Help - Vector Specification

Vector Specification explores various notations for two-dimensional vectors including polar, Cartesian components, and navigation.

Click on a region in the image of the default applet display below to read a description of the corresponding feature:

Vector Specification Default Applet Display

Default Applet Display

1. Applet Display Panel

Observe a vector whose magnitude, direction and notation can be varied.

Changing the Vector

When the applet is loaded, it will already display a vector. You can change the vector by:

moving the vector without changing its magnitude or direction by clicking near the middle of the vector and dragging it to a new location
clicking on either the vector's tip or tail and dragging it to a new position
changing the values for one or both of magnitude and direction in the data field in the data entry panel

The two data fields in the control panel display the magnitude of the vector and the angle between the vector and the dotted reference line.

Reference Line

The dotted line is a reference line relative to which the angle specifying the vector's direction is measured. The angle is indicated by an arc drawn between the dotted reference line and the vector.

2. Data Entry Panel

The two data fields show the number pair that specifies the vector's magnitude and direction. Whenever the vector is changed, the data display is updated automatically.

Polar Positive Vector Specification - The vector is specified by its polar coordinates: magnitude and direction angle. The direction angle is taken between the vector and the 'East' direction, indicated by a dotted line. All angles are positive between 0° and 360°, increasing in the positive (counter-clockwise) sense starting at the reference line. The magnitude of the vector is in pixels.

Polar Positive-Negative Vector Specification - The mode is the same as the Polar (positive) mode, except that all angles are measured between -180° and 180°. The angle is negative if the vector points below the horizontal axis, and is positive if the vector points above the horizontal axis. The magnitude of the vector is in pixels.

Navigational Vector Specification - The mode is the same as the Polar (positive) mode, except that angles are taken relative to one of the four compass directions. The choice of compass direction used can be selected from a drop-down menu. All angles range between 0° and 360°. The magnitude of the vector is in pixels.

Cartesian (v_x, v_y) Vector Specification - The vector is specified by its x- and y-components relative to the horizontal x-axis and the vertical y-axis. The x-component is shown in green and the y-component is shown in yellow. The magnitude of the vector is in pixels.

3. Control Button Panel

The applet is controlled by the following buttons.

Icon	Name	Description
	Reset	Clear all settings and start the applet over from its default state.

Last Updated: June 16, 2004