如何在r中平滑ecdf图

时间:2018-01-04 17:23:22

标签: r ggplot2 cdf ecdf

我有 // https://github.com/pubkey/rxdb/blob/master/src/rx-schema.js export function getIndexes(jsonID, prePath = '') { let indexes = []; Object.entries(jsonID).forEach(entry => { const key = entry[0]; const obj = entry[1]; const path = key === 'properties' ? prePath : util.trimDots(prePath + '.' + key); if (obj.index) indexes.push([path]); if (typeof obj === 'object' && !Array.isArray(obj)) { const add = getIndexes(obj, path); indexes = indexes.concat(add); } }); if (prePath === '') { const addCompound = jsonID.compoundIndexes || []; indexes = indexes.concat(addCompound); } indexes = indexes .filter((elem, pos, arr) => arr.indexOf(elem) === pos); // unique; return indexes; } df个变量,

头(DF,15)

5

使用 junc N1.ir N2.ir W1.ir W2.ir W3.ir 1 pos$chr1:3197398 0.000000 0.000000 0.000000 0.000000 0.000000 2 pos$chr1:3207049 0.000000 0.000000 0.000000 0.000000 0.000000 3 pos$chr1:3411982 0.000000 0.000000 0.000000 0.000000 0.000000 4 pos$chr1:4342162 0.000000 0.000000 0.000000 0.000000 0.000000 5 pos$chr1:4342918 0.000000 0.000000 0.000000 0.000000 0.000000 6 pos$chr1:4767729 -4.369234 -5.123382 -4.738768 -4.643856 -5.034646 7 pos$chr1:4772814 -3.841302 -3.891419 -4.025029 -3.643856 -3.184425 8 pos$chr1:4798063 -5.038919 -4.847997 -5.497187 -4.035624 -7.543032 9 pos$chr1:4798567 -4.735325 -5.096862 -3.882643 -3.227069 -4.983808 10 pos$chr1:4818730 -8.366322 -7.118941 -8.280771 -6.629357 -6.876517 11 pos$chr1:4820396 -5.514573 -6.330917 -5.898853 -4.700440 -5.830075 12 pos$chr1:4822462 -5.580662 -6.914883 -5.562242 -5.380822 -5.703211 13 pos$chr1:4827155 -4.333273 -4.600904 -4.133399 -4.012824 -3.708345 14 pos$chr1:4829569 -4.287866 -3.874469 -3.977280 -4.209453 -4.490326 15 pos$chr1:4857613 -6.902074 -6.074141 -6.116864 -3.989946 -6.474259

后几行
melt

总结

> head(ir.m)
              junc variable     value
1 pos$chr1:3197398 N1.ir  0.000000
2 pos$chr1:3207049 N1.ir  0.000000
3 pos$chr1:3411982 N1.ir  0.000000
4 pos$chr1:4342162 N1.ir  0.000000
5 pos$chr1:4342918 N1.ir  0.000000
6 pos$chr1:4767729 N1.ir -4.369234

我试图使用> summary(ir) junc N1.ir N2.ir W1.ir neg$chr1:100030088: 1 Min. :-11.962 Min. :-12.141 Min. :-11.817 neg$chr1:100039873: 1 1st Qu.: -4.379 1st Qu.: -4.217 1st Qu.: -4.158 neg$chr1:10023338 : 1 Median : -2.807 Median : -2.663 Median : -2.585 neg$chr1:10024088 : 1 Mean : -2.556 Mean : -2.434 Mean : -2.362 neg$chr1:10025009 : 1 3rd Qu.: 0.000 3rd Qu.: 0.000 3rd Qu.: 0.000 neg$chr1:10027750 : 1 Max. : 17.708 Max. : 16.162 Max. : 16.210 (Other) :113310 W2.ir W3.ir Min. :-12.194 Min. :-11.880 1st Qu.: -3.078 1st Qu.: -4.087 Median : -1.000 Median : -2.711 Mean : -1.577 Mean : -2.370 3rd Qu.: 0.000 3rd Qu.: 0.000 Max. : 17.562 Max. : 16.711 ggplot

绘制累积概率

使用此代码

stat_ecdf

Plot看起来像这样,

enter image description here

如何获得平滑的曲线?我是否需要执行更多统计操作才能获得该操作?

更新了代码

ggplot(ir.m, aes(x=value)) + stat_ecdf(aes(group=variable,colour = variable))

ir.d = as.data.frame(ir.m)
denss = split(ir.d, ir.d$variable) %>%
  map_df(function(dw) {
    denss = density(dw$value, from=min(ir.d$value) - 0.05*diff(range(ir.d$value)), 
                   to=max(ir.d$value) + 0.05*diff(range(ir.d$value)))
    data.frame(x=denss$x, y=denss$y, cd=cumsum(denss$y)/sum(denss$y), group=dw$variable[1])
    head(denss)
  })
summary(denss)
> summary(denss)
       x                 y                   cd               group    
 Min.   :-13.689   Min.   :0.0000000   Min.   :0.00000   N1.ir:512  
 1st Qu.: -5.466   1st Qu.:0.0000046   1st Qu.:0.07061   N2.ir:512  
 Median :  2.757   Median :0.0002487   Median :0.99552   W1.ir  :512  
 Mean   :  2.757   Mean   :0.0303942   Mean   :0.65315   W2.ir  :512  
 3rd Qu.: 10.980   3rd Qu.:0.0148074   3rd Qu.:0.99997   W3.ir  :512  
 Max.   : 19.203   Max.   :0.9440592   Max.   :1.00000

enter image description here

2 个答案:

答案 0 :(得分:7)

ecdf完全遵循数据,没有任何平滑。但是,您可以通过从数据生成核密度估计(基本上是平滑的直方图)并从中创建“ecdf”来创建平滑的累积密度。这是假数据的一个例子:

首先,我们使用density函数生成核密度估计。默认情况下,这给出了512 x值网格上的密度估计值。然后我们使用它作为计算ecdf的“数据”,这只是密度的累积和(或者,对于任何给定点 a 沿x轴,ecdf的值< em> a 是核密度曲线下的区域(即从 -Inf a 的积分)。

我已将代码保密到下面的函数中,以便您可以看到更改密度函数的adjust参数如何更改平滑的ecdf。较小的adjust值会减少平滑量,从而产生更接近数据的密度估计值。您可以在下面的图中看到,设置adj=0.1会使平滑的ecdf平滑得更少,以便更接近原始ecdf中的步骤。

library(ggplot2)

smooth_ecd = function(adj = 1) {

  # Fake data
  set.seed(2)       
  dat = data.frame(x=rnorm(15))

  # Extend range of density estimate beyond data
  e = 0.3 * diff(range(dat$x))

  # Kernel density estimate of fake data
  dens = density(dat$x, adjust=adj, from=min(dat$x)-e, to=max(dat$x) +e)
  dens = data.frame(x=dens$x, y=dens$y)

  # Plot kernel density (blue), ecdf (red) and smoothed ecdf (black)
  ggplot(dat, aes(x)) + 
    geom_density(adjust=adj, colour="blue", alpha=0.7) +
    geom_line(data=dens, aes(x=x, y=cumsum(y)/sum(y)), size=0.7, colour='grey30') +
    stat_ecdf(colour="red", size=0.6, alpha=0.6) +
    theme_classic() +
    labs(title=paste0("adj=",adj))
}

smooth_ecd(adj=1)
smooth_ecd(adj=0.3)
smooth_ecd(adj=0.1)

enter image description here

以下是按组执行此操作的一些代码:

library(tidyverse)

# Fake data with two groups
set.seed(2)
dat = data.frame(x=c(rnorm(15, 0, 1), rnorm(20, 0.2, 0.8)), 
                 group=rep(LETTERS[1:2], c(15,20)))

# Split the data by group and calculate the smoothed cumulative density for each group
dens = split(dat, dat$group) %>% 
  map_df(function(d) {
    dens = density(d$x, adjust=0.1, from=min(dat$x) - 0.05*diff(range(dat$x)), 
                   to=max(dat$x) + 0.05*diff(range(dat$x)))
    data.frame(x=dens$x, y=dens$y, cd=cumsum(dens$y)/sum(dens$y), group=d$group[1])
  })

现在我们可以绘制每个平滑的累积密度。在下面的图中,我已经包含了对stat_ecdf的调用以及原始数据的比较。

ggplot() +
  stat_ecdf(data=dat, aes(x, colour=group), alpha=0.8, lty="11") +
  geom_line(data=dens, aes(x, cd, colour=group)) +
  theme_classic()

enter image description here

更新:使用您的数据示例,这是我得到的。我不知道你是如何将那个长核苷酸串作为你的图中的x值,因为这样的变量不会出现在你发布的数据中的任何地方。

# Melt data
dat = gather(df, variable, value, -junc)

# Split the data by group and calculate the smoothed cumulative density for each group
dens = split(dat, dat$variable) %>% 
  map_df(function(d) {
    dens = density(d$value, adjust=0.1, from=min(dat$value) - 0.05*diff(range(dat$value)), 
                   to=max(dat$value) + 0.05*diff(range(dat$value)))
    data.frame(x=dens$x, y=dens$y, cd=cumsum(dens$y)/sum(dens$y), group=d$variable[1])
  })

ggplot() +
  stat_ecdf(data=dat, aes(value, colour=variable), alpha=0.8, lty="11") +
  geom_line(data=dens, aes(x, cd, colour=group)) +
  theme_classic()

enter image description here

答案 1 :(得分:0)

这是一个较旧的线程,但是,我只想提到stat_ecdf(..., geom = "line")对于某些人来说可以避免ecdf曲线中geom_step的步伐。 -迈克尔

enter image description here