Tableau Calculated Field - across multiple measures

Question

I am trying to take the minimum of a set of fields, excluding 0's. I am fairly new to using calculated fields in Tableau.

I have been able to chain the min function like so:
MIN(MIN(MIN([a],[b]), [c]), [d]) etc...

However, I can not figure out a way to filter out the 0s for every one of my measures. I tried something with REGEXP_REPLACE. I also tried to set a larger IF THEN for the values with something like:

IF [a] > 0 THEN [a]  
IF [b] > 0 THEN [b]

So that the new values would be nulled out. But, this didn't work either due to my need to chain all of them in this one calculated field. What is a functional way to calculate something like this? Assuming I can not modify the data outside of Tableau, what is a way to handle modifying multiple fields like this?

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Desired Result:
(Pseudo Code)

given that a,b,c,d,e = 15,0,10,0,25  
Min_No0([a],[b],[c],[d],[e],...) = 10

Answer 1

Okay, I was able to do the following successfully:

MIN(MIN(IF [a] = 0 THEN 9999999 ELSE [a] END, 
IF [b] = 0 THEN 9999999 ELSE [b] END),
IF [c] = 0 THEN 9999999 ELSE [c] END)

By chaining min and by having an if statement within the min function. This isn't the best way I am sure, but it worked.

Answer 2

Here is a solution that looks for the MIN() between columns [a] [b] and [c], excluding and values that are zero.

MIN(MIN(IF [a] !=0 THEN [a]
        ELSEIF [b] !=0 THEN [b]
        ELSEIF [c] !=0 THEN [c]
        END,

    IF [b] !=0 THEN [b]
        ELSEIF [c] !=0 THEN [c]
        ELSEIF [a] !=0 THEN [a]
        END),

    IF [c] !=0 THEN [c]
        ELSEIF [a] !=0 THEN [a]
        ELSEIF [b] !=0 THEN [b]
        END)

The inner MIN() is compares [a] and [b]. If either of these numbers is zero, it substitutes another number, provided that number is also not equal to zero. The outer MIN() compares [c] to the smaller number from the inner MIN().

If [a], [b], and [c] are all equal to zero, the result will be 'Null' of course.