ABI {DFA} | R Documentation |

## Activity balance index (ABI)

### Description

This function estimates the Activity balance index (ABI), which is a transformation of the self-similarity parameter (SSP), also known as scaling exponent or alpha.

### Usage

```
ABI(x)
```

### Arguments

`x` |
the estimated self-similarity parameter (SSP) |

### Details

ABI = exp(-abs(SSP-1)/exp(-2))

### Value

The estimated Activity balance index (ABI) is a real number between zero and one.

### Author(s)

Ian Meneghel Danilevicz

### References

Danilevicz, I.M., van Hees, V.T., van der Heide, F., Jacob, L., LandrĂ©, B., Benadjaoud, M.A., Sabia, S. (2023). Measures of fragmentation of rest activity patterns: mathematical properties and interpretability based on accelerometer real life data. Research square. 10.21203/rs.3.rs-3543711/v1.

### Examples

```
# Estimate Activity balance index of a very known time series available on R base: the sunspot.year.
library(DFA)
alpha = SSP(sunspot.year, scale = 1.2)
abi = ABI(alpha)
```

[Package

*DFA*version 1.0.0 Index]