Now my question what should I add in that code to make the code display 0 on the values less than 0 because now with my code it goes down to the negative values.Thank you.

My unit ramp function was r[n] = 0 when n<0 and n when 4=<n>=9. I had to code and display the results of this Ramp function. And this was my code.

n=(-20:1:20)';
ramp_n((n<=4).*n+(n>=9).*n);

Unrecognized function or variable 'ramp_n'.

stem(n,ramp_n);

Answer 1

[Walter Roberson]

You should be multiplying logical conditions, not adding them.

[khumbula higa]

I tried that and my code was like below and they all become zeros now ,even the ones that were supposed to form a remp.

n=(-20:1:20)';
ramp_n=((n<=4).*n.*(n>=9)).*n);
stem(n,ramp_n);

[Walter Roberson]

1. Remember that multiplication is commutative, so what you have coded there is equivalent to (n<=4).*(n>=9).*(n.*n) which is obviously not correct, as it would output either 0 or n^2 rather than 0 or n . You should only have had one multiplication by n
2. You want n between 4 and 9, but (n<=4) is true (1) when n is less than 4 -- a condition in which you want 0 to be output, not 1. You need your condition to be true (1) when n is inside the desired range, not when it is outside the desired range. (4<= n & n <= 9)

n = (-20:1:20)';
ramp_n = (4<=n).*(n<=9).*n;
stem(n, ramp_n);