# Basic feasible solution MATLAB changing size for any n * n input

hello, I am an Israeli student for ‏‎Information System Engineering‎‏, and I have a question in Matlab. I have to change this code in order to suit it for any size (any n*n). hope for full answers that actually change the code.

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %This code executes breadth first search. This simulation is meant to %mimick a robot navigating through a grid and planning a path around %obstacles. The user defines the obstacles, goal, and starting position. %This simulation is set up for a 5 x 5 grid that ranges from (0,0) to %(5,5). This code is written for Matlab 7.0. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% clear all close all clc %%% THIS IS WHERE THE OBSTACLES ARE DEFINED %%% % obstacles(1,:)=[2,4]; % obstacles(2,:)=[3,4]; % obstacles(3,:)=[4,2]; % obstacles(4,:)=[4,3]; % obstacles(5,:)=[4,4]; % obstacles(1,:)=[1,1]; % obstacles(2,:)=[1,2]; % obstacles(3,:)=[1,3]; % obstacles(4,:)=[2,1]; % obstacles(5,:)=[3,1]; obstacles(1,:)=[4,5]; obstacles(2,:)=[4,1]; obstacles(3,:)=[4,2]; obstacles(4,:)=[4,3]; obstacles(5,:)=[4,4]; %%% THIS IS WHERE THE STARTING POSITION %%% %%% AND GOAL LOCATION ARE DEFINED %%% startingPosition=[5,5]; goal=[0,5]; %Define the colors for plotting the results obstacleColor=[1,0,0]; %red nodeColor=[0,1,0]; %green expandColor=[0,0,0]; %black goalColor=[0,0,1]; %blue pathColor=[0,1,1]; %cyan %Plot the grid and obstacles scatter(obstacles(:,1),obstacles(:,2),100,obstacleColor,'filled'); grid ; axis([0 5 0 5]); hold on; %Plot the goal position scatter(goal(1,1),goal(1,2),100,goalColor,'filled'); %Initialize variables fringeCount=1; %Used for stepping through the fringe set (keeps track of the current node in the fringe set) tempCount=1; %Used for expanding the fringe set (keeps track of the end of the fringe set) %Initialize the fringe set. the structure is: %fringe(xPosition, yPosition, parentNode) fringe(fringeCount,:)=[startingPosition,fringeCount]; %This loop executes until the goal is found while (~((fringe(fringeCount,1)==goal(1,1)) & (fringe(fringeCount,2)==goal(1,2)))) %Plot the current node scatter(fringe(fringeCount,1),fringe(fringeCount,2),100,nodeColor,'filled'); %Expand the fringe set to the left, right, top and bottom of the current node for x=-1:1 for y=-1:1 %This is a simple test to ensure that the fringe set isn't %expanded diagonally as the robot can not move diagonally if (x*y==0) %'failsTest' is used to determine when a node can not be %expanded because it is outside the grid, on an obstacle, %or it has already been expanded. failsTest=0; %'tempNode' is the current node that is trying to be %expanded tempNode=[fringe(fringeCount,1)+x,fringe(fringeCount,2)+y, fringeCount]; %Test to see if the node is outside grid if ( (tempNode(1,1)<0) | (tempNode(1,2)<0) ) | ( (tempNode(1,1)>5) | (tempNode(1,2)>5) ) failsTest=failsTest+1; end %If it did not fail the first test, test to see if node is %already in fringe set. if (failsTest<1) for i=1:size(fringe,1) if (tempNode(1,1)==fringe(i,1)) & (tempNode(1,2)==fringe(i,2)) failsTest=failsTest+1; end end end %If it did not fail the other tests, test to see if node is %an obstacle if (failsTest<1) for i=1:size(obstacles,1) if (tempNode(1,1)==obstacles(i,1))&(tempNode(1,2)==obstacles(i,2)) failsTest=failsTest+1; end end end %If it doesn't fail any tests, add to end of fringe set. %In breadth first search, nodes are removed from the end of %the fring set, so to make things easy we add new nodes to %the end. if (failsTest<1) fringe(fringeCount+tempCount,:)=tempNode; scatter(tempNode(1,1),tempNode(1,2),100,expandColor,'filled'); tempCount=tempCount+1; end end end end %Increment to the next node. When you increment, you must also %decrement tempCount since it is defined as a position in the fringe %set relative to fringeCount fringeCount=fringeCount+1; tempCount=tempCount-1; pause(5); end %Initialize a counter i=1; %Trace back through the parent nodes to receover the path while ~(fringeCount==1) path(i,:)=[fringe(fringeCount,1),fringe(fringeCount,2)]; fringeCount=fringe(fringeCount,3); i=i+1; end %Add the start position to the path path(i,:)=startingPosition; %Plot the path plot(path(:,1),path(:,2)); scatter(path(:,1),path(:,2),100,pathColor,'filled');

asked Jan 12, 2016