error bar from xlsx

Hello

I have data from excel and I imported and everything going fine except error bar doesn't work

I have an error bar in column 3, this is the first time I use it.

Thank you in advance.

A=importdata('value.xlsx')
x=A.data(:,2)
b=A.data(:,1)
err=A.date(:,3)
S1=plot(x,b,err,'sk','MarkerFaceColor','k')
error(x,b,err)

Answer 1

[Walter Roberson]

The function to plot error bars is errorbar() not error()

[Abdullah Al Alhareth]

A=importdata('value.xlsx')
x=A.data(:,2)
b=A.data(:,1)
err=A.date(:,3)
S1=plot(x,b,err,'sk','MarkerFaceColor','k')
errorbar(x,b,err)

still doesnt work.

[Walter Roberson]

Can you attach your data so we can test?

[Walter Roberson]

Is it correct that you want to load err from a different variable ? x and b are loaded from A.data but err is loaded from A.date -- data compared to date

[Abdullah Al Alhareth]

attached,

also error bar loaded from A data. as well which is the 3rd column.

[Walter Roberson]

What are you expecting when you use plot() to plot three variables? Are you expecting a 3D scatter plot? If so then use plot3() or scatter3()

[Abdullah Al Alhareth]

scatter

I want to know the right code for get the values of error bar from excel and plot it.

[Walter Roberson]

data = readtable('value.xlsx', 'ReadVariableNames',false);
x = data{:,1};
b = data{:,2};
err = data{:,3};
[sx, idx] = sort(x);
sb = b(idx);
serr = err(idx);
plot(sx, sb, 'sk', 'MarkerFaceColor','k');
errobar(sx, sb, serr);

[Abdullah Al Alhareth]

basically I plot x and y from data A which is columns 1 and 2.

Now my error bar in column 3 and I want to use it as an error bar.

[Walter Roberson]

That is what the code I posted does. It takes time to sort the data because your x was not in order, which was leading to lines doubling back on themselves.

[Abdullah Al Alhareth]

Ok , forget about the excel file I uploaded , let’s just do it in the original code which it import data from excel, my error bar is column 3. Which code will be working with it ?

A=importdata('value.xlsx') x=A.data(:,2) b=A.data(:,1) errorbar=A.date(:,3) S1=plot(x,b,errorbar,'sk','MarkerFaceColor','k').

I Tried this one and doesn’t work. keep it as importdata. I want to learn the right code so I can use it for another xlsx files.

Thank you in Advance.

[Walter Roberson]

readtable() is the right code. importdata() is older and fragile, returning different data types depending on whether it finds headers in the file or not.

But if you insist:

filename = 'value.xlsx';
A = importdata('value.xlsx');
x = A.data(:,2);
b = A.data(:,1);
err = A.data(:,3);

[sx, idx] = sort(x);
sb = b(idx);
serr = err(idx);
plot(sx, sb, 'sk', 'MarkerFaceColor', 'k')
errorbar(sx, sb, serr)

The sort() step will not hurt if the data is already sorted, and will help if the data is in the wrong order.

[Abdullah Al Alhareth]

Actually the excel I uploaded it's not the right one, but the data I have all three column It should be in same order, for example if I sorted x then the data will be missed up. That's why.

[Walter Roberson]

filename = 'value.xlsx';
A = importdata('value.xlsx');
x = A.data(:,2);
b = A.data(:,1);
err = A.data(:,3);

plot(x, b, 'sk', 'MarkerFaceColor', 'k')
errorbar(x, b, err)