Please can anyone help me in fetching data from my SQL Lite Table at every 2 minutes between my start time and stop time
I have two columns Data , TimeStamp and I am filtering between two timestamp and it is working fine but what I am trying to do is to result my data at every 2 minutes interval For example my start time is 2016-12-15 10:00:00 and stop time is 2016-12-15 10:10:00 the result should be 2016-12-15 10:00:00,2016-12-15 10:02:00,2016-12-15 10:04:00 ....
Add, to your where clause, an expression that looks for 2 minute boundaries:
strftime("%s", TimeStamp) % 120 = 0
This assumes you have data on exact, 2-minute boundaries. It will ignore data between those points.
strftime("%s", TimeStamp) converts your time stamp string into a single number representing the number of seconds since Jan 1st, 1970. The % 120 does modulo arithmetic resulting in 0 every 120 seconds. If you want minute boundaries, use 60. If you want hourly, use 3600.
What's more interesting -- and I've used this -- is to take all the data between boundaries and average them together:
SELECT CAST(strftime("%s", TimeStamp) / 120 AS INTEGER) * 120 as stamp, AVG(Data)
FROM table
WHERE TimeStamp >= '2016-12-15 10:00:00' AND
TimeStamp < '2016-12-15 10:10:00'
GROUP BY stamp;
This averages all data with timestamps in the same 2-minute "bin". The second date comparison is < rather than <= because then the last bin would only average one sample whereas the other bins would be averages of multiple values. You could also add MAX(Data) and MIN(Data) columns, if you want to know how much the data changed within each bin.
Related
I am trying to extract the max values of CO2ppm (column E) that were logged every second over 1 hour (column D) for a total of 60 minutes (rows ~3300). I have column D for time (in HH:MM:SS) and CO2ppm (numeric). I have 50 CO2 samples that I collected that correspond with a minute (e.g. I collected sample #1 at minute 20:54 in F2), but the data is logging every second within that minute, and I want the the highest CO2 ppm in that minute).
The =MAX(IF(D:D=A2,E:E)) works to return the max value CO2ppm when I use the target value as the date (A2) for the entire day of sampling, but it does not work when I try to match my target minute (F2, 20:54) with the column D (HH:MM:SS). I tried to convert this column to text using =TEXT(D:D,"H:M") so that the target value will match the values of minute, excluding all of the seconds, but with no luck.
How can I match my minute (F2) with the range of rows that have that minute (20:54:xx, column D) to find the max value in column E?
Example data:
Thank you!
An easy way to do this would be to add a helper column with the timestamp stripped of the second component.
However in case that is not an option, you could use a formula like the following, which strips out the seconds from the timestamps in column D:
=MAX(IF((D2:D5-SECOND(D2:D5)/86400)=F2,E2:E5))
Depending on your version of Excel, you may have to confirm the formula with Ctrl+Shift+Enter.
I have a large dataset of stock prices with 203615 rows and 2 columns(price and Timestamp). in below format
price(USD) | Timestamp
3.5 | 2014-01-01 20:00:00
2 | 2014-01-01 20:15:00
5 | 2014-01-01 20:15:00
----
4 | 2014-01-31 23:00:00
5 | 2014-01-31 23:00:00
4.5 | 2014-01-31 23:00:00
203615 2.3 | 2014-01-31 23:00:00
Time stamp varies from "2014-01-01 20:00:00" to "2014-01-31 23:00:00" with intervals of 15min(rounded to 15min). i have several transactions on same timestamp.
I have to group rows based on timestamp with difference of one day, and caluclate min,max and mean of the price and no of rows within the timestamp limits and assign them to a row in a new dataframe for every iteration until it reaches the end timestamp("2014-01-31 23:00:00") from starting date('2014-01-02 20:00:00")
note: iteration has to be done for every 15min
i have tried while loop. please help me with this and suggest me if i can use any packages
This is my own code which I used as a way of creating a window of time (the prior 24 hours) to iterate over and create min and max values for a project I am working on...
inter is the inteval I worked on in the loop
raw is the data frame name
i is the specific row from which the datetime column was selected from raw
I started my intervals at 97th row ( (i in 97:nrow(raw) ) because the stamps were taken at 15 minute intervals and I wanted a 24 hour backward window, so I needed to leave 96 intervals to pull from...I could not reach back into time I had no data for...so I started far enough into my data to leave room for those intervals.
for (i in 97:nrow(raw)){
inter=raw$datetime[i] - as.difftime(24, unit='hours')
raw$deltaAirTemp_24[i] <-max(temp$Air.Temperature)- min(temp$Air.Temperature)
}
The key is getting into a real date time format. Run str() on the field with the dates, if the come back as anything but Factor, use:
as.POSIXct(yourdate$field, %Y-%m-%d %H:%M:%S)
If they come back from str(yourdatecolumn here) as FACTOR then wrap it in as.POSIXct(as.character(yourdate$field), %Y-%m-%d %H:%M:%S) to be sure it does not coerce the date into a Level number then time..
