added octave_ratio to expand harmonics

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: hrep
 Title: Harmony Representations
-Version: 0.16.1
+Version: 0.20.0
 Authors@R: person("Peter", "Harrison", email = "pmc.harrison@gmail.com", role = c("aut", "cre"))
 Description: This package provides utilities for representing and manipulating 
     chord sequences for perceptually informed harmony modelling.
@@ -18,7 +18,7 @@ Suggests:
     testthat (>= 2.1.0),
     covr (>= 3.2.0),
     ggplot2 (>= 3.0.0)
-RoxygenNote: 7.2.3
+RoxygenNote: 7.3.1
 Imports: 
     plyr (>= 1.8.4),
     Rdpack (>= 0.9.0),

NEWS.md

@@ -1,3 +1,11 @@
+# hrep 0.20.0
+
+# hrep 0.19.0
+
+# hrep 0.18.0
+
+# hrep 0.17.0
+
 # hrep 0.16.1
 
 - Remove unnecessary info messages.

R/expand-harmonics.R

@@ -13,7 +13,7 @@
 #' Number of harmonics (including the fundamental) to which
 #' each tone should be expanded.
 #'
-#' @param roll_off (Numeric scalar) Parametrises the amount of amplitude roll-off
+#' @param roll_off_dB (Numeric scalar) Parametrises the amount of amplitude roll-off
 #' in the harmonics, with greater values corresponding to higher roll-off.
 #'
 #' @param digits
@@ -22,30 +22,35 @@
 #' @param label_harmonics
 #' If TRUE, then the harmonics in the resulting spectrum are labelled with their harmonic numbers.
 #'
+#' @param pseudo_octave
+#' The octave ratio for stretching and compressing harmonics, defaults to 2.0.
+#'
 #' @rdname expand_harmonics
 #'
 #' @inheritParams collapse_summing_amplitudes
 #' @export
 expand_harmonics <- function(x,
                              num_harmonics = 11L,
-                             roll_off = 1,
+                             roll_off_dB = 1,
                              digits = 6,
                              label_harmonics = FALSE,
-                             coherent = FALSE) {
+                             coherent = FALSE,
+                             pseudo_octave = 2.0) {
   UseMethod("expand_harmonics")
 }
 
 #' @rdname expand_harmonics
 #' @export
 expand_harmonics.sparse_fr_spectrum <- function(x,
                                                 num_harmonics = 11L,
-                                                roll_off = 1,
+                                                roll_off_dB = 1,
                                                 digits = 6,
                                                 label_harmonics = FALSE,
-                                                coherent = FALSE) {
+                                                coherent = FALSE,
+                                                pseudo_octave = 2.0) {
   expand_harmonics(sparse_pi_spectrum(x),
                    num_harmonics = num_harmonics,
-                   roll_off = roll_off,
+                   roll_off_dB = roll_off_dB,
                    digits = digits,
                    label_harmonics = label_harmonics,
                    coherent = coherent) %>%
@@ -56,18 +61,20 @@ expand_harmonics.sparse_fr_spectrum <- function(x,
 #' @export
 expand_harmonics.sparse_pi_spectrum <- function(x,
                                                 num_harmonics = 11L,
-                                                roll_off = 1,
+                                                roll_off_dB = 1,
                                                 digits = 6,
                                                 label_harmonics = FALSE,
-                                                coherent = FALSE) {
-  template <- pi_harmonic_template(num_harmonics, roll_off)
+                                                coherent = FALSE,
+                                                pseudo_octave = 2.0) {
   purrr::map2(pitch(x), amp(x),
               function(pitch, amp) {
+                n  <- seq_len(num_harmonics)
+                f0 <- midi_to_freq(pitch)
                 df <- data.frame(
-                  x = pitch + template$interval,
-                  y = amp * template$amplitude
+                  x = freq_to_midi(f0 * pseudo_octave ^ log2(n)),
+                  y = 1 * 10 ^ ( -roll_off_dB * log2(n) / 20)
                 )
-                if (label_harmonics) df$labels <- seq_along(template$interval)
+                if (label_harmonics) df$labels <- seq_along(df$x)
                 df
               }) %>%
     collapse_summing_amplitudes(digits = digits, coherent = coherent) %>%
@@ -78,19 +85,14 @@ expand_harmonics.sparse_pi_spectrum <- function(x,
 #' @export
 expand_harmonics.pi_chord <- function(x,
                                       num_harmonics = 11L,
-                                      roll_off = 1,
+                                      roll_off_dB = 1,
                                       digits = 6,
                                       label_harmonics = FALSE,
-                                      coherent = FALSE) {
+                                      coherent = FALSE,
+                                      pseudo_octave = 2.0) {
   sparse_pi_spectrum(x,
                      num_harmonics = num_harmonics,
-                     roll_off = roll_off,
+                     roll_off_dB = roll_off_dB,
                      digits = digits,
                      label_harmonics = label_harmonics)
 }
-
-pi_harmonic_template <- function(num_harmonics, roll_off, digits = 6) {
-  tibble::tibble(n = seq_len(num_harmonics),
-                 interval = 12 * log(.data$n, base = 2),
-                 amplitude = 1 / (.data$n ^ roll_off))
-}

