linspace

Generate linearly spaced vectors
Syntax
y = linspace(a,b)
y = linspace(a,b,n)
Description
The linspace function generates linearly spaced vectors. It is similar to the colon operator ":", but gives direct control over the number of points.
y = linspace(a,b) generates a row vector y of 100 points linearly spaced between and including a and b.
y = linspace(a,b,n) generates a row vector y of n points linearly spaced between and including a and b.

logspace

Generate logarithmically spaced vectors
Syntax
y = logspace(a,b)
y = logspace(a,b,n)
y = logspace(a,pi)
Description
The logspace function generates logarithmically spaced vectors. Especially useful for creating frequency vectors, it is a logarithmic equivalent of linspace and the ":" or colon operator.

y = logspace(a,b)

• generates a row vector y of 50 logarithmically spaced points between decades 10^a and 10^b.

y = logspace(a,b,n)

• generates n points between decades 10^a and 10^b.

y = logspace(a,pi)

• generates the points between 10^a and pi, which is useful for digital signal processing where frequencies over this interval go around the unit circle.
• Remarks
  All the arguments to logspace must be scalars