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+#Task solution - fast Fourier transform in fortran (using fftw3)#
+This repository contains the realization of the [second task](http://home.agh.edu.pl/~macwozni/fort/zadanie2.pdf) of the fortran programming language course at AGH in Cracov.  
+
+##Directory structure##
+
+    Makefile
+    README.md
+    make_results.sh
+    template.gnuplot
+    src/
+        fourier.F90
+        f1_dft.gnuplot
+        f1_original.gnuplot
+        f2_dft.gnuplot
+        f2_filtered.gnuplot 
+        f2_original.gnuplot
+    res/
+        f1_dft.txt
+        f1_original.txt
+        f2_dft.txt
+        f2_filtered.txt
+        f2_original.txt
+        f1_dft.png
+        f1_original.png
+        f2_dft.png
+        f2_filtered.png
+        f2_original.png
+
+###Makefile###
+This file contains recipes for building the fortran program and using to generate plots.   
+
+###src/###
+This directory contains the fortran source of the project, namely `fourier.f90` and gnuplot scripts for generating png plots.   
+
+###res/###
+This directory contains relevant plots of signals and frequency spectrums as required for the task.   
+
+##Building##
+As a prerequisite, fftw3, make and a fortran compiler, either gfortran or ifort, are required (didn't want to support proprietary compiler :c but had to). It is assumed, that include files for fftw3 are installed under `/usr/include`.   
+Run:   
+
+    $ make
+to build the program executable `fourier`.   
+The makefile checks which one of the 2 compilers is present and uses it. Alternatively, one can specify fortran compiler explicitly, e.g.:   
+
+    $ make FC=gfortran
+or:   
+
+    $ make FC=ifort
+
+##Running##
+The executable is `fourier`. It's mandatory first argument is name of the function to work with - 'f1' or 'f2'. If there're no other arguments - program prints datapoints for plotting the original function. If second argument is 'dft' - program prints datapoints of function's frequency spectrum as obtained from discrete fourier transform. If second argument is 'filtered' - program prints datapoints of filtered function (with frequency components of low values removed).   
+
+     $ ./fourier f2 filtered
+     0.0000000000000000         0.99737967443382569
+     1.5259021896696422E-005    0.99737363952277114
+     3.0518043793392844E-005    0.99736759544407216
+     4.5777065690089265E-005    0.99736154219778428
+     ⋮
+     0.99996948195620661         0.99739772416056849
+     0.99998474097810330         0.99739171675277982
+     1.0000000000000000         0.99738570017718042
+
+Text files and plots in `res/` can be regenerated by issuing
+
+    $ make pngs
+
+from the main project directory.   
+