圖例中GGPLOT2

Question

我有一個數據幀df：

structure(list(y = c(2268.14043972082, 2147.62290922552, 2269.1387550775, 
2247.31983098201, 1903.39138268307, 2174.78291538358, 2359.51909126411, 
2488.39004804939, 212.851575751527, 461.398994384333, 567.150629704352, 
781.775113821961, 918.303706148872, 1107.37695799186, 1160.80594193377, 
1412.61328924168, 1689.48879626486, 260.737164468854, 306.72700499362, 
283.410379620422, 366.813913489692, 387.570173754128, 388.602676983443, 
477.858510450125, 128.198042456082, 535.519377609133, 1028.8780498564, 
1098.54431357711, 1265.26965941035, 1129.58344809909, 820.922447928053, 
749.343583476846, 779.678206156474, 646.575242339517, 733.953282899613, 
461.156280127354, 906.813018662913, 798.186995701282, 831.365377249207, 
764.519073183124, 672.076289062505, 669.879217186302, 1341.47673353751, 
1401.44881976186, 1640.27575962036), P = c(1750.51986303926, 
1614.11541634798, 951.847023338079, 1119.3682884872, 1112.38984390156, 
1270.65773075982, 1234.72262170166, 1338.46096616983, 1198.95775346458, 
1136.69287367165, 1265.46480803983, 1364.70149818063, 1112.37006707489, 
1346.49240261316, 1740.56677791104, 1410.99217295647, 1693.18871380948, 
901.760176040232, 763.971046562772, 994.8699095021, 972.755147593882, 
1011.41669411398, 643.705302958842, 537.54384616157, 591.212003320456, 
464.405641604215, 0, 0, 0, 0, 0, 246.197052353527, 265.237238116562, 
1260.68540103734, 398.080919081345, 0, 374.611004248261, 527.686996757984, 
765.678002953529, 661.830007851124, 484.864011824131, 612.936006393284, 
672.088483441621, 625.397994920611, 785.390003710985), x = c(49, 
50, 51, 52, 53, 54, 55, 56, 1, 2, 3, 4, 5, 14, 15, 16, 17, 2, 
3, 4, 5, 6, 10, 11, 3, 30, 64, 66, 67, 68, 69, 34, 35, 37, 39, 
2, 17, 18, 99, 100, 102, 103, 67, 70, 72), Te = c(9.10006221322572, 
7.65505467142961, 8.21480062559674, 8.09251754304318, 8.466220758789, 
8.48094407814006, 8.77304120569444, 8.31727518543397, 8.14410265791868, 
8.80921738865237, 9.04091478341757, 9.66233618146246, 8.77015716015164, 
9.46037931956657, 9.59702379240667, 10.1739258740118, 9.39524442215692, 
0.616491147620629, 0.631476354027448, 0.129135682201776, 1.87297579763483, 
2.53941370394744, -0.518422834982312, 1.34466852591922, 1.05118063842584, 
1.79515935418336, 6.65555189859301, 6.38647333946436, 6.48427760143803, 
6.33587322941382, 7.3501870975794, 3.04366850755114, 1.94656549866681, 
3.61970174782833, 4.41939287295897, 9.47923019665153, 8.87480698915229, 
8.06993784515111, 2.31976094801132, 2.65270969716837, 2.21586561444892, 
2.66012522311856, 5.72634186318572, 4.63445162539409, 6.18505171198551 
)), .Names = c("y", "P", "x", "Te"), row.names = c(NA, -45L), class = "data.frame") 

我想繪製這個數據就像我ggplot做：

library(ggplot2) 
gg3 <- ggplot(df) + 
     geom_point(aes(x = x, y = y, size=P, colour=Te), alpha=0.7, inherit.aes = FALSE)+ 
     scale_colour_gradient(low="#00FF33", high ="#FF0000")+ 
     labs(colour="T", size="P")+ 
     xlab("x") + ylab("y")+ 
     # ylim(0,3000)+ 
     scale_size(range = c(3, 8)) + 
     theme_bw(base_size = 12, base_family = "Helvetica") + 
     theme(panel.grid.minor = element_line(colour="grey", size=0.5)) + 
     theme(axis.text.x = element_text(angle = 45, hjust = 1)) 
    print(gg3) 

這是完全是我想要的，但我希望在圖例下面有一個水平方向的圖例和圖例頂部的圖例標題。我通過添加此命令行theme(legend.position="bottom", legend.direction="horizontal")設法將圖例置於圖下方。但是，我無法真正設法將傳奇頭銜放在傳奇之上。有誰知道我該怎麼做？

Answer 1

爲了實現這個目標，您必須同時使用theme(legend.position="bottom")以及guide_legend。使用後者，您可以更改圖例標題的位置。

有了：

ggplot(df) + 
    geom_point(aes(x = x, y = y, size=P, colour=Te), alpha=0.7) + 
    scale_colour_gradient(low="#00FF33", high ="#FF0000", guide = "colourbar")+ 
    labs(colour="T", size="P")+ 
    xlab("x") + ylab("y")+ 
    scale_size(range = c(3, 8)) + 
    theme_bw(base_size = 12, base_family = "Helvetica") + 
    theme(panel.grid.minor = element_line(colour="grey", size=0.5), 
     axis.text.x = element_text(angle = 45, hjust = 1), 
     legend.position="bottom", 
     legend.box="horizontal") + 
    guides(colour = guide_colourbar(title.position="top", title.hjust = 0.5), 
     size = guide_legend(title.position="top", title.hjust = 0.5)) 

你：