rggplot2

ggplot: error bars


I want to plot error bars of the two different set of value of y1, y2 with respect to x. In other words, I have two data Y1,Y2 and they are correspond X value. I managed to plot them together after I reshaped the data frame. Now I want to graph the error bars on the same graph for each Y1, Y2 points. I understand geom_errorbar() is what I'm looking for. However, I'm following long way to do that and I'm sure there is a short way. What I'm doing I'm calculating "se" for each set and calculate aes(ymin=y1-se, ymax=y+se) and repeat the same for Y2. Because I want to apply this error bars to different plots . I 'd rather do it in a short way.

Here my data frame after reshape:

M     Req      Rec      load       Un      L1
1    30.11  9.000000   3.000000  30.02000  A
2    50.31  10.030000  6.045000  39.44000  A
3    60.01  11.290000  7.366667  54.93000  A
4    66.10  12.630000  8.827500  68.44500  A
5    80.18  13.106000  9.462000  71.07600  A
6    87.10  14.421667  15.961667 82.70500  A
7    90.08  15.880000  20.644286 94.20714  A
1    4.000  1.500000    1.000000  1        B
2    8.240  6.240000    4.760000  3.00000  B
3    10.28  12.230000  9.420000  4.05000   B
4    18.570 25.570000 17.930000  6.00000   B
5    22.250 35.250000 27.850000  7.00000   B
6    35.070 55.010000 36.810000  8.06000   B
7    48.480  0.420000 47.020000  9.06000   B

I have used the following command to graph it:

ggplot(df_reshaped,aes(x = M, y = Req, colour = L1, shape=L1)) +  
     geom_point(size = 5)+
     geom_line() +
     scale_x_discrete(name="M") +
     scale_y_continuous(name="Y1 Y2")+
     ggtitle("A vs B")

In this case I'm graphing Y1=Req1, Y2=Req2, with respect to x=M

Any short way or suggestion to calculate the error bars ?

Is there any quick way to calculate the "se" ?


Solution

  • In general there are two possibilities to prepare your data for ggplot:

    Obviously, you have chosen the first approach. So, you just need to calculate the standard errors for the points of both variables.