Question

我遇到的问题与this question的最高回复相似但未得到解决。但是，我通过rpy2包在python中使用ggplot2，这带来了额外的困难。

我有许多不同的时间序列（带有变量名称），我想在数据系列旁边绘制（这是常量）。我希望数据系列在所有图中都是相同的颜色，但不关心其他系列的颜色。但是，如果我允许ggplot2自动分配颜色，它会按字母顺序排列，颜色也是如此映射不稳定，具体取决于系列名称是按字母顺序排在“数据”之前还是之后。（见下面的代码）

请注意，系列名称（代码示例中的'a_model'，'e_model'）并不是事先都知道的，所以我不能简单地创建一个包含所有可能系列名称的手动色标。此外，图表可能包括数据系列和多个其他系列。我只对保持数据系列的颜色不变感兴趣。

from rpy2 import robjects
from rpy2.robjects.lib import grid
from rpy2.robjects.packages import importr
import rpy2.robjects.lib.ggplot2 as ggplot2
from rpy2.robjects import pandas2ri
import pandas as pd
pandas2ri.activate()             

###Input data###
plot_data={}  
plot_data.update({'a_model':[0.217,0.226,0.238,0.253,0.272,0.278,0.283,0.29,0.296,0.298]})
plot_data.update({'data':[0.255,0.226,0.241,0.19,0.264,0.302,0.291,0.26,0.218,0.221]})
plot_data.update({'mos_since_start':[1,2,3,4,5,6,7,8,9,10]})

###Plotting Function###
def plot(plot_data, filename):
    df=pd.DataFrame(in_dict)
    fig = pd.melt(df, id_vars=['mos_since_start'])
    pp = ggplot2.ggplot(fig) + \
         ggplot2.aes_string(x='mos_since_start', 
         y='value',group='variable',colour='variable', shape = 'variable', linetype = 'variable') +\
         ggplot2.geom_line() + ggplot2.geom_point() 
     robjects.r.ggsave(filename=filename, plot=pp, width =12, height = 8)

###Plots###
plot(plot_data,"./testplot.pdf")
plot_data.update({'e_model':plot_data.pop('a_model')})
plot(plot_data,"./testplot2.pdf")

Answer 1

这不是用python编写的，但是应该显示使数据系列成为图例中第一个值的选项，这些值应该是图中的一致颜色

library(ggplot2)
library(reshape2)

df1 <- data.frame(a_model = c(0.217,0.226,0.238,0.253,0.272,0.278,0.283,0.29,0.296,0.298),
                  e_model = c(0.217,0.226,0.238,0.253,0.272,0.278,0.283,0.29,0.296,0.298),
                  data = c(0.255,0.226,0.241,0.19,0.264,0.302,0.291,0.26,0.218,0.221),
                  b_model = c(0.217,0.226,0.238,0.253,0.272,0.278,0.283,0.29,0.296,0.298),
                  mos_since_start = c(1,2,3,4,5,6,7,8,9,10))
dfm <- melt(df1, id.vars = "mos_since_start")

ggplot(dfm,
       aes(x = mos_since_start,
           y = value,
           group = variable,
           colour = variable,
           shape = variable,
           linetype = variable)) +
         geom_line() +
         geom_point() +
  scale_shape_discrete(name = "legend",
                       breaks = union("data", dfm$variable)) +
  scale_colour_discrete(name = "legend",
                        breaks = union("data", dfm$variable)) +
  scale_linetype_discrete(name = "legend",
                          breaks = union("data", dfm$variable))

可能更简单的第二种方法是更改variable

的系数顺序

dfm$variable <- relevel(dfm$variable, "data")

ggplot(dfm,
       aes(x = mos_since_start,
           y = value,
           group = variable,
           colour = variable,
           shape = variable,
           linetype = variable)) +
  geom_line() +
  geom_point()

使用Python中的ggplot2（rpy2）对分类变量进行稳定的颜色映射

1 个答案: