Detect DFA-a1 threshold crossings

Finds where a rolling alpha1 trajectory crosses the two exercise-intensity markers of Gronwald & Rogers: AT1 (aerobic threshold, alpha1 = 0.75) and AT2 (anaerobic threshold, alpha1 = 0.5).

Usage

dfaThresholdCrossings(alpha1, at1 = 0.75, at2 = 0.5)

Arguments

alpha1

Numeric vector of rolling alpha1 values (e.g. the alpha1 column from ecgDFArolling).

at1, at2

Threshold values (defaults 0.75 and 0.5).

Value

A list with at1, at2 and integer vectors at1_crossings / at2_crossings giving the indices immediately before each crossing (either direction).

See also

ecgDFArolling

Examples

a1 <- seq(1.2, 0.3, length.out = 20)   # descending intensity ramp
dfaThresholdCrossings(a1)
#> $at1
#> [1] 0.75
#> 
#> $at2
#> [1] 0.5
#> 
#> $at1_crossings
#> [1] 10
#> 
#> $at2_crossings
#> [1] 15
#>