# velocity: Ocean currents velocities In satin: Visualisation and Analysis of Ocean Data Derived from Satellites

 velocity R Documentation

## Ocean currents velocities

### Description

Calculate ocean current speed and direction from eastward and northward components (Copernicus data).

### Usage

```velocity(u, v, depth = 1)
```

### Arguments

 `u` a satin object with eastward ocean current velocities (in m/s). `v` a satin object with northward ocean current velocities (in m/s). `depth` an integer referring to a depth level.

### Details

This function calculates the resulting velocity vectors in the same way as the `"quiver"` function. In addition, these values are returned togheter with their direction in degrees.

### Value

A list with 2 elements, “speed” and “rhumb”, both of class `"satin"`. The former contains the resulting velocity vectors as drawn by `"quiver"`, while the second their direction in degrees.

### Author(s)

Héctor Villalobos

### Examples

```if(interactive()){
# import copernicus data with potential temperatures and ocean current velocities

vel <- velocity(u = oc\$uo, v = oc\$vo)

# Plots overlaying velocity vectors
plot(vel\$speed)
quiver(u = oc\$uo, v = oc\$vo, main = "", length=0.02, scale = 0.7, add2map = TRUE)

plot(vel\$rhumb, col.sep = 90, scheme = c('#d7301f', '#fc8d59','#fdcc8a', '#fef0d9'))
quiver(u = oc\$uo, v = oc\$vo, main = "", add2map = TRUE)
}
```

satin documentation built on Sept. 23, 2022, 1:06 a.m.