We implement here a program that reads data from a text file
bottle.dat and writes a png-image file. The program
consists of a main program and a module (io) which contains the
actual read and write routines. Your task is to implement the reading
of the data, i.e. the function read_field.
The text file contains a header line: “# nx ny”, followed by lines
representing the rows of the field. Read first the header line, allocate
then enough space for the field array and finally read the actual data.
A skeleton code is provided in io.F90. Once you have completed
the implementation, you can build the full program (io) with the provided
Makefile by executing
$ make
The program can then be executes as
$ ./io
The .png output file can be investigated with a image viewer program (e.g. eog in Linux).