Making Triangle in matlab

How do I make the triangle without plotting function like that?

Answer 1

[KSSV]

m = 100;
n = 2*m;

I = zeros(m,n) ; 
for i = 1:m-1
  idx = (n/2-i):(n/2+i) ;
  I(i,idx)= 1 ;
end
imshow(I)

[Wahab Ahmad]

acutally i want this thing you work is good but when i want this nearest size of this triangle

[KSSV]

This is more simple buddy.....get the three vertices you want, use inpolygon and change the values.

Example:

m = 100 ; 
n = 100 ; 
[X,Y] = meshgrid(1:m,1:n) ; 

A = [47 77] ;
B = [25 35] ;
C = [25 70] ; 
P = [ A; B; C; A] ; 

idx = inpolygon(X,Y,P(:,1),P(:,2)) 

[Wahab Ahmad]

Thats the only code i have to run and get this figure

[Wahab Ahmad]

That code is not works

[KSSV]

Why it not work? You have to change vertices accordingly.

Answer 2

[Image Analyst]

You can use poly2mask

x = [100, 200, 300]; % Left vertex, top vertex, right vertex.
y = [300, 100, 300]; % Left vertex, top vertex, right vertex.
mask = poly2mask(x, y, 400, 400);
imshow(mask);
axis on