drawVector- draws 2D or 3D vectors from specified points

Draws 3 arrows representing the basis vectors of an R3 coordinate system

drawVector - draws 2D or 3D vectors from specified points

drawOrdinates - draws 3 arrows representing the basis vectors of an R3 coordinate system

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drawVector - is a very simple function to make drawing vectors using the

quiver and quiver3 functions a little more convenient

all this is to prepare the input from xyz triplets or lists of pints and

vectors and pass it into the quiver or quiver3 functions

I was just getting tired of typing it out every time

Syntax:

q=drawVector(points, vectors);

q=drawVector(points, vectors, color);

q=drawVector(points, vectors, color, weigth);

drawVector(points, vectors);

drawVector(points, vectors, color);

drawVector(points, vectors, color, weigth);

Inputs:

points - Nx3 (3D) or Nx2 (2D) matrix; rows correspond to points

if N==1 the same point will be used as origin for all vectors

vectors - Nx3 (3D) or Nx2 (2D) matrix; rows correspond to vectors

color - (optional) string ('r', 'red', etc), RGB triplet or

hexadecimal string; default='red

weight - (optional) scalar setting LineWidth and arrow head size; default=3;

Outputs:

for simple drawing the output does not have to be defined

defining the output, p, saves the graphics element to allow later editing

Example:

% draw 3 red vector arrows from 3 points

% red is the default color

p=[0 0 0; 0 1 1; 2 1 1];

v=[1 1 1; 2 3 -4; 1 0 0];

drawVector(p, v);

axis equal

% draw 3 blue vector arrows from a single point with wider lines

p=[2 1 1];

v=[1 1 1; 2 -3 -1; 1 0 0];

drawVector(p, v, 'blue', 5);

axis equal

% defining the output saves the graphics element and allows for later

% changes to quiver properties

p=[2 1 1];

v=[1 1 1; 2 -3 -1; 1 0 0];

q=drawVector(p, v, 'blue', 5);

axis equal

q.LineStyle='-.';

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drawOrdinates - simple function to draw arrows representing the basis

vectors of any R3 coordinate system

Syntax: drawOrdinates

drawOrdinates(ord, ori)

drawOrdinates(ord, ori, ...)

this is a simple function to draw 3 vectors representing the axes of a

coordinate system

All this really does is prepare the inputs to pass them into the built-in

quiver3 function. I was just tired of typing it out all the time.

Inputs:

ord - ordinates; 3x3 matrix, each column represents one axis as a 1x3

vector. default x, y, z unit vectors at the origin ([1, 0, 0; 0, 1, 0; 0, 0, 1])

ori - origin; 1x3 matrix specifing the coordinates at which to draw;

default [0, 0, 0]

Optional Name-Value pairs

scale - scalar; factor by which to scale the length of each arrow;

default=0

weight - scalar; defines lineweight and arrow head size; default=3

colors - 1x3 list of strings defining colors for each vector;

default=['r', 'b', 'g']);

alternative: 3x3 matrix, where each row defienes one arrow color as

an RGB triplet

Outputs:

no outputs need to be specified

Example 1:

% calling the function without specifying any input will draw 3 unit

% vectors along the x, y, and z axis at the origin

drawOrdinates

Example 2:

% vec=[3, 4, 5]; % start with a random vector

% vec=vec/norm(vec); % normalize

% ord=null(vec); % use null(x) to find 2 orthonormal vectors

% ord=horzcat(vec', ord); % concatenate matrix of orthonormal basis vectors

%

% % draw new ordinates with default settinngs at the origin

% drawOrdinates(ord);

% axis equal

%

% % draw new ordinates centered at [2, 10, 3] with a changed appearence

% drawOrdinates(ord, [2, 10, 3], 'weight', 5, 'scale', 5, 'colors', [0 0 1; 0 0 1; 0 0 1]);

% axis equal