logspace

Generate logarithmically spaced vector

Syntax

• ``y = logspace(a,b)``
example
• ``y = logspace(a,b,n)``
example
• ``y = logspace(a,pi)``

Description

example

````y = logspace(a,b)` generates a row vector `y` of 50 logarithmically spaced points between decades `10^a` and `10^b`. The `logspace` function is especially useful for creating frequency vectors. The function is the logarithmic equivalent of `linspace` and the ‘`:`' operator.```

example

````y = logspace(a,b,n)` generates `n` points between decades `10^a` and `10^b`.```
````y = logspace(a,pi)` generates points between `10^a` and `pi`, which is useful in digital signal processing for creating logarithmically spaced frequencies in the interval `[10^a,pi]`.```

Examples

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Vector of Logarithmically Spaced Numbers

Create a vector of 50 logarithmically spaced points in the interval `[10^1,10^5].`

```y = logspace(1,5); ```

Vector with Specified Number of Values

Create a vector of 7 logarithmically spaced points in the interval `[10^1,10^5].`

```y1 = logspace(1,5,7) ```
```y1 = 1.0e+05 * 0.0001 0.0005 0.0022 0.0100 0.0464 0.2154 1.0000 ```

Vector of Logarithmically Spaced Complex Numbers

Create a vector of complex numbers with 8 logarithmically spaced points between `10^(1+2i) and 10^(5+5i).`

```y = logspace(1+2i,5+5i,8) ```
```y = 1.0e+04 * Columns 1 through 4 -0.0001 - 0.0010i 0.0029 - 0.0024i 0.0133 + 0.0040i 0.0147 + 0.0497i Columns 5 through 8 -0.1242 + 0.1479i -0.7150 - 0.0822i -1.2137 - 2.3924i 4.9458 - 8.6913i ```

Input Arguments

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`a` — First boundnumeric scalar

First bound, specified as a numeric scalar. The `a` argument defines a bound of the interval over which `logspace` generates points. `a` can be real or complex, and the other bound, `b`, can be either larger or smaller than `a`. If `b` is smaller than `a`, then the vector contains descending values.

Data Types: `single` | `double`
Complex Number Support: Yes

`b` — Second boundnumeric scalar

Second bound, specified as a numeric scalar. The `b` argument defines a bound of the interval over which `logspace` generates points. `b` can be real or complex, and `b` can be either larger or smaller than the other bound, `a`. If `b` is smaller than `a`, then the vector contains descending values.

Data Types: `single` | `double`
Complex Number Support: Yes

`n` — Number of points50 (default) | real numeric scalar

Number of points, specified as a real numeric scalar.

• If `n` is `1`, `logspace` returns `10^b`.

• If `n` is zero or negative, `logspace` returns an empty row vector.

• If `n` is not an integer, `logspace` rounds `n` down and returns `floor(n)` points.