29 lines
1.0 KiB
R
29 lines
1.0 KiB
R
#' Plots a matrix as an image
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#'
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#' @param A a matrix to be plotted
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#' @param main overall title for the plot
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#' @param sub sub-title of the plot
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#' @param interpolate a logical vector (or scalar) indicating whether to apply
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#' linear interpolation to the image when drawing.
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#' @param ... further arguments passed to \code{\link{rasterImage}}
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#'
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#' @export
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matrixImage <- function(A, main = NULL, sub = NULL, interpolate = FALSE, ...) {
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# Scale values of `A` to [0, 1] with min mapped to 1 and max to 0.
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A <- (max(A) - A) / diff(range(A))
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# plot raster image
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plot(c(0, ncol(A)), c(0, nrow(A)), type = "n", bty = "n", col = "red",
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xlab = "", ylab = "", xaxt = "n", yaxt = "n", main = main, sub = sub)
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# Add X-axis giving index
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ind <- seq(1, ncol(A), by = 1)
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axis(1, at = ind - 0.5, labels = ind, lwd = 0, lwd.ticks = 1)
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# Add Y-axis
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ind <- seq(1, nrow(A))
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axis(2, at = ind - 0.5, labels = rev(ind), lwd = 0, lwd.ticks = 1, las = 1)
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rasterImage(A, 0, 0, ncol(A), nrow(A), interpolate = interpolate, ...)
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}
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