Calculate distance between 2 points (read)?

I was asked to write a simple program that reads the coordinates of 2 points and then calculates the distance between them.

I really don't know where to start im a complete rookie so a thorough explanation is appreciated.

Thank you!

Answer 1

[Image Analyst]

How about using imdistline() or improfile() if you have the Image Processing Toolbox.

See attached spatial calibration demo.

[Erwin Folkesang]

But how do you first create 2 points in the middle of nowhere and then use imdistline() to calculate the distance between them? (sorry for rookie question)

[Image Analyst]

This is for when you are displaying an image. You click on each end of the line. Click one end and get a rubber band line, then click on the other end. What kind of display are you wanting to click on????

Answer 2

[Star Strider]

You can use the hypot function, or write a version of your own:

x(1,:) = rand(2,1);
x(2,:) = rand(2,1)*10;
dx = diff(x,1)
d = hypot(dx(1), dx(2))

figure(1)
plot(x(1,1), x(1,2), 'pb')
hold on
plot(x(2,1), x(2,2), 'pb')
plot([x(1,1) x(2,1)], [x(1,2) x(2,2)], '-r')
hold off
text(x(1,1),x(1,2), sprintf('  (%.2f, %.2f)', x(1,:)), 'FontSize',8)
text(x(2,1),x(2,2), sprintf('  (%.2f, %.2f)', x(2,:)), 'FontSize',8)
mnx = mean(x,1);
text(mnx(1),mnx(2), sprintf('  Distance = %.2f',d), 'FontSize',8)
xlabel('x \rightarrow')
ylabel('y \rightarrow')
axis([xlim+[-.2  .2]    ylim+[-.2  .2]])
grid

EDIT: Added plot