polybl.sml

## POLYBL.SML

## This sample script illustrates the use of some of the
## vector and database functions in SML. It is designed to operate
## on a vector object containing contiguous polygons that might
## represent countries, states, counties, census blocks, etc.  The script
## selects four specific polygons by attribute, and computes
## the total length of the polygon boundary lines that are not
## shared between the selected polygons.  For a block of contiguous 
## polgyons, this is the perimeter of the block. If none of the
## selected polygons are contiguous, the calculated length 
## is the total boundary length of the selected polygons.

## The checks for the class of adjacent polygons require explicit 
## database table.field references which must be provided for the
## the particular vector object being used.  This example uses the
## vector object 'states' in the UNTDSTAT.RVC Project File in the
## USA sample data collection. 

## Polygons are selected by the name of the state, which is contained
## in the STATE_NAME field in the 'states' database table.
## The line list for a selected polygon is accessed, and database
## references are used to check the class assignments for the polygons
## on either side of each line.  If either polygon is not among the
## selected set of states, the line length is added to a perimeter
## variable for the polygon. 

## For each selected polygon, the SML script outputs the following
## data for each unshared boundary line: line element number, 
## the state to the left and right sides, and the line length.
## The summed unshared boundary length is then reported for the polygon.
## When all selected polygons have been processed, the total unshared
## boundary length for the selected set is reported.  The in-depth
## report facilitates checking that the polygon adjacency selection
## criteria are working correctly.

## Output information is printed to the console window, and written
## to a text file.

## AUTHOR: Randy Smith, MicroImages, Inc.
## CREATION DATE: May 13, 1997


clear();
class VECTOR V;
class FILE output;
GetInputVector(V);

# Set up PopUp Dialogs to provide names of states
string s1$, s2$, s3$, s4$;
s1$ = PopupString("Enter the name of the first state with first letter capitalized: ", "Nebraska");
s2$ = PopupString("Enter the name of the second state: ", "Kansas");
s3$ = PopupString("Enter the name of the third state: ", "Colorado");
s4$ = PopupString("Enter the name of the fourth state: ", "Wyoming");

# Set up PopUp Dialog to name an output text file for results
string defaultfile$ = "c:/DATA/boundout.txt";
$ifdef _MI_INTERNAL_AUTOTEST_MODE
	defaultfile$ = CreateTempFileName();
$endif
string outfile$ = PopupString( "Enter path and filename for results text file:", defaultfile$ );
output = fopen(outfile$, "a+");

# Initialize perimeter variables
numeric perim1, perim2, perim3, perim4, tperim;
perim1 = 0;	# unshared perimeter of state1
perim2 = 0;	# unshared perimeter of state2
perim3 = 0;	# unshared perimeter of state3
perim4 = 0;	# unshared perimeter of state4
tperim = 0;	# total unshared perimeter of selected states

# Define array to contain list of line numbers for the selected polygon.
# Array size is arbitrary; it will be resized automatically by 
# the GetVectorPolyLinelist function.
array numeric linelist[10];

# Main processing loop
numeric i;
numeric numlines, linenum;
numeric leftpoly, rightpoly;
numeric len1, len2, len3, len4;
for each poly in V begin
	if (V.poly.states.STATE_NAME$ == s1$ ) then begin		# processing loop for state1
		printf( "\n\n--------------\n%s", s1$ );				# print separator line in console window
		fprintf( output, "\n\n------------\n%s", s1$ );		# print separator line in output file 

	   numlines = GetVectorPolyLineList(V, linelist);		# get list of lines and assign number
																			# of lines to variable

