Plotting method for objects of class `OF_array`

as produced
by the `farneback`

function.

```
# S3 method for OF_array
plot(x, gridsize = c(25, 25), thresh = 0,
add = TRUE, arrow.ex = 0.05, xpd = TRUE, ...)
```

## Arguments

x |
An object of class `OF_array` . |

gridsize |
A 2-element vector indicating the number of optical flow
vectors to plot in each x-y dimension (default: c(25, 25)). Alternatively, a
numeric value that will be used for both dimensions. |

thresh |
The minimal length of optical flow vectors that should be
plotted (default: 0). |

add |
A logical indicating whether to plot the vector field over an
existing plot (default: FALSE). |

arrow.ex |
Controls the length of the arrows. The length is in terms of
the fraction of the shorter axis in the plot. So with a default of .05, 20
arrows of maximum length can line up end to end along the shorter axis. |

xpd |
If true does not clip arrows to fit inside the plot region,
default is not to clip. |

... |
Graphics arguments passed to the `arrows` function that
can change the color or arrow sizes. See help on this for details. |

## See also

## Author

Simon Garnier, garnier@njit.edu

## Examples