How to fill between two lines?

Hi, I have been trying to fill between two lines using the fill function with facealpha. However, the plot does not show the shaded area between the two black lines. This is my code and graph currently. I am wanting the standard devation to be shaped and the mean line (red) to be plotted. Thanky for your help!

meanpt=nanmean(pt(:,3:17),2)

means=nanmean(s(:,3:17),2)

%standard deviation

sdpt=nanstd(pt(:,3:17)')

sds=nanstd(s(:,3:17)')

%plot lines

plot(means,meanpt,'r')

hold on

plot(s_std18,pt_std18,'g','Linestyle','--') %plus on estandard deviation

hold on

plot(s_std28,pt_std28,'b','Linestyle','--') %-1std

%add fill between standard deviation lines

inBetween=[pt_std18,fliplr(pt_std28)];

xinBetween=[s_std18,fliplr(s_std28)];

fill(xinBetween,inBetween,'b','Facealpha',0.2)

Answer 1

[Star Strider]

It appears from the nanmean and nanstd calls that the results of ‘meanpt’, ‘means’, and the others are all column vectors, so fliplr would have no effect.

Instead, use:

inBetween=[pt_std18; flipud(pt_std28)];
xinBetween=[s_std18; flipud(s_std28)];

That aside, fill may still have problems with the black lines, since there actually appears to be only one of them. Consider using sort or sortrows on your data first, sorting by the independent variable (x-coordinate) value before processing them further.

[Star Strider]

Rosie Answorth’s Answer became this Comment —

Hi,

I have tired flipud instead of fliplr but the shaded area on my graph is still not showing up. Do you have any ideas what might be causing this? Thank you in advance

meanpt9sc=nanmean(potemp1_all(:,1:23),2)
means9sc=nanmean(salin1_all(:,1:23),2)

%standard deviation
sdpt9sc=nanstd(potemp1_all(:,1:23)')
sds9sc=nanstd(salin1_all(:,1:23)')

%plotting lines mean plus standard deviation and mean minus standard
%deviation
plot(s_std19sc,pt_std19sc,'g','Linestyle','--') %plus one standard deviation
hold on
plot(s_std29sc,pt_std29sc,'b','Linestyle','--') %-1std

%add fill between standard deviation lines
inBetween=[pt_std19sc,flipud(pt_std29sc)];
xinBetween=[s_std19sc,flipud(s_std29sc)];
fill(xinBetween,inBetween,'r','Facealpha',0.2)

%add mean line in red
hold on
plot(means9sc,meanpt9sc,'r')

[Star Strider]

It may be necessary to upload (attach) the data, preferably as a .mat file, so I can work with it.

Note — It is necessary to vertically concatenate the vectors, not norizontally concatenate them. Replace the commas (,) with semicolons (;):

inBetween=[pt_std19sc,flipud(pt_std29sc)];
                     ↑ ← HERE
xinBetween=[s_std19sc,flipud(s_std29sc)];
                     ↑ ← AND HERE

as I originally suggested, and it should work.

If it still has problems, please upload your data.