		for i = 1 to numlines begin
			linenum = linelist[i];
			leftpoly = V.line[linenum].Internal.LeftPoly;		# get number of polygon to left
			rightpoly = V.line[linenum].Internal.RightPoly;		# get number of polygon to right
			if ( ( V.poly[leftpoly].states.STATE_NAME$ == s1$ and
				! ( V.poly[rightpoly].states.STATE_NAME$ == s2$ or		# database query to select
				V.poly[rightpoly].states.STATE_NAME$ == s3$ or			# lines not shared with
				V.poly[rightpoly].states.STATE_NAME$ == s4$ ) )			# other selected states
				or
				( V.poly[rightpoly].states.STATE_NAME$ == s1$ and
				! ( V.poly[leftpoly].states.STATE_NAME$ == s2$ or
				V.poly[leftpoly].states.STATE_NAME$ == s3$ or
				V.poly[leftpoly].states.STATE_NAME$ == s4$ ) )  ) then begin

				len1 = V.line[linenum].LINESTATS.Length;		# get line length from LINESTATS
				printf( "\n\nLine: %d\tLength: %10.3f", linenum, len1 );
				fprintf( output, "\n\nLine: %d\tLength: %10.3f", linenum, len1 ); 
				printf( "\nLeftPoly = %s\t\tRightPoly = %s", V.poly[leftpoly].states.STATE_NAME$, 
									V.poly[rightpoly].states.STATE_NAME$ );
				fprintf( output, "\nLeftPoly = %s\t\tRightPoly = %s", V.poly[leftpoly].states.STATE_NAME$,
									V.poly[rightpoly].states.STATE_NAME$ );
				perim1 = perim1 + len1;								# add length of line to perim
			end
		end
		printf( "\n\nUnshared boundary length of %s = %10.3f meters", s1$, perim1 );
		fprintf( output, "\n\nUnshared boundary length of %s = %10.3f meters", s1$, perim1 );
	end

	if (V.poly.states.STATE_NAME$ == s2$ ) then begin		# processing loop for state2
		printf( "\n\n--------------\n%s", s2$ );
		fprintf( output, "\n\n----------------\n%s", s2$ );

	   numlines = GetVectorPolyLineList(V, linelist);

		for i = 1 to numlines begin
			linenum = linelist[i];
			leftpoly = V.line[linenum].Internal.LeftPoly;
			rightpoly = V.line[linenum].Internal.RightPoly;
			if ( ( V.poly[leftpoly].states.STATE_NAME$ == s2$ and
				! ( V.poly[rightpoly].states.STATE_NAME$ == s1$ or
				V.poly[rightpoly].states.STATE_NAME$ == s3$ or
				V.poly[rightpoly].states.STATE_NAME$ == s4$ ) )
				or
				( V.poly[rightpoly].states.STATE_NAME$ == s2$ and
				! ( V.poly[leftpoly].states.STATE_NAME$ == s1$ or
				V.poly[leftpoly].states.STATE_NAME$ == s3$ or
				V.poly[leftpoly].states.STATE_NAME$ == s4$ ) )  ) then begin

				len2 = V.line[linenum].LINESTATS.Length;
				printf( "\n\nLine: %d\tLength: %10.3f", linenum, len2 );
				fprintf( output, "\n\nLine: %d\tLength: %10.3f", linenum, len2 );
				printf( "\nLeftPoly = %s\t\tRightPoly = %s", V.poly[leftpoly].states.STATE_NAME$, 
									V.poly[rightpoly].states.STATE_NAME$ );
				fprintf( output, "\nLeftPoly = %s\t\tRightPoly = %s", V.poly[leftpoly].states.STATE_NAME$,
									V.poly[rightpoly].states.STATE_NAME$ );
				perim2 = perim2 + len2;
			end
		end
		printf( "\n\nUnshared boundary length of %s = %10.3f meters", s2$, perim2 );
		fprintf( output, "\n\nUnshared boundary length of %s = %10.3f meters", s2$, perim2 );
	end

	if (V.poly.states.STATE_NAME$ == s3$ ) then begin		# processing loop for state3
		printf( "\n\n--------------\n%s", s3$ );
		fprintf( output, "\n\n--------------\n%s", s3$ ); 

	   numlines = GetVectorPolyLineList(V, linelist);

