R/fft2d_visualizations.R

In hrvg/statisticalRoughness: Estimation of roughness exponents across scale for large areas

#' Visualizes values of a matrix
#' @param m a `matrix`
#' @param ply `logical`
#' @return if `ply = TRUE` returns a `plotly::ggploty()` object, if `FALSE` returns a `ggplot` object
#' @importFrom rlang .data
#' @export
#' @keywords fft2d_viz
view_matrix <- function(m, ply = TRUE){
	m <- m %>% t()
	m <- reshape2::melt(m)
	p <- ggplot2::ggplot(m, ggplot2::aes(x = .data$Var1, y = .data$Var2, fill = .data$value)) +
		ggplot2::geom_tile() + 
		ggplot2::scale_fill_viridis_c(na.value = "transparent") +
		ggplot2::scale_y_reverse() + 
		ggplot2::labs(x = "columns", y = "rows") +
		ggplot2::theme(legend.key.width = ggplot2::unit(1, "in")) +
		ggpubr::theme_pubr() +
		ggplot2::coord_fixed(ratio = 1)
	if(ply) {
		return(plotly::ggplotly(p))
	} else {
		return(p)
	}
}

#' Transforms matrix for be used by `rayshader`.
#' @param m a `matrix`
#' @return a `matrix`
#' @export
#' @keywords fft2d_viz
matrix_for_rayshader <- function(m){
	m <- t(m)
	return(m)
}

#' Plot a radial Fourier spectrum
#' @param binned_power_spectrum `matrix`, a binned spectrum from `bin()`
#' @param FT2D a `list` from `fft2d()`
#' @param xdecades `numeric`, how decades should be plotted in the x-direction
#' @param ydecades `numeric`, how decades should be plotted in the y-direction
#' @return a `ggplot` object
#' @importFrom rlang .data
#' @export
#' @keywords fft2d_viz
spectrum_plot <- function(binned_power_spectrum, FT2D, xdecades = 3, ydecades = 3){
		.x <- NULL
		df_bin <- data.frame(frequency = 10^binned_power_spectrum[, 1], normalized_power = 10^binned_power_spectrum[, 2])
		df_complete <- data.frame(frequency = FT2D$radial_frequency_vector, normalized_power = FT2D$spectral_power_vector)
		p1 <- ggplot2::ggplot() +
			ggplot2::geom_point(data = df_complete, ggplot2::aes(x = .data$frequency , y = .data$normalized_power, alpha = 0.1)) +
			ggplot2::geom_point(data = df_bin, ggplot2::aes(x = .data$frequency , y = .data$normalized_power, color = "red")) +
			ggplot2::labs(title = "Topography power spectrum") +
			ggplot2::labs(y= bquote("DFT mean squared amplitude "~(m^2)), x = bquote("Wavenumber "~(m^{-1}))) +
			ggplot2::scale_x_log10(
				breaks = scales::trans_breaks(n = xdecades, 'log10', function(x) 10^x),
	            labels = scales::trans_format('log10', scales::math_format(10^.x)),
	            sec.axis = ggplot2::sec_axis(~1/., 
	            	breaks = scales::trans_breaks(n = xdecades, 'log10', function(x) 10^x), 
	            	labels = scales::trans_format('log10', scales::math_format(10^.x)),
	            	name = "Wavelength (m)")
	            	) +
			ggplot2::scale_y_log10(
				breaks = scales::trans_breaks(n = ydecades, 'log10', function(x) 10^x),
	            labels = scales::trans_format('log10', scales::math_format(10^.x))
	            ) + 
			ggpubr::theme_pubr() +
			ggplot2::guides(color = FALSE, alpha = FALSE)
	    return(p1)
}