Skip to main content
cancel
Showing results for 
Search instead for 
Did you mean: 

Earn the coveted Fabric Analytics Engineer certification. 100% off your exam for a limited time only!

Reply
vrmntmtt
Frequent Visitor

Calculating the duration between rows by tagname

Hi,

 

I have a problem, and I could not find it immediatly on this forum.

I have a lot of data from a light sensor, and we want to know the % of the time it was giving a signal (value = 1).

 

We have three sensors: LDR1, LDR and LDR3. Each time one changes, we get the values of all three sensors.

So I have to take the sum of the duration per sensor when it gives value 1, and devide it by the total reading time.

 

For example:

LDR2 gives value 1 from 4/08/21 at 14:48:51 until 4/08/21 14:48:58 (see picture below). So this gives a duration of 0:00:07.

Schermafbeelding 2021-08-24 130007.png

 

Thank you in advance.

4 REPLIES 4
V-pazhen-msft
Community Support
Community Support

@vrmntmtt 
This is error is because you compare a integer with a text value, please share a sample in a format we can copy and past, so we can test out to reach your expected outcome.

 

 

Paul Zheng _ Community Support Team

Hi,

 

Sorry for the late reply. But I solved it a while ago.

 

I made a calculated column 'stopped at' and it selects the next different date. Except at the end, then Power BI uses Now

 

I used the following formula:

Stopped_at = IF(CALCULATE(MIN('8xLight_B2'[received_at]), FILTER('8xLight_B2',[received_at] <> EARLIER([received_at]) && [received_at] > EARLIER('8xLight_B2'[received_at])))>0,CALCULATE(MIN('8xLight_B2'[received_at]), FILTER('8xLight_B2',[received_at] <> EARLIER([received_at]) && [received_at] > EARLIER('8xLight_B2'[received_at]))),NOW())
 
Then I made another calculated column that takes the time difference between the start and end time.
 
vrmntmtt_0-1635433436084.png

 

amitchandak
Super User
Super User

@vrmntmtt , Create a new column like this and use that

 

New column =
var _max = maxx(filter(Table, [received_at] <earlier([received_at]) && [Tag] =earlier([Tag]) ),[received_at])
var _val = maxx(filter(Table, [received_at] =_max && [Tag] =earlier([Tag]) ),[value])
return
if(_val =1 && [Value]=1 , datediff(_max,received_at, second), blank())

@amitchandak Thank you for your fast treply.

However, the formule gives an error at the underlined text:

New column =
var _max = maxx(filter(Table, [received_at] <earlier([received_at]) && [Tag] =earlier([Tag]) ),[received_at])
var _val = maxx(filter(Table, [received_at] =_max && [Tag] =earlier([Tag]) ),[value])
return
if(_val =1 && [Value]=1 , datediff(_max,received_at, second), blank())

 

Update:

I was working in the query, not the data format for adding a column (my bad sorry).

But I recieved the following error while adding the column: DAX comparison operations do not support comparing values of type Text with values of type Integer. Consider using the VALUE or FORMAT function to convert one of the values.

Helpful resources

Announcements
April AMA free

Microsoft Fabric AMA Livestream

Join us Tuesday, April 09, 9:00 – 10:00 AM PST for a live, expert-led Q&A session on all things Microsoft Fabric!

March Fabric Community Update

Fabric Community Update - March 2024

Find out what's new and trending in the Fabric Community.