how to convert a waveform in 2D matrix?

i want to generate triangular fringe pattern without using meshgrid function i have a code for triangular wave and i want to convert it into fringe pattern 2D matrix.

%triangular wave form
t=0:1/100:1;
f=5;
I3=asin(sin(2*pi*f*t));
plot(I3)

Answer 1

[KSSV]

YOu can use repmat

%triangular wave form
t=0:1/100:1;
f=5;
I3=asin(sin(2*pi*f*t));
plot(I3)

N = 101 ;
iwant = repmat(I3,N,1) ;
pcolor(iwant)
shading interp

[ajeet verma]

all right but i want to create matrix using for loop for example

% sinusoidal fringe fringe
m=1000;
n=1000;
f1=20;  % No. of vertical fringes
f2=0;  % No. of horizontal fringes
for i=1:m
    for j=1:n
        a(i,j)=exp(1i*(2*pi*(f1*j/n+f2*i/m)));
    end
end
imshow(a,[])

this is sinusoidal fringe pattern and i want to create triangular as i asked