygon. Occasionally, the calculated centroids are unusable because the shapes of some polygons cause the centroids to fall outside of the actual polygon areas. Consider the state of Florida, for example. The center point of the entire state would fall to the south of the panhandle and to the west of the peninsula, and therefore outside of the actual state boundaries. This results in errant coloring on Choropleth maps and misplaced circles on Graduated Circle maps. The alternative is the usage of a separate centroid data set. In addition to the correct coloring of map areas, for Choropleth purposes, it allows the preferred positioning of circles on Circle maps. (Appendix A. describes the exact format of all data sets.) ----------------------------------------------------------------------- 1-5 Map Size and Orientation MapMaker scales all maps to fit the available screen space, regardless of the size of the original map. Therefore, the more numerous the polygons, the smaller they will appear on the screen, and vice-versa. In order to maximize the size of maps on the color screen, two formats are used; Horizontal and Square. If the polygon data set is much longer in the horizontal dimension (the state of Tennessee, for example), the horizontal format is used, otherwise a more "squared" format is chosen. The decision is made internally and is not affected by the user-supplied directives. In addition to the altered position of the legend, the only difference between the two formats is the possibility of a longer legend caption in the horizontal format. ----------------------------------------------------------------------- ----------------------------------------------------------------------- PART 2. CREATING CHOROPLETH MAPS 2-1 Starting MapMaker If a matrix printer is to be used for printing maps, be sure to initialize the graphics printing mode by typing "graphics" while in DOS 2.0. Insert the MapMaker diskette and type "mm1" for a 1-monitor system, or "mm2" for a 2-monitor system. ---------------------------------------------------------------------- 2-2 Polygon Data Set Enter the name of the polygon data set to be used. Include the diskette drive designation if the diskette is not in the default drive. For example: b:flapan ----------------------------------------------------------------------- 2-3 Number of Polygons Enter the number of polygons in the polygon data set. This is the number of areal units (states, counties, census tracts, for example). ----------------------------------------------------------------------- 2-4 Origin of Digitizer The origin of polygon data sets (in terms of X and Y coordinates), may be either the upper left or lower left corner. If the origin is in the lower left corner, an inversion of the Y coordinate is performed by entering a "2". ----------------------------------------------------------------------- 2-5 Centroids Center points (centroids) may be either calculated or entered as a separate data set. (See section 1-4 for a complete explanation.) Include drive designation if necessary. ----------------------------------------------------------------------- 2-6 Statistical Data Set Enter name of statistical data set and drive designation, if needed. ----------------------------------------------------------------------- 2-7 Raw or Derived Statistical Values Choropleth maps usually require DERIVED values in order to be meaningful. If the statistical data set contains RAW (non-derived) values, MapMaker can perform the conversion if the digitizing unit and scale of the original map are known. (See section 1-3 for a complete explanation.) If the conversion is desired, (d is entered), then the following information is requested: a. A choice of either "Statistic divided by Area" or "Area divided by Statistic". Depending on the magnitude of statistical values and the actual size of the polygons, either choice may be practical. For example, in a sparcely-populated area, a map of "Square Miles per Person" (Area/Statistic) may avoid the very small numbers that would appear on a map of "Persons per Square Mile" (Statistic/Area). For most purposes, "Statistic/Area" data is preferable. b. The map scale. Enter the scale of the map that was used to create the polygon data set. c. The digitizing unit. Most digitizers use either "inches" or "centimeters". d. The map unit. This is the areal unit desired for the created map. For example, in the case of census tracts, "Acres" or "Hectares" may be more reasonable than "Sq. Miles" or "Sq. Kilometers". After the information is entered and calculated, the minimum and maximum derived values are shown. There is an option to respecify some of the information, in the event the magnitude of these numbers is not acceptable (usually because the numbers are too small). Obviously, the map scale and digitizing unit (b. and c.) should not be altered. ----------------------------------------------------------------------- 2-8 Legend Numbers The physical length of numbers used in Choropleth legends is limited to four spaces. If the maximum statistical value (whether Derived or Raw) is 9999 or less, there is no problem. If the maximum value were 23456, for example, a multiplication factor would be used. In this case, a "10 X" factor would reduce the maximum value to 2345 which would then fit as a legend number. Any factor used to reduce the magnitude of statistical values MUST be indicated in the map title or legend caption. ----------------------------------------------------------------------- 2-9 Number of Map Classes Choropleth map classes are the categories into which the statistical values are divided. Screen resolution and the number of colors available limit the maximum number of