How to adjust the legend of pie chart

The following is my code

figure
    %----------------------------------------------------------------------
    subplot(2,3,1)%Figure1
    pre_ton  = [ore_ton waste_ton];
    t_labels = {'ORE','WASTE'};
    pie(pre_ton)
    title('Percentage of tonnage')
    legend(t_labels,'Location','southoutside','Orientation','horizontal','FontSize',7)
    %----------------------------------------------------------------------
    subplot(2,3,2)%Figure2
    pre_energy = [drill_energy blast_energy load_energy haul_energy crush_energy grind_energy];
    Labels     = {'Drill','Blast','Load','Haul','Crush','Grind'};
    pie(pre_energy)
    title('Energy consumption(%) of each stage')
    legend(Labels,'Location','westoutside','Orientation','vertical','FontSize',7)
    %----------------------------------------------------------------------
    subplot(2,3,3)%Figure3
    pre_GWP  = [drill_gwp blast_gwp load_gwp haul_gwp crush_gwp grind_gwp];
    Labels   = {'Drill','Blast','Load','Haul','Crush','Grind'};
    pie(pre_GWP)
    title('GWP(%) of each stage')
    legend(Labels,'Location','westoutside','Orientation','vertical','FontSize',7)
    %----------------------------------------------------------------------
    subplot(2,3,4)%Figure4
    tonnage  = diag([ore_ton waste_ton total_ton]);
    TONNAGE  = bar(tonnage,'stacked');
    title('Tonnage of open pit mine')
    ylabel('tonnage')
    legend('ORE', 'WASTE', 'TOTAL')
    %----------------------------------------------------------------------
    subplot(2,3,5)%Figure5
    energy  = diag([ore_energy waste_energy total_energy]);
    ENERGY  = bar(energy,'stacked');
    title('Energy consumption')
    ylabel('Energy consumption(MJ)')
    legend('ORE', 'WASTE', 'TOTAL')
    %----------------------------------------------------------------------
    subplot(2,3,6)%Figure6
    gwp   = diag([ore_GWP waste_GWP total_GWP]);
    GWP   = bar(gwp,'stacked');
    title('Global warming potential')
    ylabel('GWP(t CO2 eq)')
    legend('ORE', 'WASTE', 'TOTAL')

and the figure is presented below

How to make Figure 2 and Figure 3 share a common legend, and place the legend below the middle of the two figures

After that, how to make the numbers of the pie chart do not overlap and display more clearly

Thanks in advance for your help!

Answer 1

[Chunru]

Adjust the parameters if necessary. The plot in this web livescript is for illustration only.

subplot(232); pie([51 2 45 2]);
subplot(233); pie([24 6 30 40]);
h = legend('drill', 'blast', 'load', 'haul');
h.Location = "south";
h.FontSize = 6;
h.Position(1) = .6;
h.Position(3:4) = h.Position(3:4)*.7;   % reduce size if necessary
subplot(234); bar(diag([2 6 8]), 'stacked');
h1 = legend;
h1.FontSize = 6;
h1.Location = "northwest";

[Chao Zhang]

Thanks for your help!

Can i ask a question? is it possible to change the name of 'data1' 'data2' 'data3' 'data4' in the legend to 'drill' 'blast' 'load' 'haul'?

[Chunru]

See above.

Answer 2

[dpb]

legend is limited in its flexibility, unfortunately. A given axis can have only one legend and the second axis/figure "knows nuthink!" about the other so there's not any way to refer to the properties of the other from whichever one you choose to add the legend to.

The new tiledlayout has shared title and axes labels properties, but not, again, the legend.

The best I can think of would entail drawing the area for the legend by fitting in another subplot into the mix and creating a dummy figure with the various colors assigned but all data NaN so only the legend would end up being visible. Whether you can create enough room in the right place without squishing everything else too much and leaving a bunch of empty space on the left third is, I expect, doubtful.

I just don't see much way to manage what you want.

HINT: Using the 'location','best' pair will go a long ways on your barplots to avoid the data with those legends.

Read through the doc for legend carefully for all the available properties to see what options are for placement and orientation.

As for the pie label placement, the pie chart returns an array of handles to the patch and text objects; the even-numbered ones in the array are those of the labels; you can modify the .Position property to suit.

[Chao Zhang]

Thanks for your help!