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Re: how to find number of lines in an ASCII file? [message #12541 is a reply to message #12536]

Thu, 20 August 1998 00:00

mallors
Messages: 76
Registered: November 1997

Member

In article <6rdfig$756@post.gsfc.nasa.gov>,
jyli@redback.gsfc.nasa.gov (Jason Li) writes:
> Hi,
>
> I have an ASCII text file that contains data in a nice tabular form,
>
> 0 28660 1827.1 72.7705 -158.8828 3388.0 22.3846 10.8545
> 1 28661 1827.7 72.7701 -158.8752 3391.0 21.1213 10.6029
> 2 28662 1828.3 72.7698 -158.8677 3394.0 19.8743 10.3546
> .
> .
> .
>
> I want to read them all and save into an array:
> data[8, numberOfLines]. But
> I don't know numberOfLines in the file before hand.
> What is the most efficient way to find that out?

Here is yet another method:

IDL does not need to know the number of lines in the file. It
will dynamically increase the array for you. Assuming you know
how many columns are in the file, I would read it into an array of
structures as follows:

data = {c1: 0L, c2: 0L, c3: 0.0, ..., c8: 0.0}
data_in = data

OPENR, FL, file, /GET_LUN

READF, FL, data
WHILE (NOT EOF (FL)) DO BEGIN
READF, FL, data_in
data = [data, data_in]
ENDWHILE
FREE_LUN, FL

Now data is an array of structures. The array length
is the number of lines in the column. One caveat: this
method won't work if any of the columns are STRING data.

--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~
Robert S. Mallozzi 256-544-0887
Mail Code ES 84
Work: http://crazyhorse.msfc.nasa.gov/ Marshall Space Flight Center
Play: http://cspar.uah.edu/~mallozzir/ Huntsville, AL 35812
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~

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[Message index]

		Re: how to find number of lines in an ASCII file? By: Paul Krummel on Fri, 21 August 1998 00:00
		Re: how to find number of lines in an ASCII file? By: Martin Schultz on Thu, 20 August 1998 00:00
		Re: how to find number of lines in an ASCII file? By: mallors on Thu, 20 August 1998 00:00
		Re: how to find number of lines in an ASCII file? By: Paul Krummel on Thu, 20 August 1998 00:00
		Re: how to find number of lines in an ASCII file? By: Martin Schultz on Wed, 19 August 1998 00:00
		Re: how to find number of lines in an ASCII file? By: Kevin Ivory on Wed, 19 August 1998 00:00
		Re: how to find number of lines in an ASCII file? By: meron on Wed, 19 August 1998 00:00

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