classes to three. If selected properly, three divisions of data can produce an effective display. ----------------------------------------------------------------------- 2-10 Selection of classes A Bar Graph on the color screen illustrates the values associated with all polygons, arranged in ascending order. When selecting class intervals, the following points should be considered: a. The minimum of class 1 should be equal to or lower than the minimum statistical value. The maximum of the highest class should be equal to or higher than the maximum statistical value. b. There should be no gaps between the maximum values of classes and the minimum values of following classes. c. Even or "rounded" numbers should be used for class minimums and uneven or "extended" numbers used for class maximums. Poorly selected legend values can by annoying and may complicate the use of legend information when interpreting map content. In the following example, the above mentioned rules are followed: ---------------------------- The minimum value is 6.4 The maximum value is 94.6 ---------------------------- Class 1 min? 6.0 Class 1 max? 29.9 Class 2 min? 30.0 Class 2 max? 59.9 Class 3 min? 60.0 Class 3 max? 94.9 ------------------------------------------------------------------ NOTE: Any values that fall outside of specified class ranges will not be assigned a class and the corresponding polygons will not be colored on the map. The non-coloring of areas that have low values (or values of 0) may be preferable at times. ---------------------------------------------------------------------- 2-11 Map Title and Legend Caption The title usually describes the map area and the statistical variable or "map theme". The title, along with an optional legend caption, may include the following information: 1. Map Area 2. Description of Statistical Data 3. Type of Derived Values (if values are derived) 4. Date of Statistical Data 5. Data Factor (if any) A legend caption may be used to provide additional information about legend values. If a data factor is used, it should be indicated in the legend caption, such as "(X 1000)". If no factor is used, the caption may contain the date or perhaps the type of derived statistical values, such as "1970-1980", or "1982 Data", or "Pers/Acre". The legend caption in the square map format (see section 1-5) is limited to nine spaces, but can be much longer in the horizontal format. ---------------------------------------------------------------------- 2-12 Selection of Map Colors Choropleth map classes can be represented by two sets of three foreground colors. Only one set can be used on any map and therefore up to three classes are possible. Either set or "palette" may be used with any of eight background colors. Most map readers are accustomed to the notion that "lighter means less" and "darker means more". Because map classes correspond to a numerical progression, an effective color scheme contains a visual progression of color. Palette 1 usually offers a good progression of color with White, Cyan, and Magenta used to color low, middle, and high classes, respectively. Palette 0 colors can also be effective. NOTE: An effective color scheme enables map readers to perceive the general distribution of data without constant reference to the legend. At first, it is probably a good idea to go through the viewing routine to see how the colors look in various combinations. When users become familiar with the colors, the viewing routine may be unnecessary, and colors can be selected immediately. --------------------------------------------------------------------- 2-13 Class Color Selection After selecting the palette and background colors, colors must be chosen for the individual map classes. When prompted for the color of each class, enter the number of the color (1, 2, or 3) from the palette that has been chosen. --------------------------------------------------------------------- 2-14 Table of Data Prior to the display of the map, a table of data is shown on the monochrome screen. Values for all polygons, whether derived or raw, are shown along with the classes into which they fall. The table may be printed on the matrix printer by pressing the SHIFT and PRTSC keys simultaneously. Pressing any other key produces the map. ---------------------------------------------------------------------- 2-15 The Sub-Menu After a map has been drawn on the color screen, it can be modified by the usage of a sub-menu that is accessed by pressing any key. It is unlikely that the first run of any map will be perfect and it is often preferable to alter some aspects of the map. The options include: 1. Change of color scheme 2. Change of class intervals 3. Change title/caption 4. Save map to file on diskette 5. Return to main menu 6. Exit program If a modification is needed that is not offered by the sub-menu, the create process must be redone by returning to the main menu. When the desired version of a map is produced, it can be recorded in two ways: 1. It may be saved as a screen file to a diskette (Sub-Menu #4). A filename must be specified, along with a drive designation, if necessary. The file can later be recalled and the saved map image can be displayed on the color screen without going through the create process. 