Hi there, Well, two things: 1- print procedure needs to have the FORMAT keyword so that you can "display" all the digits that you would like to see on the screen, for example: print, textfile, , format='(f10.2)' 2- You need to declare the input numbers as double, before using any function on them, like double(). In other words, in the text file, the numbers should have a D at the end: 1234567.26D Then, a double precision memory address will be reserved for that number, ie. a 4 byte number. Otherwise, without the D, the number is considered single precision, ie. only 6 or 7 significant digits are used. In double precision, approx. 14 significant digits are used. I hope this helps. Please, take a look at the IDL Help table on "IDL Data Types". Cheers, Fernando

Hi Fernando, thank you for your reply. I tried with your advice... I added the D in my inputfile and used the FORMAT keyword with Format='(F10.2,5X,F10.2)'. My inputfile: 1234567.26D 1234567.72D 1098765.27D 1098765.29D 5394310.26D 3572300.72D 5393548.27D 3572694.29D IDL prints: 1234567.25 1234567.75 1098765.25 1098765.25 5394310.50 3572300.75 5393548.50 3572694.25 All digits are displayed, but i want my input-elements without rounding. Hope you have an idea! Cheers, TDN

Hi there, What happens is that read_ascii(file) only reads single precision float numbers. You will need instead to do something like: file='C:\path\to\datafile.txt' data = DBLARR(2,4) ; create first an array to keep the double precision numbers. openr, lun, file, /GET_LUN READF, lun, data print, data, format='(f10.2,1x,f10.2)' free_lun, lun Cheers, Fernando

Hi, thank you very much. It works now! Cheers, tdn