How to use groupsummary to group by hour-of-year

Question

Dino Bellugi le 30 Juin 2023

0
Lien

Utiliser le lien direct vers cette question

https://fr.mathworks.com/matlabcentral/answers/1990428-how-to-use-groupsummary-to-group-by-hour-of-year

Réponse apportée : Peter Perkins le 17 Juil 2023

The "groupsummary" function offers a convenient way to group variables in a table and apply functions such as computing the mean.

For example, if I want to compute the day-of-year mean of a variable named "foo" in a table "myTable" containing daily data with timestamp "date", I would use the command:

myDoyTable = groupsummary(myTable, "date","dayofyear","mean","foo");

This is great for daily data, but I am stumped in the case of hourly data.

Suppose I want to do a similar thing, but now myTable contains hourly data and date has an hourly timestamp.

Ideally I would want to use a command such as:

myDoyTable = groupsummary(myTable, "date","hourofyear","mean","foo");

Unfortunately, there is no "hourofyear" option (though there is hour of day, minute of hour, and many more).

Can anyone suggest a workaround?

Thanks,

-Dino

0 commentaires
Afficher -2 commentaires plus anciensMasquer -2 commentaires plus anciens

Connectez-vous pour commenter.

Connectez-vous pour répondre à cette question.

Answer 1

the cyclist le 30 Juin 2023

0
Lien

Utiliser le lien direct vers cette réponse

https://fr.mathworks.com/matlabcentral/answers/1990428-how-to-use-groupsummary-to-group-by-hour-of-year#answer_1265588

The groupbin option "hour" doesn't do what you want?

(If not, can you upload a sample of input and output data indicating what you want? I'm having a difficult time understanding.)

4 commentaires
Afficher 2 commentaires plus anciensMasquer 2 commentaires plus anciens

Dino Bellugi le 30 Juin 2023

Thank you for your response, let me try again:

Given a table "myTable" with 20 years of hourly data (each entry with a time stamp "time" like 01-Jan-2014 01:00:00, and a variable "foo" like 0.00425), the command:

doyTable = groupsummary(myTable, "time","dayofyear","mean","foo");

produces a table "doyTable" with 366 rows (one for each day of the year, including a bin for leap years) that contain the mean of "foo" for day 1 across the 20 data years, day 2 across the 20 data years, and so forth.

Similarly, the command:

hodTable = groupsummary(myTable, "time","hourofday","mean","foo");

produces a table "hodTable" with 24 rows (one for each hour of the day) that contain the mean of "foo" for each hour of the day across the 20 data years.

What I would like is the equivalent of a command:

hoyTable = groupsummary(myTable, "time","hourofyear","mean","foo");

This, in my ideal world, would produce a table that has 366 * 24 rows, meaning one row for each hour of the year (accounting for leap year bins). Each row would in this case contain the mean of foo for each specific hour of the year, across the 20 years of data. The entries would thus be the mean of 20 values for each hour of a year (except for the leap year bins, which would only have a mean of 5 values each).

In simpler words, I'm after a grouping "hourofyear" that would allow me to compute the mean of a variable on each specific hour of the year across the number of years of data available.

I hope that was more clear.

Thanks,

-d.

Dino Bellugi le 2 Juil 2023

Thanks, that's clever! I will give it a try and let you know..

Dino Bellugi le 2 Juil 2023

Cleaned_Hourly_AbiskoPalsa_Fen2_vLL2_SAMPLE.zip

Here is the data, BTW, apologies for not uploading it earlier. I'm interested in the hour of year mean for column AP, namely "Fch4_f_1_1_1". I had to chop off the data file after a few years, due to size limitations. Feel free to take it for a spin, cyclist! Thanks again, -d.

Connectez-vous pour commenter.

Answer 2

Peter Perkins le 17 Juil 2023

0
Lien

Utiliser le lien direct vers cette réponse

https://fr.mathworks.com/matlabcentral/answers/1990428-how-to-use-groupsummary-to-group-by-hour-of-year#answer_1274503

Ouvrir dans MATLAB Online

Is this really "hour of year", a value that runs from 0 to 8784? In the same way that day of year is just

dt = datetime(2023,7,17,14,15,0)
dt = datetime
   17-Jul-2023 14:15:00
doy = between(dateshift(dt,"start","year"),dt,"days") % or maybe - caldays(1)
doy = calendarDuration
   197d

hour of year is just

hoy = between(dateshift(dt,"start","year"),dt,"time")
hoy = calendarDuration
   4742h 15m 0s
hoy = floor(time(hoy),"hours"); hoy.Format = 'h'
hoy = duration
   4742 hr

If you add an HoY grouping variable to your table, groupsummary can group by that.

0 commentaires
Afficher -2 commentaires plus anciensMasquer -2 commentaires plus anciens

Connectez-vous pour commenter.

How to use groupsummary to group by hour-of-year

0 commentaires
Afficher -2 commentaires plus anciensMasquer -2 commentaires plus anciens

Réponses (2)

4 commentaires
Afficher 2 commentaires plus anciensMasquer 2 commentaires plus anciens

0 commentaires
Afficher -2 commentaires plus anciensMasquer -2 commentaires plus anciens

Voir également

Catégories

Tags

Produits

Version

Community Treasure Hunt

How to use groupsummary to group by hour-of-year

0 commentaires Afficher -2 commentaires plus anciensMasquer -2 commentaires plus anciens

Réponses (2)

4 commentaires Afficher 2 commentaires plus anciensMasquer 2 commentaires plus anciens

0 commentaires Afficher -2 commentaires plus anciensMasquer -2 commentaires plus anciens

Voir également

Catégories

Tags

Produits

Version

Community Treasure Hunt

0 commentaires
Afficher -2 commentaires plus anciensMasquer -2 commentaires plus anciens

4 commentaires
Afficher 2 commentaires plus anciensMasquer 2 commentaires plus anciens

0 commentaires
Afficher -2 commentaires plus anciensMasquer -2 commentaires plus anciens