Summary( ) Quesition

Question

Hello,

I have a problem when trying to call Summary(). I have a string containing the names of the columns that I want to create a summary table for, say var="height, weight". var may be different from data table to data table. I tried summary(sum(var)), but it didn't work. I wrote a loop that create a string var_expr=":height, :weight", but 
summary(substitute("sum(x)",expr(x),var_expr)) doesn't do the job either...

Maybe I need to use column reference, but first I don't want to create many global variables, second I don't know in a priori how many columns are there. Is there any easy way to get around this?

Thank you!

unknown · Answer

Purely for reference, here is some example code that performs the task using the Summarize command and Associative Arrays

unknown · Answer

Thank you! I think what I'm asking is answered by example 2. I'm writing a program which does the following job: suppose there are four columns in a data table, sex, height1, height2 and weight, the program will calculate sum(height1), sum(height2) and sum(weight) according to sex and then report sum(height1)/sum(wt) and sum(height2)/sum(wt) within each group (not for individual record, otherwise I think I can use the preselected role ). I'm trying to make the interface working for any data tables.

Now I'm trying to write it using both summary tables and matrices. Maybe the calculation can be done easily.

Thank you for your help!

unknown · Answer

Here are a couple of examples that may help:

// example 1
dt = Open("$SAMPLE_DATA/Big Class.jmp");
lst = {"height","weight"};
c1 = lst[1];
c2 = lst[2];
Summary( sum( Column(c1),Column(c2) ) )

// example 2
dt = Open("$SAMPLE_DATA/Big Class.jmp");
lst = {"height","weight"};
Summary( Sum( Eval(lst) ) )

Message was edited by: _Stig_