Sound File: creating left and right channels

I am new to matlab and was wondering if this is the correct way to specific left and right channels for a simple sound file I created and am trying to play (or if there is a better/simpler way):

x = [0:.1:1000*pi];      
u = [0:.1:500*pi];      
v = [501*pi:.1:1000*pi]; 

sinseg1 = sin(u);        
sinseg2 = sin(v);        
sinseg1_stereo = [sinseg1 * .2, sinseg1 * .8]; 
sinseg2_stereo = [sinseg2 * .8, sinseg2 * .2]; 

sound(sinseg1,1000);                           
sound(sinseg2,1000);

Answer 1

[Walter Roberson]

dual_channel = [sinseg1_stereo(:), sinseg2_stereo(:)];
sound(dual_channel, 1000);

But I have to ask you what your intention was for

[sinseg1 * .2, sinseg1 * .8]

If I were to guess, I suspect what you wanted was

sinseg1_stereo = sinseg1 .* 0.2 + sinseg2 .* 0.8;

[Walter Roberson]

Okay, I will take another guess then:

sinseg1_stereo = [sinseg1(:) * .2, sinseg1(:) * .8]; 
sinseg2_stereo = [sinseg2(:) * .8, sinseg2(:) * .2]; 

sound(sinseg1_stereo,1000);                           
sound(sinseg2_stereo,1000);

Answer 2

[Cyrus]

This is based on a tutorial I watched ( http://www.youtube.com/watch?v=ie7iREcYBPU, 18th minute approx.). I think sinseg1_stereo = sinseg1 .* 0.2 sinseg .* 0.8; is closer but I don't think addition is needed should I use a comma?