
1. Re: How can I calculate the total duration of readings at a certain value in a time series?
Yuriy Fal Jun 28, 2016 4:02 PM (in response to David Detlefsen)Hi David,
It is unclear if a zero reading
and an absence of reading
is the same or not.
There is a gap for NY from 8:18 till 8:23 (incl).
How could one interpret this gap?
As for LA, if one would count together
the boundary zero points at 8:23 and 8:27 
and the 3 missing points in between 
it would give a total of 5 minute points, not 4.
So the counts would depend on rules (implied or articulated).
With that in mind, please find the attached.
Yours,
Yuri

Example data_YF.twbx 154.3 KB


2. Re: How can I calculate the total duration of readings at a certain value in a time series?
David Detlefsen Jun 30, 2016 6:22 AM (in response to Yuriy Fal)Thanks for the help so far..
Good point and thanks for the clarifying question.
Yes... a reading of 0 is a reading.
And a missing point of the data set is not the same as 0.
Let's set up a rule this way... All values once measured are assumed to be constant until measured again. So if a temp is 80 at 8:01, and the next reading happens to be at 8:06, we assume (due to our rule) that the temperature was 80 for 8:02, 8:03, 8:04, 8:05 until we got another reading at 8:06. The reading that came in at 8:06 may also be 80 or another value. But until we get another value we assume things are as they were at our last measurement.

4. Re: How can I calculate the total duration of readings at a certain value in a time series?
Yuriy Fal Jun 30, 2016 6:46 AM (in response to David Detlefsen)Hi David,
FIRST()==0 is a Table Calculation filter.
When TRUE it leaves only one (first) Cell per Addressing window
(the addressing window includes only [Time] in this case).
As a result, only one value is left on a view for each [Name].
If one removes the filter, more Marks are drawn
on top of each other, hence blurring a view.
Yours,
Yuri

5. Re: How can I calculate the total duration of readings at a certain value in a time series?
Yuriy Fal Jun 30, 2016 7:04 AM (in response to David Detlefsen)Hi David,
Please find the attached w/mod.
Yours,
Yuri

Example data_mod_YF.twbx 164.1 KB


6. Re: How can I calculate the total duration of readings at a certain value in a time series?
David Detlefsen Jul 6, 2016 10:31 AM (in response to Yuriy Fal)How do you create a table calculation filter directly?
I achieved the same result by creating a calculated field and then added that measure to my filters card, but it looks like you created the table calculation filter directly (with no name even?). Can you explain the mechanics of how you created it?

7. Re: How can I calculate the total duration of readings at a certain value in a time series?
Yuriy Fal Jul 6, 2016 11:34 PM (in response to David Detlefsen)Hi David,
This is called "inplace calculation editor".
You just doubleclick on an empty space
somewhere on a view (on Rows, Columns or Details)
and start typing your calculation, then hit Enter.
If calc syntax is right Tableau makes a pill onthefly.
Hope this helps.
Yours,
Yuri
PS I prefer typing on Details :)