# Graph of aliasing frequencies
# Triangle wave

# Set terminal
set terminal svg enhanced size 300 200 fs 10
set samples 1001  # high quality
set border 31 linewidth .3 # thin border

set output "aliasing-folding.svg"

# Ranges
set xrange [-.2:2.2] # 2 cycles, with room for labels
set xtics  ( \
     "0"     0,                                        \
   "fs/4"  .25,   "fs/2"  .5,  "3fs/4"  .75,   "fs" 1, \
  "5fs/4" 1.25,  "3fs/2" 1.5,  "7fs/4" 1.75,  "2fs" 2  \
           ) # Key feature (fold) is at .5; add .25 for reference
set yrange [-.1:1.1] # Slight headroom from max of 1
set ytics ( \
   "0"  0,  "fs/4"  .5,  "fs/2" 1  \
          ) # Corresponding y values

# Zero axes and grid as guidelines, no key (self-explanatory)
set zeroaxis
set grid
unset key

###########################
# Define and plot function
###########################

tri(x) = acos(cos(2*pi*x))/pi # normalized triangle wave

plot tri(x)