Hello
I would like to plot a Power Frequency Distribution Chart similar to what Allen, Coggan, and Mcgregor (3rd Edition) show on page 28 in Fig. 3.1
Intervals.icu does some like this already but I need smaller Intervals for the bars (e.g. steps for 5W, 10W etc.).
A script to create a custom chart would be highly appreciated.
Here is a start. It assumes your data has 1 second per point and uses a 5 second moving average of power (power data is spikey). Intervals.icu calculates these things on an interpolated power stream with 1 second per tick. I need to make that available to scripts to do this properly.
{
let watts = icu.streams.fixed_watts
let maxWatts = 0
for (let w of watts) if (w > maxWatts) maxWatts = w
let bucketSize = 5
let buckets = []
let x = []
for (let i = 0; i <= (maxWatts / bucketSize); i++) {
buckets.push(0)
x.push(i * bucketSize)
}
let totWatts = 0
let window = 5
for (let i = 0; i < window; i++) if (watts[i]) totWatts += watts[i]
for (let i = window; i < watts.length; i++) {
let w = totWatts / window
let bucket = Math.floor(w / bucketSize)
buckets[bucket] += w
if (watts[i]) totWatts += watts[i]
if (watts[i - window]) totWatts -= watts[i - window]
}
let data = [
{
x: x,
y: buckets,
type: 'bar',
marker: {
color: '#63c',
opacity: 0.7
}
}
]
let layout = {
title: {
text: "Time in " + bucketSize + "w buckets"
},
margin: {
l: 30,
r: 20,
t: 20,
b: 30
}
}
chart = { data, layout }
}
Thanks a lot!
However, I do not understand the meaning of the unit used on the y-axis. Can you elaborate?
Is there a way to plot the same distribution not only for an activity but for all cycling activities in a specific time frame or season?
Btw. maybe an easier solution would be to allow users to use the existing plot (see above) and add options for smaller buckets / show more ticks?
You can’t plot this histogram for lots of activities yet. That is on the todo list. I have made the bucket size for power and heart rate histograms configurable. Click the pencil icon at the bottom left of the chart:
I also fixed a bug that was hiding the power and bpm bucket numbers on the marker.
Nice one! That is a great addition!
One more feature request or idea to improve your customize option for the power and hr distributions charts.
Currently, the y-axis does not adjust its range when you change the bucket. Maybe add a line of code to make the y-axis range depend on the largest value (time in minutes or seconds), given for the selected (default) bucket size? Then it should be perfect. 
It does adjust the range but there is always a chunk of time in the 0 watts bucket. This shows up more when there are many small buckets. I have added an option to exclude the 1st bucket from the chart:
