# ezcontour

(Not recommended) Easy-to-use contour plotter

`ezcontour` is not recommended. Use `fcontour` instead. For more information, see Compatibility Considerations.

## Syntax

``ezcontour(f)``
``ezcontour(f,xyinterval)``
``ezcontour(___,n)``
``ezcontour(ax,___)``
``c = ezcontour(___)``

## Description

example

````ezcontour(f)` plots the contour lines of the function `z = f(x,y)` using the `contour` function. The function plots `f` over the default interval `[-2π 2π]` for `x` and `y`.`ezcontour` automatically adds a title and axis labels to the plot.```

example

````ezcontour(f,xyinterval)` plots over the specified interval. To use the same interval for both `x` and `y`, specify `xyinterval` as a two-element vector of the form `[min max]`. To use different intervals, specify a four-element vector of the form `[xmin xmax ymin ymax]`.```

example

````ezcontour(___,n)` plots using an `n`-by-`n` grid. Use this option after any of the input argument combinations in the previous syntaxes.```
````ezcontour(ax,___)` plots into the axes specified by `ax` instead of the current axes. Specify the axes before any of the input argument combinations in any of the previous syntaxes.```
````c = ezcontour(___)` returns the contour object. Use `c` to modify the contour after it is created. For a list of properties, see Contour Properties.```

## Examples

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This mathematical expression defines a function of two variables, x and y.

`$f\left(x,y\right)=3\left(1-x{\right)}^{2}{e}^{-{x}^{2}-\left(y+1{\right)}^{2}}-10\left(\frac{x}{5}-{x}^{3}-{y}^{5}\right){e}^{-{x}^{2}-{y}^{2}}-\frac{1}{3}{e}^{-\left(x+1{\right)}^{2}-{y}^{2}}$`

The `ezcontour` function requires a function handle argument. Write this mathematical expression in MATLAB® syntax as an anonymous function with handle `f`. You can define an anonymous function in the command window without creating a separate file. For convenience, write the function on three lines.

```f = @(x,y) 3*(1-x).^2.*exp(-(x.^2) - (y+1).^2) ... - 10*(x/5 - x.^3 - y.^5).*exp(-x.^2-y.^2) ... - 1/3*exp(-(x+1).^2 - y.^2);```

Pass the function handle, `f`, to `ezcontour`. Specify a domain from -3 to 3 in both the x-direction and y-direction and use a 49-by-49 computational grid.

`ezcontour(f,[-3,3],49)`

In this particular case, the title is too long to fit at the top of the graph, so MATLAB abbreviates it.

## Input Arguments

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Function to plot, specified as a character vector, string scalar, or function handle to a named or anonymous function.

Specify a function of the form `z = f(x,y)`. The function must accept two matrix input arguments and return a matrix output argument of the same size.

When specifying the function as a character vector or string scalar, array multiplication, division, and exponentiation are always implied. For example, `x^2` is interpreted as `x.^2`.

Example: `'sqrt(x^2 + y^2)'`

When specifying the function as a function handle, use array operators instead of matrix operators for the best performance. For example, use `.*` (`times`) instead of * (`mtimes`).

Example: `@(x,y) sin(x).*cos(y)`

Plotting interval for `x` and `y`, specified in one of these forms:

• Vector of form `[min max]` — Use the interval `[min max]` for both `x` and `y`.

• Vector of form `[xmin xmax ymin ymax]` — Use the interval `[xmin xmax]` for `x` and `[ymin ymax]` for `y`.

Size of the grid, specified as a positive integer. The grid has dimensions `n`-by-`n`.

Axes object. If you do not specify an axes object, then the `ezcontour` uses the current axes.

## Compatibility Considerations

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Not recommended starting in R2016a