# logit
> Compute the [logit][logit] function.
The [logit][logit] function is defined as the logarithm of the odds `p / (1-p)`; i.e.,
The [logit][logit] function is the inverse of the [standard logistic][standard-logistic] function, sometimes also called the sigmoid function.
## Usage
```javascript
var logit = require( '@stdlib/math/base/special/logit' );
```
#### logit( p )
Computes the [logit][logit] function.
```javascript
var v = logit( 0.2 );
// returns ~-1.386
v = logit( 0.9 );
// returns ~2.197
```
If `p < 0` or `p > 1`, the function returns `NaN`.
```javascript
var v = logit( 1.3 );
// returns NaN
v = logit( -0.2 );
// returns NaN
```
## Examples
```javascript
var randu = require( '@stdlib/random/base/randu' );
var logit = require( '@stdlib/math/base/special/logit' );
var p;
var i;
for ( i = 0; i < 100; i++ ) {
p = randu();
console.log( 'logit(%d) = %d', p, logit( p ) );
}
```
[logit]: https://en.wikipedia.org/wiki/Logit
[standard-logistic]: https://en.wikipedia.org/wiki/Logistic_function
