在R中使用ggplot在对数-对数图中显示图例

Question

I have the following code which plots the data in log-log plot,

mp <- ggplot(cur_df,aes(x = Frequency, y = C_0V)) +
scale_x_log10(breaks = trans_breaks("log10", function(x) 10^x), labels = trans_format("log10", math_format(10^.x))) +
scale_y_log10(breaks = trans_breaks("log10", function(x) 10^x), labels = trans_format("log10", math_format(10^.x))) +
labs(x="t", y=expression ( bold(paste("J (A/", cm^2, ")", sep = "")) ) ) +
theme_bw() +
theme(axis.text=element_text(size=24)) +
theme(axis.title=element_text(size=20,face="bold"))+
annotation_logticks(sides = "trbl") +
theme(panel.grid.minor = element_blank()) +
geom_point() +
geom_point(data = cur_df, aes(y = C_ngv1V), colour = ' firebrick1', size = 1.5)

Mydata is the following,

t   C_0V    C_ngv1V
10  3.72E-09    -4.88E-09
12.58925    3.63E-09    -2.16E-09
15.84893    3.71E-09    -1.35E-09
19.95262    3.47E-09    -1.43E-09
25.11887    3.33E-09    1.76E-09
31.62278    3.41E-09    1.54E-09
39.81072    3.44E-09    2.68E-09
50.11873    3.62E-09    2.18E-09
63.09575    3.32E-09    3.00E-09
79.43285    3.33E-09    3.30E-09
100 3.33E-09    3.32E-09
125.8926    3.30E-09    3.62E-09
158.4894    3.36E-09    3.72E-09
199.5263    3.33E-09    3.93E-09
251.1887    3.25E-09    3.96E-09
316.2279    3.22E-09    4.08E-09
398.1073    3.20E-09    4.10E-09
501.1874    3.23E-09    4.14E-09
630.9576    3.21E-09    4.09E-09
794.3286    3.16E-09    4.12E-09
1000    3.11E-09    4.05E-09
1258.926    3.03E-09    4.00E-09
1584.894    2.97E-09    3.90E-09
1995.263    2.89E-09    3.82E-09
2511.888    2.79E-09    3.71E-09
3162.28 2.69E-09    3.56E-09
3981.074    2.59E-09    3.41E-09
5011.875    2.50E-09    3.25E-09
6309.578    2.41E-09    3.10E-09
7943.288    2.32E-09    2.93E-09
10000.01    2.23E-09    2.76E-09
12589.26    2.15E-09    2.59E-09
15848.94    2.06E-09    2.43E-09
19952.64    1.97E-09    2.29E-09
25118.88    1.87E-09    2.16E-09
31622.8 1.77E-09    2.04E-09
39810.75    1.67E-09    1.93E-09
50118.77    1.56E-09    1.83E-09
63095.79    1.45E-09    1.72E-09
79432.89    1.35E-09    1.61E-09
100000.1    1.25E-09    1.48E-09
125892.6    1.16E-09    1.36E-09
158489.5    1.07E-09    1.22E-09
199526.4    9.66E-10    1.08E-09
251188.9    8.94E-10    9.53E-10
316228.1    8.24E-10    8.29E-10
398107.6    7.52E-10    7.12E-10
501187.8    6.74E-10    6.02E-10
630958  1.38E-10    4.89E-10
794329.1    7.42E-11    3.59E-10
1.00E+06    5.64E-11    1.92E-10

Now to display the legend, I use the following code but for some reason the legend is not displayed in the plot.

mp + theme(legend.position = 'right')

Could someone point out what should be corrected here to display the legend in the right side of the plot.

When I plot mp it looks like this without any legend,

Answer 1

我认为颜色和尺寸应该在Aes内

     geom_point(data = cur_df, aes(y = C_ngv1V, colour = ' firebrick1', size = 1.5))