Column formula using string varialble for column names

[#1]

I'm trying to create a bunch of new columns with formulas based on existing columns. New column statement is inside For loop and I want to use strings from a list as part column names.
My columns are from the table constructed by Summary function, thus they have "," in the names

InColumn = "qty_in, "||steps[step#];
OutColumn = "qty_out, "||steps[step#];
dt << New Column( Eval("% "||steps[step#]),
numeric,
continuous,
formula( Name(OutColumn) / Name(InColumn) * 100, 1));

steps is a list of strings {"a", "b", "c"} and step# is an integer of For cycle.

What I can not figure out is how to make my OutColumn and InColumn a "quoted string" so formula will work. I've tried Eval and Parse and As Name - nothing worked so far.

Any help will be greatly appreciated.

[#2]

Found the answer:

I had to use

As Column(Eval(InColumn))

in place of a column in the formula

[#3]

I have a similar problem and can't seem to find the
easiest combination of eval/parse/etc to solve it.
style="">  I’m
selecting from a table where the column
name is dynamic.





The following code works:






style="font-size: 10pt; font-family: "Courier New"; color: black;"> 
 tmp_matrix
style="font-size: 10pt; font-family: "Courier New"; color: navy;">=
style="font-size: 10pt; font-family: "Courier New"; color: black;">
dmt
style="font-size: 10pt; font-family: "Courier New"; color: navy;"><<
style="font-size: 10pt; font-family: "Courier New"; color: black;">
get rows where(
style="font-size: 10pt; font-family: "Courier New"; color: navy;">:
style="font-size: 10pt; font-family: "Courier New"; color: black;">Time
Period
style="font-size: 10pt; font-family: "Courier New"; color: navy;">==
style="font-size: 10pt; font-family: "Courier New"; color: black;">

style="font-size: 10pt; font-family: "Courier New"; color: purple;">"Current"
style="font-size: 10pt; font-family: "Courier New"; color: black;">




style="font-size: 10pt; line-height: 115%; font-family: "Courier New"; color: black;">
style="">                             

style="font-size: 10pt; line-height: 115%; font-family: "Courier New"; color: navy;">&
style="font-size: 10pt; line-height: 115%; font-family: "Courier New"; color: black;">
name(
style="font-size: 10pt; line-height: 115%; font-family: "Courier New"; color: purple;">"Angioedema"
style="font-size: 10pt; line-height: 115%; font-family: "Courier New"; color: black;">)
style="font-size: 10pt; line-height: 115%; font-family: "Courier New"; color: black;">

style="font-size: 10pt; line-height: 115%; font-family: "Courier New"; color: navy;">==
style="font-size: 10pt; line-height: 115%; font-family: "Courier New"; color: black;">

style="font-size: 10pt; line-height: 115%; font-family: "Courier New"; color: teal;">1
style="font-size: 10pt; line-height: 115%; font-family: "Courier New"; color: black;">)
style="font-size: 10pt; line-height: 115%; font-family: "Courier New"; color: navy;">;





The following code does not work:



style="font-size: 10pt; font-family: "Courier New"; color: black;">



style="font-size: 10pt; font-family: "Courier New"; color: black;"> 
 one_dme
style="font-size: 10pt; font-family: "Courier New"; color: navy;">=
style="font-size: 10pt; font-family: "Courier New"; color: black;">

style="font-size: 10pt; font-family: "Courier New"; color: purple;">"Angioedema"
style="font-size: 10pt; font-family: "Courier New"; color: navy;">;
style="font-size: 10pt; font-family: "Courier New"; color: black;">



style="font-size: 10pt; font-family: "Courier New"; color: black;"> 
 tmp_matrix
style="font-size: 10pt; font-family: "Courier New"; color: navy;">=
style="font-size: 10pt; font-family: "Courier New"; color: black;">
dmt
style="font-size: 10pt; font-family: "Courier New"; color: navy;"><<
style="font-size: 10pt; font-family: "Courier New"; color: black;">
get rows where(
style="font-size: 10pt; font-family: "Courier New"; color: navy;">:
style="font-size: 10pt; font-family: "Courier New"; color: black;">Time
Period
style="font-size: 10pt; font-family: "Courier New"; color: navy;">==
style="font-size: 10pt; font-family: "Courier New"; color: black;">

style="font-size: 10pt; font-family: "Courier New"; color: purple;">"Current"
style="font-size: 10pt; font-family: "Courier New"; color: black;">




style="font-size: 10pt; font-family: "Courier New"; color: black;">
style="">                             

style="font-size: 10pt; font-family: "Courier New"; color: navy;">&
style="font-size: 10pt; font-family: "Courier New"; color: black;">

style="font-size: 10pt; font-family: "Courier New"; color: rgb(0, 0, 221);">column
style="font-size: 10pt; font-family: "Courier New"; color: black;">(
style="font-size: 10pt; font-family: "Courier New"; color: rgb(0, 0, 221);">eval
style="font-size: 10pt; font-family: "Courier New"; color: black;">(
style="font-size: 10pt; font-family: "Courier New"; color: black;">one_dme))

style="font-size: 10pt; font-family: "Courier New"; color: navy;">==
style="font-size: 10pt; font-family: "Courier New"; color: black;">

style="font-size: 10pt; font-family: "Courier New"; color: teal;">1
style="font-size: 10pt; font-family: "Courier New"; color: black;">)
style="font-size: 10pt; font-family: "Courier New"; color: navy;">;
style="font-size: 10pt; font-family: "Courier New"; color: black;">



style="font-size: 10pt; font-family: "Courier New"; color: black;">


I could build an expression string and use eval(parse(string))
but I was wondering if there’s a
simpler way.





Thanks,


Peter



style="font-size: 10pt; font-family: "Courier New"; color: black;">

[#4]

I took the hint from the previous post and tried the following which seems to work (I simplified the condition):

one_dme = "Angioedema";
tmp_matrix = dmt << get rows where( As Column( Eval( one_dme ) ) == 1 );

[#5]

Thanks mpb. Now if I could learn to read I wouldn't have posted my question!

[#6]

I recently had some struggles with this issue and found that the only combination that worked for me was:

colExpr = Expr( Formula( As Column( Expr( inColumn ) ) ) );

Eval( Eval Expr( colExpr ) );

wait( 0 );

It all seems a bit clunky to me, but it was the only variant that I could get to work. I should also note that my As Column() statement was parsing another column from inside functions like Substitute(), Item(), and Word().