topic Re: Count in a script in Discussions

Count in a script

Dennis1 — Tue, 26 Nov 2019 23:30:19 GMT

Hi,
I need some assistance with adding a count in a script to a new column where it counts the number of rows from n=1 to n= m (based on size of size of text file). Any thoughts / comments greatly appreciated.
Cheers,
Dennis

Re: Count in a script

txnelson — Wed, 27 Nov 2019 01:16:59 GMT

I am not sure if I really understand what you want, but if it is a simple sequence number you can easily do that multiple ways.

First, interactively. Once you create the new column, simply go to the Col Info for the new column and click on the Missing/Empty down arrow and select "Sequence Data". I will place into the new column a number from 1 to n.

Second, you can use a formula in a new column. Just create the new column, anduse the below formula to generate a sequence number for each row.

Row()

Re: Count in a script

Dennis1 — Wed, 27 Nov 2019 01:28:27 GMT

Hi,
Sorry about not being clear. Is there a way to add the count into a script?

Re: Count in a script

txnelson — Wed, 27 Nov 2019 01:39:31 GMT

Are either of these examples any help?

dt = current data table();

dt << new column( "RowNum", format( Row() ) );

dt << new column( "Counter using a For Loop" );
For( i=1, i<= N Rows(dt), i++,
	dt:Counter using a For Loop[i] = i;
);

Re: Count in a script

Dennis1 — Wed, 27 Nov 2019 06:04:27 GMT

Hi,
Thanks for the suggestion.
I am trying to get it to work, but it still does not generation a column
with number 1,2,3,....etc.
I will keep trying.

Cheers,

Re: Count in a script

txnelson — Wed, 27 Nov 2019 06:13:17 GMT

The examples I listed before are assuming that you were adding the columns to an already existing data table. If you are creating a data table from scratch and it does not have any rows defined for it, one needs to use the

dt << add rows(100);

to create empty rows, before one can place values in the cells.

Here is a complete example

names default to here(1);
dt=new table("Example");

dt << new column( "Counter using a For Loop" );
dt << add rows(100); 
For( i=1, i<= N Rows(dt), i++,
	dt:Counter using a For Loop[i] = i;
);

Re: Count in a script

Dennis1 — Wed, 27 Nov 2019 07:36:27 GMT

Thank you, that's awesome! I got it to work.

I just have one more question. If I don't know the exact number of rows
generated (due to text file size variation), is there a way to read the
text file and have the exact rows for the counter?

Re: Count in a script

Dennis1 — Wed, 27 Nov 2019 08:57:33 GMT

Thanks for that, works great!
Much appreciated.
Cheers,