I am struggling to create this calculation.
I need to create a rolling count of all of a columns values BETWEEN two dates. 12 to 24 months ago.
I do not want to do this by limiting data, I need it in the custom expression due to other work.
Currently I have this equation. I thought this would at least calculate all the values since two years ago but it fails to do that as well. Does anyone have a simpler way to calculate 12 to 24 months ago?
(((Count(If(((Month([DATE])>=Month(DateAdd("mm",-24,DateTimeNow())))
and (Year([DATE])>=Year(DateAdd("yy",-2,DateTimeNow())))),
[EXTRAPOLATEDPRESSURE],null)))))
Solved. I was making it to complex with the Month and Year aspects.
Count(If(([DATE]>=dateadd("mm",-24,DateTimeNow())) and ([DATE]<=dateadd("mm",-12,DateTimeNow())),
[EXTRAPOLATEDPRESSURE],null))
Related
I just stumbled on an interesting problem when trying to calculate birthday from age. Basically the idea is to substract a number of years, months and days from the current date. However depending on the order of subtraction eg smaller to larger units or vice versa the result is different.
For example we need to substract 55 years 3 months and 14 days from 2021-01-13
If I subtract the years first the result will be 1965-09-29
If I subtract the days first the result will be 1965-09-30
It all comes from the difference between the number of days in a month. Now I'm wondering which is the generally accepted order.
This is going to be a bit hard to explain but
I have 2 dates, i'm interested in the day and month unless the 2 dates have the same year
2015/12/30 and 2019/01/04
ignoring the year part (kind of) the result i'm expecting 6 days difference for the 2 dates above
if i was to use date.DayOfYear i would get 364 (2015/12/30) and 4 (2019/01/04) respectively
however if the years are same then
2019/01/04 2019/12/30 then the result i'm expecting is 359 days difference
is there a clever way of doing this without peppering the code with if statements?
If the year difference was just 0 or 1, then you could just convert both dates to an absolute value (in seconds, ms, unix time or whatever), subtract the 2 values and convert it to full days. But if you have more than 1 year diff (as 2015 and 2019), then you have to have an "if" an think about what are you actually trying to do there. You shouldn't use DayOfYear, because some years have 366 days, so you can't be sure that 364 corresponds to 1 or 2 days left in that year.
I am simply trying to display the difference between to dates, but have the result contain a decimal. For example, for the two dates 8/1/2009 and 7/6/2010, I would like a return of about "0.9" or something like that. I can get the 339 days result by simply subtracting one cell from another, but when I use "Y", it only gives whole numbers. Of course the date format boxes under the Cell section of the format and options are there, but they infuriatingly stop at "Week" and don't offer months or years. I don't want, for example, "10 months, 25 days". I'd really like it to simply be years with decimals, like "1.5" years instead of x amount of weeks or months. Any help appreciated..thanks.
You're after the YEARFRAC function:
Finds the fraction of a year represented by the number of whole days between two dates
Alternatives can also be found in the DATEDIF function, which allows you to return the result in a number of different units, but I'll let you read around that for yourself.
I wanted to know if it was possible to use a date function for last week's date ranges. Currently I'm using the method as below.
Thanks.
datetime_date('Sale.Date') >= datetime_date(2016,04,18)
and
datetime_date('Sale.Date') <= datetime_date(2016,04,24)
Not a great solution but:
--datetime_date(datetime_year(#TODAY), datetime_month(#TODAY), datetime_day(#TODAY)-7)
This will work for all but 7 days of the month.
You could also get a rough estimate by calculating the following (note that you will use the method I outline and not the equations. you must copy paste the equations into their designated locations).
--a=date_in_years(#TODAY)-7/365
--year=a-(a mod 1)+1900
--month=(a mod 1)-((a mod 1) mod 1/12) *12
etc. then entering these formulas into this formula:
--datetime_date(year,month,day)
OR you can use SQL to calculate a 7 day difference. This will be the accurate and easy but would require the correct setup.
It is a little unclear what you are looking for exactly; what do you mean by "last week"? Is that the 7 days prior to today or is it the last calendar week? If it's the calendar week, which definition are you using? What day of the week does a week start? When does the first week of the year start?
Unfortunately, these definition vary between different parts of the world and even for different uses within countries.
Dates in SPSS Modeler are all represented as the number of seconds from Jan. 1st, 1900, so if you are looking for the dates of the past 7 days, the calculations are fairly trivial as you can use the datetime_in_seconds() function to get the numeric representation of any date or timestamp.
If you are looking for calendar weeks, things get a little more complicated, but I should be able to help with that, too, if you can answer the above questions.
For SPSS Modeler you can use a Derive Node and I see two options to do that:
A)
Derive Node: date_weeks_difference(date1,date2)
And then use a Filter node to keep only the derive node = 1
B)
Or you can use a function inside the Derive Node, creating a dummy variable:
if date_weeks_difference(date1,date2)= 1 then 1 else 0 endif
Say I have a data set that has x-sections of country (US, CANADA) and then state/province then year then week. My data stack has 2 countries, 57 states/provinces, 3 years, and 52 weeks. I wanto to create a variable revenue that for each week, sums the last 52 weeks within the x-section.
Right now i have a loop but its very, very slow.
for each countries,
for each state,
for the last 2 years,
for each week,
sum the last 52 elements
Does anyone know how I can do this with vectorization?
You might want to look into using the function s=sum(X,DIM). Without more info about your dataset (please provide example), we cannot go into great detail.
For weighted sums over rolling window, filter() can work well.