Slope calculation given a date axis

[RMDNA]

Hi all,

I have a table of sales over time (number as value, date as axis), and I'm attempting to make a calculation that displays the slope for the value, given the start and end points are for whatever criteria is currently selected.

I have an initial and ending value, and % change between the two, but can't figure out how to translate that into slope given a date axis.

[v-yuta-msft]

Hi RMDNA,

Which kind of slope you want to achieve? Maybe some custom chart can meet your requirement. In addtion, could you share some sample data for further analysis?

Regards,

Jimmy Tao

[jfieck123]

I am wondering about this one as well.  I have not been able to find a nice "SLOPE" function in the DAX library.  

I did find a custome function that works when the x-axis are some kind of number in integrer format.  But my x-axis is a month-day/year.

I am looking for any tips or tricks on this one...

This would be a sample of the data set:

dt_RPTMONTH_INC                 Incoming Incidents
11/1/2016 0:00                        9256
12/1/2016 0:00                       8350
1/1/2017 0:00                         8905
2/1/2017 0:00                         8973
3/1/2017 0:00                             9864
4/1/2017 0:00                          8495
5/1/2017 0:00                          9533
6/1/2017 0:00                          9227
7/1/2017 0:00                          8341
8/1/2017 0:00                          9295
9/1/2017 0:00                           8923
10/1/2017 0:00                        8939
11/1/2017 0:00                       8213
12/1/2017 0:00                6902
1/1/2018 0:00                          7965
2/1/2018 0:00               8042
3/1/2018 0:00                        8906
4/1/2018 0:00                       8758
5/1/2018 0:00                      8965
6/1/2018 0:00                      8382
7/1/2018 0:00 8656
8/1/2018 0:00 8901
9/1/2018 0:00 8101
10/1/2018 0:00 8439
11/1/2018 0:00 2952

Here is the function I'm using but it's not calculating the slope correctly being the Known[X] values are a date. 

QRC Inc Slope Test =

VAR Known =

FILTER (

SELECTCOLUMNS (

            DATESINPERIOD(

                PBI_INCOMING_16_MONTHS[dt_RPTMONTH_INC],

                LASTDATE (PARALLELPERIOD (PBI_INCOMING_16_MONTHS[dt_RPTMONTH_INC], -1 * [QRC Month Offset], MONTH)),

                -9,

                MONTH

            ),

"Known[X]", PBI_INCOMING_16_MONTHS[dt_RPTMONTH_INC],

"Known[Y]", PBI_INCOMING_16_MONTHS[Incoming Incidents]

),

AND (

NOT ( ISBLANK ( Known[X] ) ),

NOT ( ISBLANK ( Known[Y] ) )

)

)

VAR Count_Items =

COUNTROWS ( Known )

VAR Sum_X =

SUMX ( Known, Known[X] )

VAR Sum_X2 =

SUMX ( Known, Known[X] ^ 2 )

VAR Sum_Y =

SUMX ( Known, Known[Y] )

VAR Sum_XY =

SUMX ( Known, Known[X] * Known[Y] )

VAR Average_X =

AVERAGEX ( Known, Known[X] )

VAR Average_Y =

AVERAGEX ( Known, Known[Y] )

VAR Slope =

DIVIDE (

Count_Items * Sum_XY - Sum_X * Sum_Y,

Count_Items * Sum_X2 - Sum_X ^ 2

)

RETURN

Slope