R/smooth-pc-spectrum.R

@@ -75,7 +75,7 @@ smooth_pc_spectrum <- function(
   ...,
   sigma = 6.83,
   num_harmonics = 11L,
-  roll_off = 1,
+  roll_off_dB = 1,
   coherent = FALSE
 ) {
   UseMethod("smooth_pc_spectrum")
@@ -88,12 +88,12 @@ smooth_pc_spectrum.default <- function(
   ...,
   sigma = 6.83,
   num_harmonics = 11L,
-  roll_off = 1,
+  roll_off_dB = 1,
   coherent = FALSE
 ) {
   smooth_pc_spectrum(sparse_pc_spectrum(x,
                                         num_harmonics = num_harmonics,
-                                        roll_off = roll_off,
+                                        roll_off_dB = roll_off_dB,
                                         coherent = coherent),
                      sigma = sigma,
                      coherent = coherent,

R/smooth-pi-spectrum.R

@@ -79,12 +79,12 @@ smooth_pi_spectrum <- function(x, sigma = 6.83, ...) {
 smooth_pi_spectrum.default <- function(x,
                                        sigma = 6.83,
                                        num_harmonics = 11L,
-                                       roll_off = 1,
+                                       roll_off_dB = 1,
                                        coherent = FALSE,
                                        ...) {
   smooth_pi_spectrum(sparse_pi_spectrum(x,
                                         num_harmonics = num_harmonics,
-                                        roll_off = roll_off,
+                                        roll_off_dB = roll_off_dB,
                                         coherent = coherent,
                                         ...),
                      sigma = sigma,

R/sparse-spectrum.R

@@ -78,14 +78,24 @@ set_labels.sparse_spectrum <- function(x, labels) {
 }
 
 #' @export
-plot.sparse_spectrum <- function(x, ggplot = FALSE, xlim = NULL, ...) {
+plot.sparse_spectrum <- function(x, cochlea=FALSE, ggplot = FALSE, xlim = NULL,
+                                 trans='identity', ...) {
   df <- as.data.frame(x)
+  if (cochlea) {
+    greenwood <- function(frequency) {
+      100 * (1 - (log10( frequency / 165.4 + 0.88 ) / 2.1))
+    }
+    df$x = greenwood(df$x)
+    x_label = 'Cochlea (%)'
+  } else {
+    x_label = x_lab(x)
+  }
   if (ggplot) {
     assert_installed("ggplot2")
       ggplot2::ggplot(df, ggplot2::aes_string(x = "x", xend = "x",
                                               y = 0, yend = "y")) +
       ggplot2::geom_segment() +
-      ggplot2::scale_x_continuous(x_lab(x), limits = xlim) +
+      ggplot2::scale_x_continuous(x_label, limits = xlim, transform=trans) +
       ggplot2::scale_y_continuous(y_lab(x))
   } else {
     n <- nrow(df)
@@ -95,7 +105,7 @@ plot.sparse_spectrum <- function(x, ggplot = FALSE, xlim = NULL, ...) {
       df2$x[I + 1:3] <- df$x[i]
       df2$y[I + 2L] <- df$y[i]
     }
-    plot(df2$x, df2$y, xlab = x_lab(x), ylab = y_lab(x),
+    plot(df2$x, df2$y, xlab = x_label, ylab = y_lab(x),
          type = "l", xlim = xlim, ...)
     if (!is.null(df$labels)) {
       for (i in seq_len(nrow(df))) {