How do I plot with error bars in both directions

Okay, I have two variables, time and temperature. both are 1x10 vector. I also have the error in time and the error in temperature. my time will go on the x axis and the temperature on the y axis. I need to put error bars for the time and temperature points once i have ploted them. I need to do this for various files. So I have recorded them on a text file and done a loop. The errors in the time and temp are also recorded in the txt files. for example in each text file i have the following variables:- row1=time =.......... row2=temp=................. row3=error in time=........... row4=error in temp=.............

I have started like this:-

%Define the file structure

nFiles=500;
filenamePrefix='v';
filenameExtension = '.txt';
 for i=1:nFiles
    filename= [filenamePrefix, int2str(i), filenameExtension];
    tmptimeData=load(filename,'-ascii');
  time{i}=tmptimeData(1,:);
  temp{i}=tmptimeData(2,:);

    figure(i)
    plot(time{i}, temp{i}, 'ro')
    grid on
    hold on
    xlabel('temp')
    ylabel('time')
  end
  clear tmptimeData;

So How would I add the error bars on each of the points which are in the same txt files?

[Adithya Addanki]

Hi MampsRex,

Let me make sure I understand you correctly, you have the time(x) and temperature(y) data along with error in a file.

For error bars, you may use the "errorbar" function. For instance, if you assume time data as "x" and temperature data as "y", you can do this:

x = 1:10;
y = x.*2;
e = std(y)/10*ones(size(x)); % assuming e as error
plot(x,y,'ro')
hold on
errorbar(x,y,e)

http://www.mathworks.com/help/matlab/ref/errorbar.html

Thank you,

Adithya

Answer 1

[Christopher Thissen]

Hi Mamps,

You can use my errorbarxy function to plot error bars in x and y (time and temperature in your case). For your specific example, your code might look like this:

nFiles=500;
filenamePrefix='v';
filenameExtension = '.txt';
 for i=1:nFiles
    filename= [filenamePrefix, int2str(i), filenameExtension];
    tmptimeData=load(filename,'-ascii');
    time{i}=tmptimeData(1,:);
    temp{i}=tmptimeData(2,:);
    dtime{i}=tmptimeData(3,:);
    dtemp{i}=tmptimeData(4,:);
    figure(i)
    plot(time{i}, temp{i}, 'ro')
    errorbarxy(time{i},temp{i},dtime{i},dtemp{i}) 
    grid on
    hold on
    xlabel('temp')
    ylabel('time')
  end
  clear tmptimeData;

Let me know if you need more explanation. - Chris