i have written a script, which copies every nth row of a worksheet into a new worksheet to get rid of unnecessary data. It works very well until not the 31th row in the new worksheet is reached. I use the command:

copy -b N Data1_A Data2_A -b i -e i

N, i: numbers form 1 to ....

If i is smaller than 30 the command works very well, if i is 31 or bigger, it produces a command error, although more than 40 rows exist in Data2. What can I do?

Thanks Ralph

I have seen a problem running Worksheet scripts assigning new data to empty cells where there is no data non of the columns. I have solved this by assigning %H_B = % H_A/0; which does not gives any data except for the �-� showing non-valid data. In the example above be sure that column A has data for all rows. (%H contains the Name of the current Worksheet window)

I hope this can help until we hopefully get a response from tech support that can explain the behaviour.

get Data1_A -e nn1; // nn1=number of rows in Data1
for(i=1;i>0;i++) {
N=2*i; if(N>nn1) break; // stop if we've exhausted Data1
get Data2_A -e nn2; // nn2=number of rows already in Data2_A
set Data2 -er nn2+1; // add a row to Data2
copy -b N Data1_A Data2_A -b i -e i;
copy -b N Data1_B Data2_B -b i -e i;
};

I prefer the simpler expression Data2_A[i]=Data1_A[N] for copying values one at a time, but that's probably just a matter of taste.

As Mike says, you need to use the get and set commands. When columns in a worksheet are not filled with data, the get datasetName -e end command will set the variable, end, to 0. By using the set datasetName -e 50 command, you will fill the dataset with 50 rows of missing values. (You can think of this as 50 placeholders.) This is also what HelgeSteen does when he uses the notation, %H_B = % H_A/0;

In other words, you want to first set the number of rows available before copying data into the column. And you do this with the set command.

For example:

If you wanted to copy rows 10-50 of data1_a to data2_a, then you would use the following script:

set data2_a -e 41;
copy -b 10 data1_a data2_a -b 1 -e 41;

it seems that the problem is more sophisticated.
The copy -b works in 31st row when this row exists and is manually created by insert. In the script I wrote a worksheet is created by

window -n wks %L;
window -a %L;
worksheet -a c;

(%L worksheet name). This worksheet initially contains 40 rows. When copy -b is executed now on row number 31 it fails.
So, is there a way to insert a number of rows into a worksheet by Lab Talk?
Maybe this helps.

Thanks Ralph