DSP intro WIP

Author: daslu

src/signal_processing/intro.clj

@@ -5,6 +5,115 @@
                               :category    :clojure
                               :type        :post
                               :date        "2025-11-02"
-                              :tags        [:dsp :math :music]}}}
-(ns signal-processing.intro)
+                              :tags        [:dsp :math :music]
+                              :draft       true}}}
+(ns signal-processing.intro
+  (:require [scicloj.kindly.v4.kind :as kind]
+            [tech.v3.datatype :as dtype]
+            [tech.v3.datatype.functional :as dfn]
+            [clojure.math :as math]
+            [tablecloth.api :as tc]
+            [scicloj.tableplot.v1.plotly :as plotly]))
+
+
+(defn sine-samples [{:keys [sample-rate duration frequency amplitude]
+                     :or {amplitude 0.5}}]
+  (let [num-samples (int (* sample-rate duration))
+        ;; Generate samples as int16 reader
+        ]
+    (for [idx (range num-samples)]
+      (let [angle (* 2.0 Math/PI idx frequency (/ 1.0 sample-rate))]
+        (* amplitude (Math/sin angle))))))
+
+
+(defn sample-info [samples sample-rate]
+  (with-meta
+    {:samples samples
+     :sample-rate sample-rate}
+    {:kind/audio true}))
+
+
+(let [sample-rate 44100.0
+      A 440.0
+      E 659.25
+      wave (fn [freq]
+             (sine-samples
+              {:sample-rate sample-rate
+               :duration 3
+               :frequency freq
+               :amplitude 0.3}))]
+  (sample-info (map +
+                    (wave A)
+                    (wave E))
+               sample-rate))
+
+
+(require '[tech.v3.datatype :as dtype]
+         '[tech.v3.datatype.functional :as dfn]
+         '[clojure.math :as math]
+         '[tablecloth.api :as tc]
+         '[scicloj.tableplot.v1.plotly :as plotly])
+
+
+(def violin-components
+  [[:A4 440 3800]
+   [:A5 880 2750]
+   [:E6 1320 600]
+   [:A6 1760 700]
+   [:C#7 2200 1900]])
+
+(def sample-rate 44100.0)
+
+(def violin-components-dataset
+  (let [duration 10
+        num-samples (* duration sample-rate)
+        time (dtype/make-reader :float32
+                                num-samples
+                                (/ idx sample-rate))]
+    (->> violin-components
+         (map (fn [[label freq amp]]
+                [label (-> time
+                           (dfn/* (* 2 Math/PI freq))
+                           dfn/sin
+                           (dfn/* amp))]))
+         (into {:time time})
+         tc/dataset)))
+
+
+violin-components-dataset
+
+
+(-> violin-components-dataset
+    (tc/head 1000)
+    (plotly/layer-line {:=x :time
+                        :=y :A4}))
+
+
+(-> violin-components-dataset
+    (tc/head 100)
+    (tc/pivot->longer (complement #{:time}))
+    (plotly/layer-line {:=x :time
+                        :=y :$value
+                        :=color :$column}))
+
+(def violin-dataset
+  (-> violin-components-dataset
+      (tc/add-column :violin
+                     #(dfn/+ (:A4 %)
+                             (:A5 %)
+                             (:E6 %)
+                             (:A6 %)
+                             (:C#7 %)))))
+
+
+(-> violin-dataset
+    (tc/head 400)
+    (plotly/layer-line {:=x :time
+                        :=y :violin}))
+
+
+(sample-info (dfn// (:violin violin-dataset)
+                    7000.0)
+             sample-rate)
+