2. It may be printed on a matrix printer. This may be done by pressing SHIFT and PRTSC immediately following the drawing of the map on the color screen (before going to the sub-menu). IMPORTANT: To print a map on the matrix printer, it is necessary to initialize the graphics printing mode. This is done by typing GRAPHICS while in DOS (before running the program). GRAPHICS is the name of a file on the DOS 2.0 disk. The file will be read but nothing visible will happen. The program can then be run and images on the color monitor can be printed on the matrix printer. (The GRAPHICS command may be included in an AUTOEXEC.BAT file.) NOTE: For Choropleth maps, the matrix printer produces images only in black and white. Choropleth classes may, however, be represented by a progression of grey tones. The grey tones correspond to particular colors used on the color screen, but the colors that make an effective color progression do not correspond to grey tones that are effective on matrix printer maps. In order to produce an effective grey tone progression on the printer, the colors of map classes must be respecified (sub-menu #1). The choice of background and palette is unimportant. However, the COLORS for map classes 1, 2, and 3, must be 1, 2, and 3, respectively. This produces a poor color progression on the color screen, but produces an effective sequence on the matrix printer. ----------------------------------------------------------------------- ----------------------------------------------------------------------- PART 3. CREATING GRADUATED CIRCLE MAPS 3-1 Starting MapMaker (see section 2-1) -------------------------------------------------------------------- 3-2 Polygon Data Set (see section 2-2) -------------------------------------------------------------------- 3-3 Number of Polygons (see section 2-3) -------------------------------------------------------------------- 3-4 Origin of Digitizer (see section 2-4) -------------------------------------------------------------------- 3-5 Centroids (see section 2-5) -------------------------------------------------------------------- 3-6 Statistical Data Set (see section 2-6) -------------------------------------------------------------------- 3-7 Legend Circles The legend on circle maps contains three circles that are used as references for estimating the values of circles on the map. Legend circles should range in size from a value at or near the minimum statistical value, to a value at or near the maximum statistical value. Values for legend circles should be even or "rounded". For example: ------------------------------------------- The minimum statistical value is 113 The maximum statistical value is 1464 Enter the value for the smallest circle 100 Enter the value for the middle circle 750 Enter the value for the largest circle 1500 ----------------------------------------------------------------------- 3-8 Circle Size (diameter) Circle size is often a matter of individual preference. Maps with fewer polygons are able to have larger circles without the severe overlapping that occurs on a map that has many (and therefore smaller) polygons. The best strategy is to try a size and later modify it if it is not appropriate. Overlapping may cause problems with some circles. ---------------------------------------------------------------------- 3-9 Circle Calculation (square root vs. other) The standard formula for calculating the area of circles involves square roots. Research in visual perception indicates that map readers tend to underestimate the area of large circles, relative to smaller ones. Use of a 1.75 root is a common alternative to using the square root. This has the effect of exaggerating the sizes of larger circles. Because the maximum diameter has already been specified, the exaggeration is accomplished by reducing the sizes of smaller circles. Obviously, this decision is very subjective and the use of any root between 1.7 and 2.0 may be considered reasonable. Experimentation is recommended. ----------------------------------------------------------------------- 3-10 Map Title and Legend Caption The map title should describe the map area and the nature of the statistical data. A legend caption may be used to describe further the statistical values or perhaps to indicate the date. The legend caption in the square format (see section 1-5) is limited to nine spaces, but can be longer in the horizontal map format. ----------------------------------------------------------------------- 3-11 Selection of Circle/Map Colors Unlike the selection of color for choropleth maps, colors for circle maps cannot be selected without going through the viewing routine. As with choropleth maps, any of eight background colors may be selected, but on circle maps, each of the two-color sets (palettes) is capable of four color combinations. Users are urged to follow the directions on the monochrome screen when selecting circle colors. ----------------------------------------------------------------------- 3-12 Table of Data A listing of polygons and associated values is shown on the monochrome screen prior to the display of a map. The table may be printed on the matrix printer by pressing the SHIFT and PRTSC keys simultaneously. Pressing any other key produces the map. ----------------------------------------------------------------------- 3-13 The Sub-Menu The sub-menu can be used to modify some elements of the map. It can be accessed by pressing any key after the map has been drawn. The map modification options include: 1. Change color scheme 2. Change circle size 3. Change legend values 4. Change title/caption 5. Save map to file on diskette 6. Return to main menu 7. Exit program If a modification is needed that is not offered by the sub-menu, the create process must be redone by returning to the main menu. As with Choropleth maps, circle maps may be saved as screen files or printed on a matrix printer (see section 2-15). ----------------------------------------------------------------------- ----------------------------------------------------------------------- APPENDIX A. FORMAT AND CREATION OF DATA SETS A-1 Format of Polygon Data Sets