Peaks.jl

Peaks.argmaxima — Function

argmaxima(x[, w=1; strict=true])

Find the indices of the local maxima of x where each maxima i is either the maximum of x[i-w:i+w] or the first index of a plateau.

If strict is true, all elements of x[i-w:i+w] or the bounds of a plateau must exist and must not be missing or NaN. For strict == false, a maxima is the maximum or first element of all existing and non-NaN or missing elements in x[i-w:i+w] or the bounds of a plateau.

Examples

julia> argmaxima([0,2,0,1,1,0])
2-element Vector{Int64}:
 2
 4

julia> argmaxima([2,0,1,1])
Int64[]

julia> argmaxima([2,0,1,1]; strict=false)
2-element Vector{Int64}:
 1
 3

source

Peaks.argminima — Function

argminima(x[, w=1; strict=false])

Find the indices of the local minima of x where each minima i is either the minimum of x[i-w:i+w] or the first index of a plateau.

If strict is true, all elements of x[i-w:i+w] or the bounds of a plateau must exist and must not be missing or NaN. For strict == false, a minima is the minimum or first element of all existing and non-NaN or missing elements in x[i-w:i+w] or the bounds of a plateau.

Examples

julia> argminima([3,2,3,1,1,3])
2-element Vector{Int64}:
 2
 4

julia> argminima([2,3,1,1])
Int64[]

julia> argminima([2,3,1,1]; strict=false)
2-element Vector{Int64}:
 1
 3

source

Peaks.maxima — Function

maxima(x[, w=1; strict=true])

Find the values of the local maxima of x where each maxima i is either the maximum of x[i-w:i+w] or the first index of a plateau.

See also: findminima, findmaxima

Examples

julia> x = [0,5,2,3,3,1,4,0];

julia> xpks = argmaxima(x)
3-element Vector{Int64}:
 2
 4
 7

julia> peakproms(xpks, x)
([2, 4, 7], Union{Missing, Int64}[5, 1, 3])

julia> x = [missing,5,2,3,3,1,4,0];

julia> peakproms(xpks, x)
([2, 4, 7], Union{Missing, Int64}[missing, 1, 3])

julia> peakproms(xpks, x; strict=false)
([2, 4, 7], Union{Missing, Int64}[5, 1, 3])

source

Peaks.peakproms! — Function

peakproms!(peaks, x;
    strict=true,
    minprom=nothing,
    maxprom=nothing
) -> (peaks, proms)

Calculate the prominences of peaks in x, removing peaks with prominences less than minprom or greater than maxprom, if either are given. Returns the modified peaks and their prominences.

source

Peaks.peakwidths — Function

peakwidths(peaks, x, proms;
    strict=true,
    relheight=0.5,
    minwidth=nothing,
    maxwidth=nothing
) -> (peaks, widths, leftedge, rightedge)

Calculate the widths of peaks in x at a reference level based on proms and relheight, removing peaks with widths less than minwidth or greater than maxwidth, if either are given. Returns the modified peaks, widths, and the left and right edges at the reference level.

Peak width is the distance between the signal crossing a reference level before and after the peak. Signal crossings are linearly interpolated between indices. The reference level is the difference between the peak height and relheight times the peak prominence. Width cannot be calculated for a NaN or missing prominence.

The width for a peak with a gap in the signal (e.g. NaN, missing) at the reference level will match the value/type of the signal gap if strict == true. For strict == false, the signal crossing will be linearly interpolated between the edges of the gap.

Examples

julia> x = [0,1,0,-1.];

julia> xpks = argmaxima(x)
1-element Vector{Int64}:
 2

julia> peakwidths(xpks, x, [1])
([2], [1.0], [1.5], [2.5])

julia> x[3] = NaN;

julia> peakwidths(xpks, x, [1])
([2], [NaN], [1.5], [NaN])

julia> peakwidths(xpks, x, [1]; strict=false)
([2], [1.0], [1.5], [2.5])

source

Peaks.peakwidths! — Function

peakwidths!(peaks, x, proms;
    strict=true,
    relheight=0.5,
    minwidth=nothing,
    maxwidth=nothing
) -> (peaks, widths, leftedge, rightedge)

source

Peaks.findnextmaxima — Function

findnextmaxima(x, i[, w=1; strict=true])

Find the index of the next maxima in x after or including i, where the maxima i is either the maximum of x[i-w:i+w] or the first index of a plateau. Returns lastindex(x) + 1 if no maxima occur after i.

If strict is true, all elements in x[i-w:i+w] or the bounds of a plateau must exist and must not be missing or NaN. For strict == false, a maxima is the maximum or first element of all existing and non-NaN or missing elements in x[i-w:i+w] or the bounds of a plateau.