Change positives to negatives and the other way around

[VivianaTudora]

Hi all, 

I have a column with both negative and positive values and I need to have them changed to the opposite. The positives are actually negative and negatives are positive. I know I can change them all to absolute, but can't think how to also store the positives as negative?

Hope this makes sense, no idea why the values are stored like this in the database. 

Thank you!

[Anonymous]

I don't like creating a new custom column to multiply the old value by -1, so I solved the problem by transforming the value in place using a trivial custom function "Negate"

let
    Negate = ( x ) => try -1 * x otherwise null,

    Source = Table.FromRecords({
        [CustomerID = 1, Name = "Bob",  Value = 305 ],
        [CustomerID = 2, Name = "Jim",  Value = -100 ],
        [CustomerID = 3, Name = "Paul", Value = 0.305 ],
        [CustomerID = 4, Name = "Pau2", Value = "0.305" ],
        [CustomerID = 5, Name = "Pau3", Value = null ]
    }),

    Negated = Table.TransformColumns(Source, {{"Value", Negate}})

in
    Negated

[Zubair_Muhammad · Accepted solution]

@VivianaTudora

You can simply multiply them with -1.

Isn't it?

[VivianaTudora]

You're right! Didn't realise it's so simple. 

Thanks a lot! 🙂