How to Draw ErrorBar

Origin : http://jingyan.baidu.com/article/636f38bb7079f4d6b84610f0.html

Matlab: http://blog.sina.com.cn/s/blog_66d362d70102v4i5.html

errorbar

Plot error bars along curve

GUI Alternatives

To graph selected variables, use the Plot Selector in the Workspace Browser, or use the Figure Palette Plot Catalog. Manipulate graphs in plot edit mode with the Property Editor. For details, see "Plotting Tools — Interactive Plotting" in the MATLAB Graphics documentation and "Creating Graphics from the Workspace Browser" in the MATLAB Desktop Tools documentation.
Syntax

errorbar(Y,E)
errorbar(X,Y,E)
errorbar(X,Y,L,U)
errorbar(...,LineSpec)
h = errorbar(...)

Description

Error bars show the confidence intervals of data or the deviation along a curve.

errorbar(Y,E) plots Y and draws an error bar at each element of Y. The error bar is a distance of E(i) above and below the curve so that each bar is symmetric and 2*E(i) long.

errorbar(X,Y,E) plots Y versus X with symmetric error bars 2*E(i) long. X, Y, E must be the same size. When they are vectors, each error bar is a distance of E(i) above and below the point defined by (X(i),Y(i)). When they are matrices, each error bar is a distance of E(i,j) above and below the point defined by (X(i,j),Y(i,j)).

errorbar(X,Y,L,U) plots X versus Y with error bars L(i)+U(i) long specifying the lower and upper error bars. X, Y, L, and U must be the same size. When they are vectors, each error bar is a distance of L(i) below and U(i) above the point defined by (X(i),Y(i)). When they are matrices, each error bar is a distance of L(i,j) below and U(i,j) above the point defined by (X(i,j),Y(i,j)).

errorbar(...,LineSpec) uses the color and line style specified by the string 'LineSpec'. The color is applied to the data line and error bars. The linestyle and marker are applied to the data line only. See linespec for examples of styles.

h = errorbar(...) returns handles to the errorbarseries objects created. errorbar creates one object for vector input arguments and one object per column for matrix input arguments. See errorbarseries properties for more information.

When the arguments are all matrices, errorbar draws one line per matrix column. If X and Y are vectors, they specify one curve.
Examples

Draw symmetric error bars that are two standard deviation units in length:
X = 0:pi/10:pi;
Y = sin(X);
E = std(Y)*ones(size(X));
errorbar(X,Y,E)

Plot the computed average traffic volume and computed standard deviations for three street locations over the course of a day using red 'x' markers:
load count.dat;
y = mean(count,2);
e = std(count,1,2);
figure
errorbar(y,e,'xr')