在格子圖中使用圖案添加/替代背景顏色

Question

我使用R格子包中的等級圖。我的結果如下圖所示。

我現在的問題是，我需要生成一個黑白版本的打印。

有沒有辦法將顏色更改爲灰度，並給矩形一個背景圖案，以便紅色與藍色區別一次？例如，想到點或斜線。

謝謝！

Answer 1

我找到了一種方法手動繪製成levelplot面板，並提請在全部小區的對角線填充圖案值大於0.5

然而更大的，我不能設法在顏色關鍵圖例中繪製相同的圖案。經過幾個小時的閱讀論壇，並試圖瞭解格子源代碼，我無法得知線索。也許別人可以解決這個問題。以下是我的了：

library(lattice) 
library(RColorBrewer) 
cols <- colorRampPalette(brewer.pal(8, "RdBu")) 

data <- Harman23.cor$cov  

fx <- fy <- c() 
for (r in seq(nrow(data))) 
    for (c in seq(ncol(data))) 
    { 
    if (data[r, c] > 0.5) 
    { 
     fx <- c(fx, r); 
     fy <- c(fy, c); 
    } 
    } 

diag_pattern <- function(...) 
{ 
    panel.levelplot(...) 
    for (i in seq(length(fx))) 
    { 
    panel.linejoin(x = c(fx[i],fx[i]+.5), y= c(fy[i]+.5,fy[i]), col="black") 
    panel.linejoin(x = c(fx[i]-.5,fx[i]+.5), y= c(fy[i]+.5,fy[i]-.5), col="black") 
    panel.linejoin(x = c(fx[i]-.5,fx[i]), y= c(fy[i],fy[i]-.5), col="black") 
    } 
}  

p <- levelplot(data, scales=list(x=list(rot=45)), 
       xlab="", ylab="", col.regions=cols, panel=diag_pattern) 
print(p) 

Answer 2

使用兩個以上的模式（例如45°和135°定向的線具有不同密度的）將是混亂的，IMO。 （儘管事實上我不知道如何使用點陣來實現這一點）。通過使用灰度可以實現可讀模式，請參閱levelplot()中的col.regions參數。

library(RColorBrewer) 
cols <- colorRampPalette(brewer.pal(8, "RdBu")) 
p <- levelplot(Harman23.cor$cov, scales=list(x=list(rot=45)), 
       xlab="", ylab="", col.regions=cols) 
# versus all greys 
p <- levelplot(Harman23.cor$cov, scales=list(x=list(rot=45)), 
       xlab="", ylab="", col.regions=gray.colors) 
p <- levelplot(Harman23.cor$cov, scales=list(x=list(rot=45)), 
       xlab="", ylab="", col.regions=gray.colors(6), cuts=6) 

Answer 3

點會更容易增加，簡單地增加在上面panel.points。給傳說添加點可能有點困難。以下函數在網格圖形中執行。

grid.colorbar(runif(10, -2, 5)) 

require(RColorBrewer) 
require(scales) 

diverging_palette <- function(d = NULL, centered = FALSE, midpoint = 0, 
           colors = RColorBrewer::brewer.pal(7,"PRGn")){ 

    half <- length(colors)/2 

    if(!length(colors)%%2) 
    stop("requires odd number of colors") 
    if(!centered && !(midpoint <= max(d) && midpoint >= min(d))) 
    warning("Midpoint is outside the data range!") 

    values <- if(!centered) { 
    low <- seq(min(d), midpoint, length=half) 
    high <- seq(midpoint, max(d), length=half) 
    c(low[-length(low)], midpoint, high[-1]) 
    } else { 
    mabs <- max(abs(d - midpoint)) 
    seq(midpoint-mabs, midpoint + mabs, length=length(colors)) 
    } 

    scales::gradient_n_pal(colors, values = values) 

} 

colorbarGrob <- function(d, x = unit(0.5, "npc"), 
         y = unit(0.1,"npc"), 
         height=unit(0.8,"npc"), 
         width=unit(0.5, "cm"), size=0.7, 
         margin=unit(1,"mm"), tick.length=0.2*width, 
         pretty.breaks = grid.pretty(range(d)), 
         digits = 2, show.extrema=TRUE, 
         palette = diverging_palette(d), n = 1e2, 
         point.negative=TRUE, gap =5, 
         interpolate=TRUE, 
         ...){ 

    ## includes extreme limits of the data 
    legend.vals <- unique(round(sort(c(pretty.breaks, min(d), max(d))), digits)) 

    legend.labs <- if(show.extrema) 
    legend.vals else unique(round(sort(pretty.breaks), digits)) 

    ## interpolate the colors 
    colors <- palette(seq(min(d), max(d), length=n)) 
    ## 1D strip of colors, from bottom <-> min(d) to top <-> max(d) 
    lg <- rasterGrob(rev(colors), # rasterGrob draws from top to bottom 
        y=y, interpolate=interpolate, 
        x=x, just=c("left", "bottom"), 
        width=width, height=height) 


    ## box around color strip 
    bg <- rectGrob(x=x, y=y, just=c("left", "bottom"), 
       width=width, height=height, gp=gpar(fill="transparent")) 

    ## positions of the tick marks 
    pos.y <- y + height * rescale(legend.vals) 
    if(!show.extrema) pos.y <- pos.y[-c(1, length(pos.y))] 

    ## tick labels 
    ltg <- textGrob(legend.labs, x = x + width + margin, y=pos.y, 
          just=c("left", "center")) 
    ## right tick marks 
    rticks <- segmentsGrob(y0=pos.y, y1=pos.y, 
         x0 = x + width, 
         x1 = x + width - tick.length, 
         gp=gpar()) 
    ## left tick marks 
lticks <- segmentsGrob(y0=pos.y, y1=pos.y, 
         x0 = x , 
         x1 = x + tick.length, 
         gp=gpar()) 

    ## position of the dots 
    if(any(d < 0)){ 
    yneg <- diff(range(c(0, d[d<0])))/diff(range(d)) * height 
    clipvp <- viewport(clip=TRUE, x=x, y=y, width=width, height=yneg, 
        just=c("left", "bottom")) 
    h <- convertUnit(yneg, "mm", "y", valueOnly=TRUE) 

    pos <- seq(0, to=h, by=gap) 
    } 
    ## coloured dots 
    cg <- if(!point.negative || !any(d < 0)) nullGrob() else 
    pointsGrob(x=unit(rep(0.5, length(pos)), "npc"), y = y + unit(pos, "mm") , 
      pch=21, gp=gpar(col="white", fill="black"),size=unit(size*gap, "mm"), vp=clipvp) 
    ## for more general pattern use the following 
    ## gridExtra::patternGrob(x=unit(0.5, "npc"), y = unit(0.5, "npc") , height=unit(h,"mm"), 
    ## pattern=1,granularity=unit(2,"mm"), gp=gpar(col="black"), vp=clipvp) 

    gTree(children=gList(lg, lticks, rticks, ltg, bg, cg), 
     width = width + margin + max(stringWidth(legend.vals)), ... , cl="colorbar") 
} 

grid.colorbar <- function(...){ 
    g <- colorbarGrob(...) 
    grid.draw(g) 
    invisible(g) 
} 

widthDetails.colorbar <- function(x){ 
x$width 
} 

編輯：爲圖案填充，可以取代pointsGrob與gridExtra::patternGrob（你也可以爲基體的瓷磚做）。