All data sets required by MapMaker are comprised of a sequence of data lines. The Polygon data set is by far the largest and most complex because it contains the entire framework of the map. Polygon data sets consist of points that form the boundaries of map areas, and are expressed in terms of X and Y coordinates. The conversion of map points to two- dimensional coordinates is called DIGITIZING. A reference point (origin) is established for X and Y measurements and when the map is positioned properly, each point can be referenced by a coordinate pair. The digitizer origin may be in the upper left or lower left corner. The measurement units usually are either inches or centimeters. A digitizing instrument or even an underlay of graph paper can be used to obtain coordinate measurements. The X coordinate measurement always increases from left to right, but the Y coordinate is inverted from one digitizer format to the other. MapMaker can use either orientation by performing a conversion when necessary. Boundaries of polygons that comprise maps are expressed by sequences of coordinate pairs, where each pair represents a point along the boundary. Points are determined by the person doing the digitizing and commonly are located in places where the boundary changes direction, or are spaced evenly in order to simulate a curved line. It is important to realize that the computer draws only straight lines and the curvature of map lines must be simulated by the use of small segments of straight lines. The number of points used to represent map lines is the result of a subjective decision, although to simulate curved lines, the use of a large number of points will result in a more accurate line than one that is simulated by only a few points. The starting point in a polygon sequence may be selected arbitrarily but the ending point must be identical to the starting point, so that the polygon is closed. Therefore, the starting coordinate pair will always be the same as the ending pair, and the number of coordinate pairs for any polygon will be one more than the actual number of points that have been defined for that polygon (because one pair is listed twice). Each set of coordinate pairs that comprise a polygon must be preceeded by a HEADER line of information that contains: 1. a 3-character (or number) polygon identifier 2. a separating COMMA 3. the number of coordinate pairs that comprise the polygon The following is an example of a simple 2-polygon data set: Bak , 5 The order of polygon coordinate SETS is 2.0 1.0 unimportant, as long as the same sequence is 4.0 1.0 used in the Statistical and Centroid (if any) 4.0 4.0 data sets. For counties, an alphabetical order 1.0 4.0 is useful, and a numerical order can be used 2.0 1.0 for units such as census tracts. Mar , 7 4.5 3.0 Note that the header lines contain the polygon 6.5 3.0 identifier (Bak for Baker, Mar for Marion), a 6.5 4.5 comma, and the # of coordinate pairs that follow. 6.0 5.0 5.5 6.0 The first coordinate is the X coordinate and 4.0 5.0 the second is the Y coordinate. Note also that 4.5 3.0 the first coordinate pair is identical to the last one, thus closing the polygon. There is no limit to the number of coordinate pairs that comprise any polygon, although there may be no more than 65 polygons. Neighboring polygons (map areas) contain identical coordinates along common boundaries because each polygon must be a separate, closed, coordinate set. Polygons do not have to be connected to each other. Although the creation of a polygon data set can be tedious, once it is established, it can serve as a base map for an infinite number of statistical displays, thus justifying the effort or expense. ----------------------------------------------------------------------- A-2 Format of Statistical Data Sets Statistical data sets are comprised of a sequence of lines, each containing a value that corresponds to a particular polygon. The order of values MUST be identical to the order of polygons in the polygon data set. If a map has 15 polygons (counties, etc.), then a statistical data set for that map should contain 15 statistical values, in the appropriate order. Of course, for each polygon data set, there may be an infinite number of statistical data sets, although only one is used per map. ------------------------------------------------------------------------ A-3 Format of Centroid Data Sets Section 1-4 discusses the need or preference for a separate centroid data set (instead of having the program calculate the centroids). Centroid data sets consist of X,Y coordinate pairs, one for each map unit, or polygon. Aside from being located INSIDE the boundary of each polygon, the location of centroids is a subjective decision made by the person who does the digitizing. Choropleth maps require only that the centroids be located within polygon boundaries, and the more important issue is that of where circles would be best located. This could be in a particularly "open" part of the polygon, although not necessarily in the middle. A data set of such locations would be acceptable for Choropleth maps and ideal for Circle maps. Remember, for a 15 unit polygon data set, an appropriate Centroid data set would contain 15 lines, each having 1 coordinate pair. Only the polygon data set contains more lines than there are polygons. ------------------------------------------------------------------------ A-4 Creation of Data Sets All data sets required by MapMaker are simply sequential lines of either coordinate pairs or statistical values. Any line editor or word- processing routine may be used to create and store such data sets. The EDLIN line editor provided with IBM/DOS can be used to create and modify data