R: 公式成曲线

1 默认plot（来自参考）

创建函数

# Create own functions
my_fun1 <- function(x) { x^3 - x * 300 }           
my_fun2 <- function(x) { x^3 * 2 + x^2 + x * 10 + 5 * 10^10 }
my_fun3 <- function(x) { - x^3 + x^2 - 2 * 10^10 }

plot 保存

pdf("test_plot.pdf")
curve(my_fun1, from = -5000, to = 5000, col = 2)  # Draw Base R plot
curve(my_fun2, from = -5000, to = 5000, col = 3, add = TRUE)
curve(my_fun3, from = -5000, to = 5000, col = 4, add = TRUE)
dev.off()

2 ggplot（来自参考）

统合公式，ggplot准备

library("ggplot2") 
# Create data for ggplot2
data_fun <- data.frame(x = -5000:5000,            
                       values = c(my_fun1(-5000:5000),
                                  my_fun2(-5000:5000),
                                  my_fun3(-5000:5000)),
                       fun = rep(c("fun1", "fun2", "fun3"), 
                       each = 10001))
head(data_fun)

ggplot

# Draw ggplot2 plot
ggplot(data_fun, aes(x, values, col = fun)) +
  geom_line()

3 一个ggplot绘制公式曲线案例

函数参数

a1 = 4319.64; b1 = 0.229837
a2 = 2486.19; b2 = 0.157168
a3 = 2015.95; b3 = 0.185205

写好函数

my_fun1 <- function(x) {a1 * x^b1}
my_fun2 <- function(x) {a2 * x^b2}
my_fun3 <- function(x) {a3 * x^b3}

普通曲线

curve(my_fun1, from = 0, to = 16, col = 2)
curve(my_fun2, from = 0, to = 22, col = 3, add = TRUE)
curve(my_fun3, from = 0, to = 16, col = 4, add = TRUE)

准备ggplot数据框

准备x，用函数计算y，ggplot line即可出结果

library("ggplot2") 
data <- data.frame(x = c(1:16,
                         1:22,
                         1:16),            
                       values = c(my_fun1(1:16),
                                  my_fun2(1:22),
                                  my_fun3(1:16)),
                       fun = c(rep("Escherichia flexneri", 16),
                               rep("Enterococcus faecalis", 22),
                               rep("Lactobacillus amylovorus", 16)))

准备标签和颜色

genomes = c("Escherichia flexneri",
"Limosilactobacillus reuteri",
"Enterococcus faecalis")
genomes = factor(genomes, levels = genomes)

col_list = read.table("C:/Users/hutongyuan/Desktop/group_color.list",sep="\t", check.names=F, na.string="", stringsAsFactors=F, quote="", comment.char="")
colors = col_list$V1[1:3]
names(colors) <- genomes

ggplot
技巧
1 scale_x_continous 设置x轴标签
2 scale_color_manual 使用配置颜色
3 theme(legend.posiotn = c()) 任意设置legend位置

pic = 
ggplot(data, aes(x, values, col = fun)) +
  geom_line(size = 1) +
  theme_classic() +
  labs(x = "Number of Genomes", 
       y = "Number of Pangenome Families", 
       color = "") +
  theme(legend.text = element_text(size=15),
        legend.title = element_text(face='bold', size=20),
        legend.position = c(0.75, 0.7),
        legend.background = element_rect(color = "black",
                                         linetype = "solid", 
                                         size = 1)) +
  theme(axis.text.x = element_text(size = 15),
        axis.text.y = element_text(size = 18),
        axis.title = element_text(size = 22),
        axis.line = element_line(size = 1),
        axis.ticks = element_line(size = 1)) +
  scale_color_manual(values = colors) +
  scale_x_continuous(limits = c(1, 50),
                     breaks = c(1, 10, 20, 30, 40, 50))

ggsave(pic, filename = "all_pan_curve_test.pdf", width = 8)

参考：
Draw Multiple Function Curves to Same Plot in R (2 Examples)
R语言作图：数学公式 【公式书写】