reading ascii image pixel by pixel

[firetry]

Hi everybody

I am currently building a model for the estimation of fog input into a tropical forest. Therefore I need to read some spatial data in the .asc or .txt format and to process them pixel by pixel.
To get a bit into it, I tried it with implicit reading and writing on a 2 rows/3columns samplefile, but it wont work:

The samplefile is files.txt:
123
456

The way I tried it is:

program try

implicit none
integer :: i,j
character*1 edgy(2,3)

open (3, file="test.txt",Access='direct',recl=3)
open(2,file="files.txt",Access='direct',recl=3)
do 1, i=1,2
read (2,rec=i) (edgy(i,j),j=1,3)
write(3,rec=i) (edgy(i,j),j=1,3)
1 continue
close(2)
close(3)
end
The output in test.txt is only:

123
4

Any idea what I am doing wrong? Hard to find more on this processing in the net

Greets and Thanks,
Frank

[DavidWhite]

Quoting - firetry

Hi everybody

I am currently building a model for the estimation of fog input into a tropical forest. Therefore I need to read some spatial data in the .asc or .txt format and to process them pixel by pixel.
To get a bit into it, I tried it with implicit reading and writing on a 2 rows/3columns samplefile, but it wont work:

The samplefile is files.txt:
123
456

The way I tried it is:

program try

implicit none
integer :: i,j
character*1 edgy(2,3)

open (3, file="test.txt",Access='direct',recl=3)
open(2,file="files.txt",Access='direct',recl=3)
do 1, i=1,2
read (2,rec=i) (edgy(i,j),j=1,3)
write(3,rec=i) (edgy(i,j),j=1,3)
1 continue
close(2)
close(3)
end
The output in test.txt is only:

123
4

Any idea what I am doing wrong? Hard to find more on this processing in the net

Greets and Thanks,
Frank

Frank,

In your input, 123 is recognised as a single integer, and so is read into the first element of the array. you would need to add some format statements, giving the format of the input as 3i1, so that three separate integers 1,2,3 are read.

David

[Les_Neilson]

Is files.txt really direct access ?

If it is a sequential formatted text file itwould have "hidden" information (maybe header and trailer lengths or CR, LF characters)
I created a files.txt using notepad and ran your program and got exactly the output you describe.
The contents of that files.txt (in HEX) is 3132 330d 0a34 3536 0d0a
the 0d and 0a are CR/LF

Also may I suggest you define edgy as (3,2) and change edgy(i,j) to edgy(j,i) this will keep the data contiguouswhich helps in debugging especially if the actual sizes are large.

Les