make gridlines and enter the x and y coordinates of an object to change its position on the page.

Hi, I have an image that I need to trace and know the position of its x-y coordinates.

So far I have been able to trace and get the x-y coordinate information from the results of the traced image. But after the coordinates came out, the location of the point was not what I wanted.

Is there a way to enter the x -y values to change its position? And maybe I was wondering if there is a way to make gridlines so its easier when i trace the image.

Thank you!

[KSSV]

You can plot the grid lines using given points using plot. Won't this work?

[Grishelda Athallah]

im sorry sir, i dont quite understand what your point is. What do you mean using plot?

Answer 1

[Image Analyst]

You can overlay gridlines on the image with xline() and yline()

[rows, columns, numColors] = size(rgbImage)
for row = 1 : 20 : rows
    yline(row, 'Color', 'r', 'LineWidth', 2);
end
for col = 1 : 20 : columns
    xline(col, 'Color', 'r', 'LineWidth', 2);
end

If you want to edit/change the x and y values you can do that by double clicking the array in the workspace panel to bring it up in the Variable Editor, then you can just type in the values you want. Or of course you can just do it from the command line if you want:

x(9) = 100; % Change point #9
y(9) = 800;

or whatever.

[Grishelda Athallah]

Undefined function or variable 'yline'.

Error in TRACEMASK (line 10)

yline(row, 'Color', 'r', 'LineWidth', 2);

i've tried but error, what does it mean?

[Image Analyst]

You must have an old version of MATLAB. You blew right past that part when you originally posted where it asked you for your version number for some reason. Why did you not fill out the entire form when you posted?

Anyway, you can replace yline with this:

[rows, columns, numColors] = size(rgbImage)
hold on;
for row = 1 : 20 : rows
    plot([1, columns], [row, row], 'Color', 'r', 'LineWidth', 2);
end
for col = 1 : 20 : columns
    plot([col, col], [1, rows], 'Color', 'r', 'LineWidth', 2);
end
hold off;