MATLAB Function Reference
errorbar

Plot error bars along a curve

Syntax

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

errorbar('v6',...)
```

Description

Error bars show the confidence level 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) ``` draws the error bars using the line type, marker symbol, and color specified by `LineSpec`.

```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.

Backward Compatible Version

```hlines = errorbar('v6',...) ``` returns the handles of line objects instead of errorbarseries objects for compatibility with MATLAB 6.5 and earlier.

Remarks

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)

```

`LineSpec`, `plot`, `std`