Dear All,
The year 2019 has 365 days.
The “WeatherData” output shows 357 data for Istanbul city.
How do I use the Datepath command or any other commands to find the missing dates?
I appreciate your time.
Alex
Alex,
I had the same problem several times. Thank you for the inquiry.
Cheers,
Hello friends, here is one way:
{dateStart, dateEnd} = DateObject /@ {{2019, 1, 1, 0, 0, 0}, {2019, 12, 31, 0, 0, 0}};
data = WeatherData["Istambul", "WindSpeed", {dateStart, dateEnd, "Day"}];
allDays = DateRange[dateStart, dateEnd];
DateObject /@ Complement[DateString /@ allDays, DateString /@ data["Dates"]]
Hi Henrik,
I was wondering why the conversion to DateString is required. Here is why
allDays[[1]] // InputForm
(* DateObject[{2019, 1, 1, 0, 0, 0.}, "Instant", "Gregorian", -5.] *)
data["Dates"][[1]] // InputForm
(* DateObject[{2019, 1, 1, 0, 0, 0}, "Instant", "Gregorian", -5.] *)
The DateObject generated by DateRange has Real seconds 0. while the DateObject in WeatherData has Integer seconds 0. Even though the date specifications passed to DateRange have Integer seconds. This seems like an oversight or bug in the implementation of DateRange. Thanks for revealing this, I will keep it in mind when dealing with DateRange.
Hi Rohit,
I freely admit that I could not make sense of why these DateObject[] do not work in combination with Complement[] - now I know, many thanks!
Regards – Henrik
Hi Alex,
glad to help (and please just call me Henrik)! Yes, I think interpolation is a good way. And
data["PathFunction"]
gives already the respective InterpolatingFunction. Regards – Henrik
I appreciate your help, Henrik.
I tried to fill in the missing data for 23rd January. I got a strange value!
It is the same for other dates.
In[16]:= data["PathFunction"];
In[15]:= %8[23]
Out[15]= Quantity[249937., ("Kilometers")/("Hours")]
Alex,
You need to pass an AbsoluteTime to the PathFunction.
data["PathFunction"][AbsoluteTime[{2019, 1, 23}]]
(* Quantity[13.52, ("Kilometers")/("Hours")] *)
Many thanks, Rohit.