Update dft

src/HahnWitjesZettel6.4.jl

@@ -1,5 +1,13 @@
+using Pkg
+Pkg.add("Plots")
+
 using Plots
 
+"""
+Start the program with
+julia -i HahnWitjesZettel6.4.jl
+"""
+
 # https://en.wikipedia.org/wiki/Discrete_Fourier_transform#Definition
 function dft(x)
     N = length(x)
@@ -23,13 +31,13 @@ function evaluate_coefficients(x, coeffs)
 end
 
 function f(n)
-    xs = (0:n-1) ./ n
+    xs = (0:n-1) ./ n # Exclude the last one
     [x < 1/2 ? (x, x) : (x, 1 - x) for x in xs]
 end
 
 function main()
     ns = [3, 6, 10, 15, 20, 25]
-    plt = plot(layout = (length(ns), 2), size = (1000, 1000))
+    plt = plot(layout = (length(ns), 2), size = (1200, 1000))
 
     for (row, n) in enumerate(ns)
         points = f(n)
@@ -45,7 +53,7 @@ function main()
             plt[row, 1],
             xfine,
             real.(poly),
-            title = "n = $n (real part)",
+            title = "n = $n (Realteil)",
             legend = false
         )
         scatter!(
@@ -57,14 +65,13 @@ function main()
             plt[row, 2],
             xfine,
             imag.(poly),
-            title = "n = $n (imag part)",
+            title = "n = $n (Imaginaerteil)",
             legend = false
         )
     end
 
-    gui(plt)
+    savefig("HahnWitjesZettel6.4.svg")
 end
 
 main()
-
-
+gui()

src/Project.toml

@@ -0,0 +1,2 @@
+[deps]
+Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"