如何从数据帧的折线图中 plot 误差条

Question

I have two dataframes, df_avg and df_sem, which contain mean values and standard errors of the means, respectively. For example:

        KPCmb1      KPCmb1IA    KPCmb2      KPCmb3      KPCmb4      KPCmb5      KPCmb6
temp                            
19.99   15.185905   24.954296   22.610052   29.249107   26.151815   34.374257   36.589218
20.08   15.198452   24.998227   22.615342   29.229325   26.187794   34.343738   36.596730
20.23   15.208917   25.055061   22.647499   29.234424   26.193382   34.363549   36.580033
20.47   15.244485   25.092773   22.691421   29.206816   26.202425   34.337385   36.640839
20.62   15.270921   25.145798   22.720752   29.217821   26.235101   34.364162   36.600030

and

        KPCmb1      KPCmb1IA    KPCmb2      KPCmb3      KPCmb4      KPCmb5      KPCmb6
temp                            
19.99   0.342735    0.983424    0.131502    0.893494    1.223318    0.536450    0.988185
20.08   0.347366    0.983732    0.136239    0.898661    1.230763    0.534779    0.993970
20.23   0.348641    0.981614    0.134729    0.898790    1.227567    0.529240    1.005609
20.47   0.350937    0.993973    0.138411    0.881142    1.237749    0.526841    0.991591
20.62   0.345863    0.983064    0.132934    0.883863    1.234746    0.533048    0.987520

I want to plot a line chart using temp as the x-axis and the dataframe columns as the y-axes. I also want to use the df_sem dataframe to provide error bars for each line (note the column names are the same between the two dataframes).

I can achieve this with the following code: df_avg.plot(yerr=df_sem) , but this does not allow me to change many aspects of the plot, like DPI, labels, and things like that.

So I've tried to make the plot using the following code as an alternative:

plt.figure()
x = df_avg.index
y = df_avg
plt.errorbar(x,y,yerr=df_sem)
plt.show()

But this gives me the error: ValueError: shape mismatch: objects cannot be broadcast to a single shape

How do I go about making the same chart that I am able to using pandas plotting with matplotlib plotting?

Thanks!

Answer 1

You can do just a simple for loop:

for col in df_avg.columns:
    plt.errorbar(df_avg.index, df_avg[col], yerr=df_sem[col], label=col)

plt.legend()

Output: