R/plot_differentialTest.R

In corncob: Count Regression for Correlated Observations with the Beta-Binomial

#' differentialTest plot function
#'
#' @param x Object of class \code{differentialTest}
#' @param level (Optional). Character vector. Desired taxonomic levels for taxa labels.
#' @param data_only (Optional). Default \code{FALSE}. Boolean. If \code{TRUE}, only returns data frame.
#' @param ... No optional arguments are accepted at this time.
#'
#'
#' @return Object of class \code{ggplot}. Plot of coefficients from models for significant taxa from \code{differentialTest}
#'
#' @examples
#' # phyloseq example
#' data(soil_phylum_small_sample)
#' data(soil_phylum_small_otu)
#' da_analysis <- differentialTest(formula = ~ DayAmdmt,
#'                                 phi.formula = ~ DayAmdmt,
#'                                 formula_null = ~ 1,
#'                                 phi.formula_null = ~ DayAmdmt,
#'                                 test = "Wald", boot = FALSE,
#'                                 data = soil_phylum_small_otu,
#'                                 sample_data = soil_phylum_small_sample,
#'                                 fdr_cutoff = 0.05,
#'                                 try_only = 1:5)
#' plot(da_analysis, level = "Phylum")
#'
#' @export
plot.differentialTest <- function(x, level = NULL, data_only = FALSE, ...) {
  signif_taxa <- x$significant_taxa
  if ("phyloseq" %in% class(x$data)) {
    if (!is.null(x$data@tax_table)) {
      signif_taxa <- otu_to_taxonomy(signif_taxa, x$data, level = level)
      if (length(unique(signif_taxa)) != length(unique(x$significant_taxa))) {
        # Make sure if repeated taxa add unique otu identifiers
        signif_taxa <- paste0(signif_taxa, " (", x$significant_taxa, ")")
      }
    }
  }
  if (length(x$significant_models) != 0) {
    var_per_mod <- length(x$restrictions_DA) + length(x$restrictions_DV)
    total_var_count <- length(signif_taxa) * var_per_mod
    df <- as.data.frame(matrix(NA, nrow = total_var_count, ncol = 5))
    colnames(df) <- c("x", "xmin", "xmax", "taxa", "variable")
    qval <- stats::qnorm(.975)
    restricts_mu <- attr(x$restrictions_DA, "index")
    restricts_phi <- attr(x$restrictions_DV, "index")

    count <- 1
    for (i in 1:length(x$significant_models)) {

      # Below from print_summary_bbdml, just to get coefficient names
      tmp <- x$significant_models[[i]]
      coefs.mu <- tmp$coefficients[1:tmp$np.mu,, drop = FALSE]
      rownames(coefs.mu) <- paste0(substring(rownames(coefs.mu), 4), "\nDifferential Abundance")
      coefs.mu <- coefs.mu[restricts_mu,, drop = FALSE]

      coefs.phi <- tmp$coefficients[(tmp$np.mu + 1):nrow(tmp$coefficients),, drop = FALSE]
      rownames(coefs.phi) <- paste0(substring(rownames(coefs.phi), 5), "\nDifferential Variability")
      coefs.phi <- coefs.phi[restricts_phi - tmp$np.mu,, drop = FALSE]

      coefs <- rbind(coefs.mu, coefs.phi)
      for (j in 1:var_per_mod) {
        df[count, 1:3] <- c(coefs[j, 1], coefs[j, 1] - qval * coefs[j, 2],
                        coefs[j, 1] + qval * coefs[j, 2])
        df[count, 4:5] <- c(signif_taxa[i], rownames(coefs)[j])
        count <- count + 1
      }
    }
    if (!(data_only)) {
    # global variables warning suppression
    taxa <- xmin <- xmax <- NULL

    ggplot2::ggplot(df, ggplot2::aes(x = x, y = taxa)) +
      ggplot2::geom_vline(xintercept = 0, color = "gray50", lty = "dashed",
                          alpha = 0.75, lwd = 1) +
      ggplot2::geom_point() +
      ggplot2::geom_errorbarh(ggplot2::aes(xmin = xmin, xmax = xmax, colour = xmin<=0 & xmax <= 0| xmin>=0 & xmax >= 0), height = .3) +
      ggplot2::theme_bw() +
      ggplot2::facet_wrap(~variable, scales = "free_x", nrow = 1) +
      ggplot2::labs(title = "", x = "", y = "Taxa") +
      ggplot2::scale_y_discrete(limits = rev(df$taxa)) +
      ggplot2::scale_x_continuous(breaks = scales::pretty_breaks(n = 5)) +
      ggplot2::theme(axis.text.x = ggplot2::element_text(angle = 45, hjust = 1))
    } else {
    return(df)
  }
  } else {
    message("No taxa were found to be significantly different using your model specification. \nPlease verify that your formulas are correctly specified.")
  }
}