How to lookup the earliest date, then select the related value and pinpoint that (like $ in Excel)

[Fleurdc]

Hi everbody! 

For my project i need to graph prices of different products in an indexed manner (so every line starting from 100). In order to do so, I need to divide each price of each product by the earliest price available for that product. 

Then, preferably, i would like to have that if i slice the first date available for a product, that it will take the new first date as the earliest price.

So, my question is, does anybody knows a DAX formula with which i can look for the first date available for each supplier/product combination, then select the price corresponding to this date+supplier+product? And then also pin point that related price (as like $ in Excel) so i can divide all other prices by that earliest price? (In that way i calculate the index)

My dataset looks like follows:

And i would like to show my graph as follows:

Would be very helpful! Thank you in advance! 

Kind regards,

Fleur de Clercq

[danextian]

Hi @Fleurdc ,

This is how you can get the earliest price:

Earliest Price by Product by Supplier =
VAR __EARLIEST_DATE =
    CALCULATE (
        MIN ( 'Table'[Date] ),
        ALLEXCEPT ( 'Table', 'Table'[Supplier], 'Table'[Product] )
    )
RETURN
    CALCULATE (
        MAX ( 'Table'[Price] ),
        FILTER (
            ALL ( 'Table' ),
            'Table'[Supplier] = EARLIER ( 'Table'[Supplier] )
                && 'Table'[Product] = EARLIER ( 'Table'[Product] )
                && 'Table'[Date] = __EARLIEST_DATE
        )
    )

As to the related price, please indicate how to achieve this. Also, moving forward, please post a sample data that we can copy-paste (not an image).