		for i = 1 to numlines begin
			linenum = linelist[i];
			leftpoly = V.line[linenum].Internal.LeftPoly;
			rightpoly = V.line[linenum].Internal.RightPoly;
			if ( ( V.poly[leftpoly].states.STATE_NAME$ == s3$ and
				! ( V.poly[rightpoly].states.STATE_NAME$ == s1$ or
				V.poly[rightpoly].states.STATE_NAME$ == s2$ or
				V.poly[rightpoly].states.STATE_NAME$ == s4$ ) )
				or
				( V.poly[rightpoly].states.STATE_NAME$ == s3$ and
				! ( V.poly[leftpoly].states.STATE_NAME$ == s1$ or
				V.poly[leftpoly].states.STATE_NAME$ == s2$ or
				V.poly[leftpoly].states.STATE_NAME$ == s4$ ) )  ) then begin

				len3 = V.line[linenum].LINESTATS.Length;
				printf( "\n\nLine: %d\tLength: %10.3f", linenum, len3 ); 
				fprintf( output, "\n\nLine: %d\tLength: %10.3f", linenum, len3 );
				printf( "\nLeftPoly = %s\t\tRightPoly = %s", V.poly[leftpoly].states.STATE_NAME$, 
									V.poly[rightpoly].states.STATE_NAME$ );
				fprintf( output, "\nLeftPoly = %s\t\tRightPoly = %s", V.poly[leftpoly].states.STATE_NAME$,
									V.poly[rightpoly].states.STATE_NAME$ );
				perim3 = perim3 + len3;
			end
		end
		printf( "\n\nUnshared boundary length of %s = %10.3f meters", s3$, perim3 );
		fprintf( output, "\n\nUnshared boundary length of %s = %10.3f meters", s3$, perim3 );
	end

	if (V.poly.states.STATE_NAME$ == s4$ ) then begin		# processing loop for state4
		printf( "\n\n--------------\n%s", s4$ );
		fprintf( output, "\n\n-----------------\n%s", s4$ );

	   numlines = GetVectorPolyLineList(V, linelist);

		for i = 1 to numlines begin
			linenum = linelist[i];
			leftpoly = V.line[linenum].Internal.LeftPoly;
			rightpoly = V.line[linenum].Internal.RightPoly;
			if ( ( V.poly[leftpoly].states.STATE_NAME$ == s4$ and
				! ( V.poly[rightpoly].states.STATE_NAME$ == s1$ or
				V.poly[rightpoly].states.STATE_NAME$ == s2$ or
				V.poly[rightpoly].states.STATE_NAME$ == s3$ ) )
				or
				( V.poly[rightpoly].states.STATE_NAME$ == s4$ and
				! ( V.poly[leftpoly].states.STATE_NAME$ == s1$ or
				V.poly[leftpoly].states.STATE_NAME$ == s2$ or
				V.poly[leftpoly].states.STATE_NAME$ == s3$ ) )  ) then begin

				len4 = V.line[linenum].LINESTATS.Length;
				printf( "\n\nLine: %d\tLength: %10.3f", linenum, len4 );
				fprintf( output, "\n\nLine: %d\tLength: %10.3f", linenum, len4 );
				printf( "\nLeftPoly = %s\t\tRightPoly = %s", V.poly[leftpoly].states.STATE_NAME$, 
									V.poly[rightpoly].states.STATE_NAME$ );
				fprintf( output, "\nLeftPoly = %s\t\tRightPoly = %s", V.poly[leftpoly].states.STATE_NAME$,
									V.poly[rightpoly].states.STATE_NAME$ );
				perim4 = perim4 + len4;
			end
		end
		printf( "\n\nUnshared boundary length of %s = %10.3f meters", s4$, perim4 );
		fprintf( output, "\n\nUnshared boundary length of %s = %10.3f meters", s4$, perim4 );
	end
end

tperim = perim1 + perim2 + perim3 + perim4;			# calculate total unshared perimeter
 
printf( "\n\n=====================\n\nTotal unshared boundary length of states = %10.5f meters", tperim );
fprintf( output, "\n\n=================\n\nTotal unshared boundary length of states = %10.5f meters", tperim );

fclose(output);