Function Functions (Mathematics)

Mathematics

Plotting Mathematical Functions

The fplot function plots a mathematical function between a given set of axes limits. You can control the x-axis limits only, or both the x- and y-axis limits. For example, to plot the humps function over the x-axis range [-5 5], use

```
fplot(@humps,[-5 5])
grid on
```

You can zoom in on the function by selecting y-axis limits of -10 and 25, using

```
fplot(@humps,[-5 5 -10 25])
grid on
```

You can also pass an inline for fplot to graph, as in

```
fplot(inline('2*sin(x+3)'),[-1 1])
```

You can plot more than one function on the same graph with one call to fplot. If you use this with a function, then the function must take a column vector x and return a matrix where each column corresponds to each function, evaluated at each value of x.

If you pass an inline object of several functions to fplot, the inline object also must return a matrix where each column corresponds to each function evaluated at each value of x, as in

fplot(inline('[2*sin(x+3), humps(x)]'),[-5 5])

which plots the first and second functions on the same graph.

Note that the inline

```
f= inline('[2*sin(x+3), humps(x)]')
```

evaluates to a matrix of two columns, one for each function, when x is a column vector.

```
f([1;2;3])
```

returns

   -1.5136   16.0000
   -1.9178   -4.8552
   -0.5588   -5.6383

Representing Functions in MATLAB Minimizing Functions and Finding Zeros