Subplot: Title length size and main title

Question

Based on the above subplot:

1) I want to be able to have one main title at the top position which represents the title of all the subplots.

2) I would like to increase the length of the title of each subplot such that the length of the title can be extended as the length of the figure in X-direction.

About the figure: I am using this title within the loop which runs 3 times:

CO2_label={'Normal CO2','CO2 with 0.1% NPs','CO2 with 0.5% NPs','CO2 with 1% NPs';'-b','-r','-g','-k'};

for i=1:3
    .
    .
    .
    title(['Area where saturation due to ',CO2_label(1,4),' > saturation due to ',CO2_label(1,i)],'Fontweight','Bold')

end

Answer 1

1) SUPLABEL is the File Exchange submission you can use for the main title. You can also apply x and y labels for a group of subplots.

2) use curly brackets in title call to get strings, not cells:

title(['Area where saturation due to ',CO2_label{1,4},...
       ' > saturation due to ',CO2_label{1,i}],'Fontweight','Bold')