I download adjusted time series from AlphaVantage using the following call (you need to insert your own API key):
https://www.alphavantage.co/query?function=TIME_SERIES_daily_adjusted&symbol=^GDAXI&outputsize=full&apikey=yourAPIkey
Next, I look at one particular (and faulty) data point at date 2003-04-18:
"5. adjusted close": "766464.0000"
Then, I reload the exact same API call and check the same data point again. However, this time there is a different value for adjusted close here! Every time I reload, different value (and always wrong, too). Why is this happening and how do I fix this wrong data?
For those who come across the same problem with AlphaVantage data, I try to answer my own question.
The random data problem only occurs on some (not all) non-trading days. For example, the above date is Good Friday in 2003. I have written a function to filter out all non-trading days from the downloaded AlphaVantage data, and that "fixed" the problem of the random-data days.
Related
I currently have a coreData entity called CalorieProgress, which I would like to reset all variables (calorieProgress, fatProgress) to 0, every day.
I am still quite new to SwiftUI, and the only method I thought of as of now, is to add a Date Created variable to this entity called created, and when the user opens the app, to check if that date was yesterday. If so set all values to 0 etc.
Is there a more efficient way to do this?
Thanks
Your design is good and simple, and a reasonable choice if you're getting started.
It can have trouble, however, when people move between time zones. It is even possible for people to move to previous days this way (most dramatically when they cross the date line). There is no single answer to that question. Your app has to decide what it means by "today" when strange clock events happen. (Users also sometimes change their clock, and you want to behave "reasonably" in those cases, even if it means the data is wrong.)
Having built several of these, my suggestion is to just store raw, immutable, data records, and work out things like resetting values when you're running queries. For example, to work out how many calories someone has burned "today" doesn't require that you set any value to zero. You can just perform a query for records that occur after some time and sum their calories (you can even do this with aggregate queries directly on Core Data).
Core Data can be very fast, but if these queries become too slow, you can store daily aggregation records in Core Data. But keeping the original raw data means that those are really just caches and you can throw them away and recompute any time you need to.
Assuming that a new day starts as midnight (I've worked on apps where days started "when the user wakes up in the morning" which is much more complicated...) you should also be aware of significantTimeChangeNotification which is posted at midnight (and a few other times). You can't use this to launch your app or do processing in the background, but it's very nice for updating your UI if the user has the app open.
I'm building a Grafana dashboard with some Stat panels that show average, minimum, and maximum time values (see below) for specific fields in my database. I'm storing the data in seconds and setting the value's units to seconds after which the panel displays the time in weeks, days, hours, etc. For the sake of consistency, I would like everything to be shown in days but I haven't been able to find a way to force units for the output value. If it's possible to do this, could someone please point me to some docs, or something that could show me which configurations to make in my panels?
So far, I've tried (without success):
Configure each panel to use units of days
The result of this was that everything showed up in years, etc.
Configure each panel to create a new field by performing a binary calculation where I converted from seconds to days and then I updated the units to be days
The result was that the values were not changed at all -> instead of showing X days, or whatever, it just showed the value in seconds without the units. I'm not sure what I messed up there, but it didn’t change anything.
I found this link that discusses setting a time range for queries
This didn’t end up being useful for what I was trying to do because it was actually geared towards changing the query to a specific date range rather than the output.
I looked through the transformations documentation, stat panel documentation, and a few other panel documentation pages in an effort to see if there was any information on how to do it but I was unable to find anything on forcing the output value to use a specific unit.
Edit:
So I kept messing around with the dashboard and got a solution that works - i.e. it's a "good-enough" solution (see below) - but, now, I'm curious if it's possible to show the units along with the value without it converting it to some other unit. Does anyone have any ideas about this?
One thing to note is that the data for this image is different than the data for the previous one so I'm expecting an inexact conversion to days.
You can use a custom unit. It is a bit tricky to enter the unit in the UI because of the automatic selection but if you enter i.e. "days" (without the quotes) in the Unit field ans instead of leving the field with tab or mouse click use the scrollbar of the combobox and select the last entry "Custom Unit: days".
Hope it helps. And for the record: I am using Garafana 7.1.4
I have an InfluxDB database with only x11 data points in it. These data are not displaying correctly (or at least as I would expect) in Grafana when the time between them is shorter than 1ms.
If I insert data points 1 ms apart, then everything works as expected and I see all x11 points at the correct times, as shown below.:
However, if I delete these points and upload new ones but this time one point per 100 μs, then although the data displays correctly in InfluxDB, in Grafana I see only two points in my graph:
It seems like the data is being rounded/binned to the nearest millisecond, an that this is related to the “precision=ms” setting in the query here:
but I cannot find any way to change this setting. What is the correct way to fix this?
You can't configure Grafana to support different time precision for the InfluxDB. It is hardcoded in the source code: https://github.com/grafana/grafana/blob/36fd746c5df1438f27aa33fc74b24be77debc7ff/public/app/plugins/datasource/influxdb/datasource.ts#L364 (It may need to be fixed in multiple places of the source, not only in this one.)
So the correct way to fix it is to code it, which is of course not in the scope of this question.
I have a function that takes the step data for every day until a point, which is yet to be determined. What I need is a way to determine the day that HealthKit began receiving step count input. I tried to have it repeat until it detects 3 days of zero activity, but that seems too unspecific. Is there an object for the start date?
I don't think that there is an object for the start date readily available, as far as I know.
One solution could be to pull all the data using a HKStatisticsCollectionQuery by day without any predicate ordered by the date, and the first date in the results should be the start date.
Hope this helps.
I am working on a simple application that I need to be run as a service and report gps position every 3 minutes. I already have a working example based on the tutorial, but still have the followin doubts.
The starting of the service GPS1.Start(5*60*1000, 0)
Says first parameter is time lapse, and 2nd parameter is distance difference, How is determined, based on prior position ?
If I want to do what I stated before and I am scheduling / starting service every 3 minutes, this means I will need to ask a GPS1.Start(0,0) to get latest fix? what would be the gain to use the parameters?
I trying in a NexusOne and the Time object comes with local time, I have to do this to make it UTC but this is a tweak to the code. Is this a standard or could It change based on Phone model ? hora=DateTime.Date(Location1.Time + 6*DateTime.TicksPerHour)
thanks
If you are only interested in a single fix each time then you should pass 0, 0. These values affect the frequency of subsequent events.
You can find the time zone with the code posted here: GetTimeZone