topic Re: JLS- Divide Column by a Value in Discussions

JLS- Divide Column by a Value

natalie_ — Thu, 07 Jan 2016 21:41:59 GMT

Hi again,

I am writing some script which opens several csv files and joins them; it is working well!

In one column, I'd like to divide the values of another column by a value. I just can't figure it out. I can do it on the formula editor though, but I don't believe I can use that syntax while scripting.

dt << New Column("."); //just to create a blank column

dt << New Column("Id(A/mm)");

col = Column("Id(A/mm)");

col << Set Formula(Column("Id(A)")/Wg);

col << EvalFormula;

[code/]

Re: JLS- Divide Column by a Value

David_Burnham — Thu, 07 Jan 2016 22:46:24 GMT

something like this maybe:

someNumbers = 1::10;

New Table("demo",

Add Rows(10),

New Column("Sequence", numeric, continuous, <<Set Values(someNumbers) )

);

col = New Column(".", numeric, continuous);

valueToDivideBy = 2;

col << Set Formula(:Sequence/valueToDivideBy);

// or ...

col = New Column("..", numeric, continuous);

col << Set Formula( AsColumn("Sequence")/2);

Re: JLS- Divide Column by a Value

txnelson — Fri, 08 Jan 2016 01:44:04 GMT

There is an issue with the first solution provided by David. While the code will work, the formula created is:

:Sequence/valueToDivideBy

Since "valueToDivideBy" is a scalar memory variable, that will go away once the JMP session is closed, or could change value during the course of the day's processing, the calculated value of "col" could become invalid or incorrect. The second version of the formula would be preferred. However, if you want to use the structure of the first solution, you could do a couple of things:

1. Change the Se Formula to:

col << Set Formula(Eval(Parse(":Sequence/"||char(valueToDivideBy)));

2. Convert the formula to static values once the formula has been applied. To do this, add the following line after the the col << Set Formula line

col << delete property("formula");

Re: JLS- Divide Column by a Value

David_Burnham — Fri, 08 Jan 2016 08:20:13 GMT

yes, well spotted. thanks

Re: JLS- Divide Column by a Value

natalie_ — Fri, 08 Jan 2016 16:17:16 GMT

I chose to use David's second method. I think I understand why his first method has an issue, but I was unable to make your suggested changes. As I run the script, I can make all the new column, but the formulas are not working.

col= new column("."); //add blank column

col=New Column("Id(A/mm)",numeric,continuous);

col<<Set Formula(Eval,Parse(":Id(A)/"||Char(Wg)));

col<<delete property(":Id(A)/"||Char(Wg));