cancel
Showing results for 
Search instead for 
Did you mean: 
Reply

Moving Range DAX (subtract previous row values from earlier DateTime)

Hi, 

Need help with DAX to calculate "Moving Range".

 

TimeSPC- Time when values are measured. 

MeasureValue- dimension in mm

Moving Rane= Absolute difference between MeasureValue compare to earlier TimeSPC

 

2018-02-22 14_32_35-Start.jpg

 

Sample pbix  

https://1drv.ms/u/s!ArjVwEnHONXNghspzwtVdKi9T6KS

 

2 ACCEPTED SOLUTIONS

Accepted Solutions
Super User
Super User

Re: Moving Range DAX (subtract previous row values from earlier DateTime)

@vincentakatoh

 

Try this MEASURE

 

Moving Range =
VAR EarlierTime =
    CALCULATE (
        MAX ( data1[TimeSPC] ),
        FILTER (
            ALLSELECTED ( data1[TimeSPC] ),
            data1[TimeSPC] < SELECTEDVALUE ( data1[TimeSPC] )
        )
    )
VAR EarlierMeasureValue =
    CALCULATE ( SUM ( data1[MeasureValue] ), data1[TimeSPC] = EarlierTime )
RETURN
    ABS ( EarlierMeasureValue - SUM ( data1[MeasureValue] ) )
Super User
Super User

Re: Moving Range DAX (subtract previous row values from earlier DateTime)

@vincentakatoh

 

Try this MEASURE

 

MRBR = AverageX(ALLSELECTED(data1[TimeSPC]),[MovingRange])
10 REPLIES 10
Super User
Super User

Re: Moving Range DAX (subtract previous row values from earlier DateTime)

@vincentakatoh

 

Try this MEASURE

 

Moving Range =
VAR EarlierTime =
    CALCULATE (
        MAX ( data1[TimeSPC] ),
        FILTER (
            ALLSELECTED ( data1[TimeSPC] ),
            data1[TimeSPC] < SELECTEDVALUE ( data1[TimeSPC] )
        )
    )
VAR EarlierMeasureValue =
    CALCULATE ( SUM ( data1[MeasureValue] ), data1[TimeSPC] = EarlierTime )
RETURN
    ABS ( EarlierMeasureValue - SUM ( data1[MeasureValue] ) )

Re: Moving Range DAX (subtract previous row values from earlier DateTime)

Hi @Zubair_Muhammad

 

Thanks!

 

One more question, can advise the DAX to calculate "Average of Moving Range (MRbar)"? 

 

My end goal is to calculate the Cpk of the specific MeasureValue. Cpk= MRbar/1.128. 

 

Re: Moving Range DAX (subtract previous row values from earlier DateTime)

Hi @Zubair_Muhammad

 

1) Wrap a "ISBLANK" around MovingRange, such that the Moving Range for 1st row is blank(). 

 

MovingRange = 
IF(ISBLANK(data1[EarlierTime]);blank();(
VAR EarlierTime = CALCULATE ( MAX ( data1[TimeSPC] ); FILTER ( ALLSELECTED ( data1[TimeSPC] ); data1[TimeSPC] < SELECTEDVALUE ( data1[TimeSPC] ) ) ) 
VAR EarlierMeasureValue = CALCULATE ( SUM ( data1[MeasureValue] ); data1[TimeSPC] = EarlierTime ) 
RETURN ABS ( EarlierMeasureValue - SUM ( data1[MeasureValue] ) ) ))

 

 

2) Que: Can advise the DAX for Average of Moving Range (ie. MRbar)?

 

3) To correct myself, my goal is to calculate the sigma value = MRbar/1.128 (not Cpk and 1.128 is a constant). 

https://1drv.ms/u/s!ArjVwEnHONXNghx02BIdTGGtSrlZ

 

Super User
Super User

Re: Moving Range DAX (subtract previous row values from earlier DateTime)

@vincentakatoh

 

Sorry.... i had to go out...Just returned

 

So average is it a one single figure or is it computed across days??

Super User
Super User

Re: Moving Range DAX (subtract previous row values from earlier DateTime)

@vincentakatoh

 

Try this MEASURE

 

MRBR = AverageX(ALLSELECTED(data1[TimeSPC]),[MovingRange])

Re: Moving Range DAX (subtract previous row values from earlier DateTime)

@Zubair_Muhammad

Thanks. This is really awesome. A DAX dummy can only achieve so much because of great folks like you!

 

rgds, 

Vincent

Mattk3 Frequent Visitor
Frequent Visitor

Re: Moving Range DAX (subtract previous row values from earlier DateTime)

Hi

 

This topic is really usefull and solution works very well

I try to adapt the code to add a process filter because we have many different measure on a machine and my goal is to filter the process that I want.

 

My data:

Capture.PNG

 

 

 

 

 

 

 

 

 

On measurement "Ealier" and "MovingRange" I have replaced [TimeSpc] by [Index], the MovingRange graph works correctly but I have trouble with the measurement of "MRBar" where the result is empty (probably due to blank value). 

 

How can I have a mean measurement of the moving range with the same value that I have on the graph with the mean?

Capture.PNG

Any help will be really appriciated :-)

Re: Moving Range DAX (subtract previous row values from earlier DateTime)

@Mattk3

The line chart visual provides an option to add a average line automatically. Does that helps?

 

btw.. On a side note, on Upper and Lower Control Limit for Xbar Chart, i did not find a way to auto calculate both UCL and LCL, then it came to my mind it is not requried. Reason being, from a statisic perspective, the UCL and LCL should be locked once process is stable. UCL and LCL should not change with new data.

 

Linechart.JPG

Mattk3 Frequent Visitor
Frequent Visitor

Re: Moving Range DAX (subtract previous row values from earlier DateTime)

@vincentakatoh Yes for the mean MRBar average line automatically this is what I've done on my MR chart and it works well. My issue is that I need to have this value on a measurement to calculate after the Cpk.

 

If I used this calculation:       

MRBar = AverageX(ALLSELECTED(List1[Value]); [MovingRange]) --> result is Empty

 

Capture.PNG

 

Seems that the mean function on the graph is different than this calculation.

Is it possible to catch the mean value from the graph directly?

 

Agree for UCL and LCL