iraf.net

I want to run the xt_csum and xt_lsum tasks which are in the xtools command. But when i put xtools on the command line it doesn't find the task, the same for xt_csum, and xt_lsum. What should i do?I am running iraf on a linux ubuntu feisty machine. I need to add the pixel values on a line from colum1 to colum2. I think the xt_lsum task is adecuate for this task.Any suggestions are welcome,

The XTOOLS are a library of SPP procedures, not actual tasks.To sum the pixels between two columns you can use something like the BLKAVG with option=sum, or just IMSTAT and then multiply the NPIX and MEAN values to get the sum. Another idea might be:[code:1:65a4b299ba]cl> listpix img[320:330,123] | fields STDIN 2 | average[/code:1:65a4b299ba]The 'sum' parameter in AVERAGE will be the sum of cols 320-330 on row 123.Cheers,
-Mike

Thanks, i'll try that.