topic Re: Move Selected Columns() with list parameter in Discussions

Move Selected Columns() with list parameter

john_madden — Sun, 27 Jan 2019 19:09:01 GMT

If I have a table with five columns:

Column 5	Column 3	Column 2	Column 1	Column 4
data	data	data	data	data

and I execute this:

dt = Current Data Table();
dt << Move Selected Columns({"Column 1", "Column 2", "Column 3", "Column 4", "Column 5"}, To first)

then I get this:

Column 1	Column 2	Column 3	Column 4	Column 5
data	data	data	data	data

But if I execute this:

dt= Current Data Table();
list = {"Column 1", "Column 2", "Column 3", "Column 4", "Column 5"};
dt << Move Selected Columns( list, To first);

it fails with an "Unrecognized key word" error.

I need to be able to parameterize the column list, as in the second version. How can I make something like the second version work?

Re: Move Selected Columns() with list parameter

pmroz — Sun, 27 Jan 2019 20:37:42 GMT

I tried various flavors of as list(), listeval(), expr, evalexpr(), etc. to no avail. Had to resort to eval(parse()):

dt = current data table();

alist = {"Column 4", "Column 3", "Column 2", "Column 1"};
clist = char(alist);

col_expr = evalinsert("dt << move selected columns(^clist^, to first)");

eval(parse(col_expr));

Re: Move Selected Columns() with list parameter

john_madden — Sun, 27 Jan 2019 21:25:44 GMT

Thanks, that works for me!

Re: Move Selected Columns() with list parameter

gzmorgan0 — Mon, 28 Jan 2019 20:01:51 GMT

This is just an alternate method, and FYI.

You can also do this with expressions. Eval Expr() replaces each Expr() with its value (name expression), and the external Eval() function, executes the command.

dt= Current Data Table();
list = {"Column 1", "Column 2", "Column 3", "Column 4", "Column 5"};
Eval( Eval Expr(dt << Move Selected Columns( Expr(list), To first)) );

Re: Move Selected Columns() with list parameter

Audrey_Shull — Tue, 05 Feb 2019 18:35:13 GMT

I'm glad to hear a workaround has been found. In the meantime, we reported this issue to development, and JMP 15 (available later this year) has been updated so that the evaluation will happen automatically. Thanks!