why this message error ?:Array indices must be positive integers or logical values

Hi,

When i write this little script:

---------------------------------------------------------------------------------------------------------

demo matlab

 t = (10:1:200)';

 y = sin(2*pi*50*t)

z = y(t-10)

w = y+z

plot(t(1:50),w(1:50))

sound(w,Fs);

-------------------------------------------------------------------------------------------------------

there is a message error: message error: Array indices must be positive integers or logical values.

Howewer,when i write this:

-----------------------------------------------------------------------------------------------------

demo matlab

 t = (0:0.001:100)';

 y = sin(2*pi*50*t)

plot(t(1:50),y(1:50))

sound(y,Fs);

------------------------------------------------------------------------------------------------------

there is no message error.

Why?

thanks

Answer 1

[Image Analyst]

It's pretty well explained by the FAQ: http://matlab.wikia.com/wiki/FAQ#How_do_I_fix_the_error_.22Subscript_indices_must_either_be_real_positive_integers_or_logicals..22.3F

Answer 2

[jérôme TAÏEB]

Ok but

demo matlab

 t = (11:1:200)';

 y = sin(2*pi*50*t)

z = y(t-10)

w = y+z

plot(t(1:50),w(1:50))

sound(w,44000);

no longer presents an error message but no sound comes out!

Why ?

[Image Analyst]

Who are you talking to? This should be a comment to someone , not an answer to your original question.

Try soundsc().

[Star Strider]

The sound is there. It is of too short a duration to notice:

signal_duration = (200-11)/44000

signal_duration =
       0.00429545454545455

It only lasts for 4.3 milli-seconds!

[jérôme TAÏEB]

It doesn't work !

Can i have the completely corrected code?

Answer 3

[Image Analyst]

See attached sound making demo. It doesn't make your sound but adapt it as needed.