MATLAB: Creat a highway with driving cars’+’ and a police’>`on it.

random walkstreet line

The cars should drive with a rand speed on three lines i don't know how to make them move.

Best Answer

Use a loop. Inside the loop, call plot(), drawnow, and pause:

for k = 1 : numIterations
    % Determine coordinates for cars and police.  You do this, not me.
    % Now plot them all.
    cla;
    plot(xCars, yCars, 'b+', 'MarkerSize', 20, 'LineWidth', 2);
    hold on;
    plot(xPolice, yPolice, 'r>', 'MarkerSize', 20, 'LineWidth', 2);
    drawnow;
    pause(0.3); % Pause long enough to see this iteration.
end

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MATLAB: How to add to index in for loop

xc = zeros(numPanels, 1);
yc = zeros(numPanels, 1);
for k = 1:numPanels-1
      xc(k) = (xp(k) + xp(k+1))/2
      yc(k) = (yp(k) + yp(k+1))/2
  end

You are in MATLAB..you can avoid loops here.

xc = (xp(1:end-1)+xp(2:end))/2 ;
yc = (yp(1:end-1)+yp(2:end))/2 ;

But the problem is size of xc and yc will be one less then xp and yp.

MATLAB: Adding a legend manually for a plot generated by a loop

I think the issue is that you don't want to generate the plot like that; it's slow and makes it hard to label. Check out this solution instead:

 Y = 10*rand(100,1); %your data
 Ind = rand(100,1) > 0.5;
 Ind = Ind + (rand(100,1) > 0.75);
 Ind = Ind + 1; %an index corresponding to the group/colour of Y
 Vals = [1:100]'; %the X-axis, or location of Y
 plot(Vals(Ind == 1),Y(Ind ==1), 'ro', Vals(Ind == 2), ...
 Y(Ind == 2), 'bo', Vals(Ind == 3), Y(Ind == 3), 'go')
 legend('Red Data', 'Blue Data', 'Green Data')

This is much more efficient and you don't have to loop over all your points.

So, in your example, you would just go:

 i = [1:size(Ind,1)];
 plot(i(Ind == 1),Y(Ind ==1), 'ro', i(Ind == 2), ...
 Y(Ind == 2), 'bo', i(Ind == 3), Y(Ind == 3), 'go')
 legend('Red Data', 'Blue Data', 'Green Data')

Best Answer

Related Solutions

MATLAB: How to add to index in for loop

MATLAB: Adding a legend manually for a plot generated by a loop

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