sets. A newly-created polygon data set would probably require editing because it is difficult to digitize and key such a large set of numbers without errors. NOTE: ** Arrangements may be made with the program's author to create and test customized polygon data sets. ** The author will pay $25.00 for the donation of any new and useful polygon data set. (data set must be of potential interest to others) ** Registered users may receive, free of charge, copies of new data sets existing in author's library. ----------------------------------------------------------------------- APPENDIX B. SAMPLE DATA SETS The following is a list of sample data sets that are provided with MapMaker for purposes of demonstration. Complete descriptions are given so that each may be used properly. (Appendix A describes the format of all data sets used with MapMaker.) B-1 Sample Data Sets Polygon Data Sets Descriptions ---------------- ------------------------------- flapan ------------ N.W. Florida (by counties, alphabetically) - 16 polygons - UPPER LEFT digitizer origin - digitized in INCHES - scale 1 : 950,000 **** - SEPARATE centroid file needed (fla-cent) gnv ------------ Gainesville, Florida (by C.Tracts, numerically) - 17 polygons - UPPER LEFT digitizer origin - digitized in INCHES - scale 1 : 4,000 - NO separate centroid file needed (calculate) offices ------------ Sample floor plan (by offices, numerically) - 34 polygons - LOWER LEFT digitizer origin - scale and unit not needed (derived values NOT needed-not geog.area) usa ------------ Contiguous U.S. (by states, alphabetically) - 48 polygons - LOWER LEFT digitizer origin - digitized in INCHES - scale 1 : 10,000,000 **** - SEPARATE centroid file needed (usa-cent) --------------------------------------------------------------------- Statistical Data Description ---------------- ------------------------------------------------- fla-pop (flapan) # of residents in each county in 1970 (raw) fla-inc (flapan) per capita income (dollars) in 1975 (derived) off-yrs (offices) # years of occupancy by present occupant gnv-65 (gnv) % of residents 65 yrs and older in 1970 (derived) gnv-pop (gnv) # of residents in 1970 (raw) usa-sun (usa) Percent sunny days during an ave. year (derived) usa-msa (usa) Percentage of Population Living in Urban Areas in 1980 (derived) ------------------------------------------------------------------------ Centroid Data Sets Corresponding Polygon Data ------------------ ----------------------------- fla-cent flapan usa-cent usa ----------------------------------------------------------------------- B-2 Screen Files A few files of saved screen images are provided so that examples of previously created maps may be seen. The screen files may be accessed by going through routine #3 from the main menu. When prompted for the name of a saved screen file, enter one of the following, with the appropriate drive designation, if necessary: Screen1 (Choropleth - Office Residency) Screen2 (Circle - Gainesville Population) Screen3 (Circle - N.W. Florida Population) Screen4 (Choropleth - Gainesville Elderly) Screen5 (Choropleth - U.S. Sunny Days) ----------------------------------------------------------------------- ----------------------------------------------------------------------- APPENDIX C. COMMENTS AND SUGGESTIONS MapMaker does not offer many opportunities for respecifying map elements during the create process. Even with the best conceived plan and careful specification, resulting maps usually require some alteration that is not apparent until the map is produced. Users are encouraged to continue the create process, even though a directive may not have been specified perfectly. Most errors can be corrected by using sub-menu modifications. - Make a backup copy of the MapMaker diskette. The DISKCOPY function provided with DOS can do this easily. - MapMaker was written in BASIC and is presented in compiled form. In addition to allowing the program to run faster, this protects the code. - MapMaker and its sample data sets fill up much of one diskette. Additional diskettes will be needed to store new data sets, including saved screen files. Always make a backup copy of important data sets. - To print maps on a matrix printer, it is necessary to initialize GRAPHICS while in DOS (BEFORE running program). See section 2-15. **Be sure to respecify color sequence when printing Choropleth maps. - The program may be interrupted at any time by pressing the CTRL and BREAK keys simultaneously. - For EXTREMELY small-scale polygon data sets, such as the "usa" data set, it may be preferable to enter pre-derived statistical values for Choropleth mapping. The area calculating routine within MapMaker will exaggerate digitizing imperfections, and thus yield imperfectly derived statistics. - If messages such as "Division by zero", or "Overflow" appear during program execution, there is probably an error in one or more of the data sets. Check the polygon data set for unclosed polygons and/or incorrect number of coordinates specified in headers. Check other data sets for proper number of data lines. - For purposes of convenience, system files (from DOS) may be added to the diskette containing MapMaker. - Slides taken from the color monitor can be very effective for presentation purposes. Camera lenses with relatively long focal lengths (135mm or longer) tend to reduce the curvature of the screen. Shutter speeds faster than 1/8 of a second should NOT be used. The following is a reference exposure setting: 250mm lens, 200ISO film, f/8 at 1 second Be sure to eliminate any room lighting in order to avoid reflection by the screen. Always bracket exposures. -----------------------------------------------------------------------