# How do you draw a circle on a picture in Matlab?

## How do you draw a circle on a picture in Matlab?

Draw a circular ROI on the image, Use the ‘Center’ name-value pair to specify the location of the circle and the ‘Radius’ name-value pair to specify its size. Set the edge of the circle to be striped by specifying the ‘StripeColor’ name-value pair. h = drawcircle(‘Center’,[1000,1000],’Radius’,500,’StripeColor’,’red’);

### How do you make a circle in Matlab?

How to create a filled circle?

1. function circles = circle(x,y,r)
2. hold on.
3. th = 0:pi/50:2*pi;
4. x_circle = r * cos(th) + x;
5. y_circle = r * sin(th) + y;
6. circles = plot(x_circle, y_circle);
7. hold off.

Is there a circle function in Matlab?

Description. viscircles( centers , radii ) draws circles with specified centers and radii onto the current axes. viscircles( ax , centers , radii ) draws circles onto the axes specified by ax .

How do you make a circle matrix in Matlab?

How to create a circle within a matrix

1. cx1 = .01; %x position of circle.
2. cy1 = .05; %y position of circle.
3. cr1 = .02; %radius of circle.
4. th = 0:pi/100:2*pi;
5. xunit = cr1 * cos(th) + cx1.
6. yunit = cr1 * sin(th) + cy1.
7. plot (xunit,yunit)

## How do you draw a polygon on a picture in Matlab?

roi = drawpolygon creates a Polygon object and enables interactive drawing of a polygonal ROI on the current axes. To draw the ROI, position the pointer on the image. The cursor changes to a fleur shape. Click to draw vertices of the polygon and drag to draw the lines between the vertices.

### How do you create a mask in Matlab?

1. Step 1: Open Mask Editor. Open the model in which you want to mask a block.
2. Step 2: Define the Mask. The Mask Editor contains four tabs that enable you to define the block mask and customize the dialog box for the mask.
3. Step 3: Operate on Mask.

How do you plot a circle?

Graphing circles centered away from the origin

1. Locate the center of the circle from the equation (h, v).
2. Calculate the radius by solving for r.
3. Plot the radius points on the coordinate plane.
4. Connect the dots to the graph of the circle with a round, smooth curve.

How do you draw a half circle in Matlab?

1. xCenter_2 = 3/(2*sqrt(13));
2. yCenter_2 = -1/sqrt(13);
3. theta = 0-2/3 : 0.01 : pi-2/3;
5. x = radius * cos(theta) + xCenter_2;
6. y = radius * sin(theta) + yCenter_2;
7. plot(x, y), hold on;
8. axis square;

## How do you graph a circle equation?

Explanation: The equation of a circle is \displaystyle (x – h)^2 + (y – k)^2 = r^2, in which (h, k) is the center of the circle and r is its radius. Because the graph of the circle is centered at (0, 0), h and k are both 0. Because the radius is 3, the right side of the equation is equal to 9.

### How do I mask an image in MATLAB?

1. To create a mask like you said: Theme. maxGL = max(grayImage(:))
2. To apply the mask to an RGB image, use this code: Theme. % Mask the image using bsxfun() function to multiply the mask by each channel individually.
3. If it’s grayscale, you can do it simpler like this: Theme. grayImage(~mask) = 0;

How do you put a mask on a picture?