vectors - creates a metafile of vectors, markers, and labels from a

vectors - Creates a metafile of vectors, markers, and labels from a vectors dataset

SYNOPSIS

vectors  [ parameter=value ... ]  [ inputfile outputfile ]
vectors  [ parameter=value ... ]  [ inputfile ... directory ]

Parameters are: master_file, vector_type, from-dir, vector_vars, wind_barbs, scale_factor, draw_lines, draw_markers, label_vars, label_where, decimal_places.

DESCRIPTION

The function vectors creates a metafile of vectors from input datasets containing any of the following types of data:

vector_type=latlon: Vector magnitude and direction are determined from variables named delta_lat and delta_lon. Units for these two variables are assumed to be degrees.; 1) Parallel variables (latitude, longitude, delta_lat, delta_lon).; 2) Parallel 2-D variables (delta_lat, delta_lon) with computable earth location.

vector_type=northeast: Vector magnitude and direction are determined from two user-specified variables defining north and east components.; 1) Parallel variables (latitude, longitude, north, east).; 2) Parallel 2-D variables (north, east) with computable earth location.

vector_type=magphase: Vector magnitude and direction are determined from two user-specified variables defining magnitude and phase, or heading, angle. Heading is measured clockwise from due north.; 1) Parallel variables (latitude, longitude, magnitude, phase).; 2) Parallel 2-D variables (magnitude, phase) with computable earth location.

vector_type=complex: Vector magnitude and direction are determined from one user-specified variable which contains both north and east components.; 1) Parallel variables (latitude[*], longitude[*], northeast[2,*]), where northeast[1,*] is the north component and northeast[2,*] is the east component.; 2) Single 3-D variable northeast, with computable earth location, where northeast[1,*] is north componennt and northeast[2,*] is the east component.

The convec function converts between any of the above types of vector data.

Vectors can be generated as arrows or as wind barbs. Vector origins can be highlighted with markers, and can be labelled with the values of one or more input variables.

PARAMETERS

master_file

This is the name of the master dataset used to specify the region for which a metafile will be produced. See master for information on generating master datasets.

Valid responses are any TeraScan dataset that contains an earth transform. The default is Master.

vector_type

The vector types supported are decribed above. Valid responses are [latlon, northeast, magphase, complex]. The default is latlon.

from_dir

OPTIONAL. If from_dir=yes, then vector direction is assumed to be 'from' rather than 'to'. For example, if from_dir=yes, (speed, dir) coordinates (2,45) correspond to (north, east) coordinates (-1.414, -1.414); the vector is treated as it were coming 'from' the northeast, going to the southwest. If from_dir=no, (speed, dir) coordinates (2,45) correspond to (north, east) coordinates (1.414, 1.414). from_dir only applies when vector_type=magphase. The default is from_dir=yes, which is most appropriate when working with wind vectors; e.g., a north wind blows from the north.

vector_vars

Specifies the (north, east) variables if vector_type=northeast. Specifies the (magnitude, phase) variables if vector_type=magphase. Specifies the (northeast) variable is vector_type=complex. This parameter is not used if vector_type=latlon. There is no default.

wind_barbs

Specifies whether or not to draw wind barbs. Valid responses are [yes, no]. The default is no, which means that the output will be arrows. This parameter is not used when vector_type=latlon,

scale_factor

If wind_barbs=no, this parameter defines the length of vectors in terms of pixels per unit. If wind_barbs=yes, this parameter defines the flag size relative to the default (40 pixels).

A valid response is any non-zero real value; a negative value will invert the vectors. There is no default.

draw_lines

OPTIONAL. Specifies whether or not to connect the vector origins with lines. This parameter must be specified on the command line. Valid responses are [yes, no]. The default is no.

draw_markers

Specifies whether or not to place a marker at the origin of each vector. Valid responses are [yes, no]. The default is yes.

label_vars

Specifies the variable(s) to be labelled near the origins of the vectors. Valid responses are any variable names. The default is none.

label_where

Specifies the location of the label relative to the origin of each vector. Valid responses are [above, below, right, left, best]. The default is below. If label_where=best, a label is placed either below or above a given vector origin so the label does not interfere with the vector.

decimal_places

Specifies the number of decimal places to be displayed when posting real variable values. The valid range is [0, 10]. The default is 1.

EXAMPLES

lapaz% vectors
in/out files   : char(255) ? n12.points n12.meta
master_file    : char(255) ? [Master] n12.93201.0221
vector_type    : char(  9) ? [latlon]
draw_markers   : char(  3) ? [no] yes
label_vars     : char(127) ? []
lapaz%

NOTES

The tovsproc and t1edr functions produce output suitable for working with vectors.

tovsproc output datasets includes (wind_speed, wind_dir) at multiple elevations. t1edr output datasets includes (geos_wind_north, geos_wind_east) and (thrm_wind_north, thrm_wind_east) at multiple elevations.

These variables must be burst along their elevation dimension in order to be processed by vectors. See burst.

Last Update: $Date: 1999/05/10 20:46:56 $