peaks_fwhm {alkahest} | R Documentation |

## Half-Width at Half-Maximum

### Description

Estimates the Half-Width at Half-Maximum (FWHM) for a given peak.

### Usage

```
peaks_fwhm(x, y, ...)
## S4 method for signature 'numeric,numeric'
peaks_fwhm(x, y, center)
## S4 method for signature 'ANY,missing'
peaks_fwhm(x, center)
```

### Arguments

`x` , `y` |
A |

`...` |
Currently not used. |

`center` |
A |

### Details

It tries to get the smallest possible estimate.

### Value

A `numeric`

value.

### Author(s)

N. Frerebeau

### See Also

Other peaks detection methods:
`peaks_find()`

### Examples

```
## X-ray diffraction
data("XRD")
## 4S Peak Filling baseline
baseline <- baseline_peakfilling(XRD, n = 10, m = 5, by = 10, sparse = TRUE)
plot(XRD, type = "l", xlab = expression(2*theta), ylab = "Count")
lines(baseline, type = "l", col = "red")
## Correct baseline
XRD <- signal_drift(XRD, lag = baseline, subtract = TRUE)
## Find peaks
peaks <- peaks_find(XRD, SNR = 3, m = 11)
plot(XRD, type = "l", xlab = expression(2*theta), ylab = "Count")
lines(peaks, type = "p", pch = 16, col = "red")
abline(h = attr(peaks, "noise"), lty = 2) # noise threshold
## Half-Width at Half-Maximum
x <- seq(-4, 4, length = 1000)
y <- dnorm(x)
peaks_fwhm(x, y, center = 0) # Expected: 2 * sqrt(2 * log(2))
```

[Package

*alkahest*version 1.1.1 Index]