Get them into a consistent date format, then construct something like above to extract the periods you need. difftime is in the base package and works well you can use positive and negative intervals with it. I hope his helps!
I have a csv file that contains many thousands of timestamped data points. The file includes the following columns: Date, Tag, East, North & DistFromMean. The following is a sample of the data in the file:
The data is recorded approximately every 15 minutes for 12 tags over a month. What I'm wanting to do is select from the data, starting from the first date entry, subsets of data i.e. every 3 hours but due to the tags transmitting at slightly different rates I need a minimum and maximum value start and end time.
I have found the a related previous question but don't understand the answer enough to implement.
The solution could firstly ask for the Tag number, then the period required perhaps in minutes from the start time (i.e. every 3hrs or 180 minutes), the minimum time range and the maximum time range, both of which would be constant for whatever time period was used. The minimum and maximum would probably need to be plus and minus 6 minutes from the period selected.
As the code below shows, I've managed to read in the file, change the Date format to POSIXlt and extract data within a specific time frame but the bit I'm stuck on is extracting the data every nth minute and within a range.
TestData<- read.csv ("TestData.csv", header=TRUE, as.is=TRUE)
TestData$Date <- strptime(TestData$Date, "%d/%m/%Y %H:%M")
TestData[TestData$Date >= as.POSIXlt("2014-02-26 7:10:00") & TestData$Date < as.POSIXlt("2014-02-26 7:18:00"),]
I am trying to extract data from my workbook because I made the workbook wrong but I want to keep the data. So I have to go through each worksheet and extract the specific bits of data I need. (Repetitive task = vba code to the rescue)
I'm done, but I have one nasty little problem.
I am using ws.Range("C13") to extract each cell that I need. It's a cell that has time values like 10:00 or 22:13. When I debug.print that value however I get a decimal. Why? How do I prevent it from converting my "10:30" to "0.4375"
From what I can tell, the decimal isn't even related to the time value.
WRONG it is simply the time value as a representation of a 24 hour period. So it is related. But still.
ws.Range("C13") is the equivalent of ws.Range("C13").Value which returns the underlying data from that cell.
If instead you use ws.Range("C13").Text, you will get the displayed text from the cell. If you have set a specific date/time format for that cell then calling ws.Range("C13").Text should return text in that specific format
The time values are correct; it's the way Excel stores date and time values internally.
Dates are stored as floating point values, where the whole portion represents the number of days since 12/30/1899 00:00.00 (date 0.0) and the decimal part represents the fractional part of a single day (eg., 408875.5 represents 11/28/2011 12:00:00 PM).
Here are some conversion factors you might find useful:
Decimal value Time Value Calculation
============= ========== ===========
0.00094444444 12:01:00 AM 1.0 / 24 / 60 (1 day/24 hours/60 minutes per hour)
0.01041666666 12:15:00 AM 1.0 / 24 / 60 * 15
0.02083333333 12:30:00 AM 1.0 / 24 / 60 * 30
0.04166666666 01:00:00 AM 1.0 / 24
hours = MOD(INT(0.tttttttt*24), 24)
minutes = MOD(INT(0.tttttttt*24*60), 60)
seconds = MOD(INT(0.tttttttt*24*60*60), 60)
milliseconds = MOD(INT(0.tttttttt*24*60*60*1000), 1000)
I need to prepare a yearly management report to show the total overtime (OT) work hours and minutes of all staff within time range and month.
The time format in ms sql 2000 database is as follows:
Each record will contains the FROM date & time and TO date & time
The report layout is as follows:
I had no idea how to divide and calculate the total hours & minutes within the time range as each OT records will overlap several time range and date.
Please help. Thanks.
Joe
The SQL DateDiff function can be used to compute the number of minutes, i.e.
declare #fromDT datetime
declare #toDT datetime
set #fromDT = '10/22/2011 18:30'
set #toDT = '10/22/2011 22:45'
select #fromDT,#toDT,DATEDIFF(mi,#fromDt,#toDt),
ltrim(str(DATEDIFF(mi,#fromDt,#toDt)/60))+':'+
ltrim(str(DATEDIFF(mi,#fromDt,#toDt)%60)) as HoursMin
Returns
StartTime End Time Mins HoursMin
2011-10-22 18:30:00.000 2011-10-22 22:45:00.000 255 4:15