Plot 2D vector field

Hi

I have a table T of four columns x,y,u,v,

where x and y are the coordinates

and u and v are the values of the x and y components, respectively.

Thus, T represents a two-dimensional vector field.

For example, let

T=

1 3 -1 -1

1 4 0.500000000000000 -0.500000000000000

2 3 -0.250000000000000 0.250000000000000

2 4 0.100000000000000 0.100000000000000

I want to plot a 2-D vector field from this table!!!

I tried using the function:

coneplot(T)

but became the following error message:

??? Error using ==> coneplot>parseargs at 365

Wrong number of input arguments.

Error in ==> coneplot at 64

[x y z u v w cx cy cz s color quiv method nointerp] =

parseargs(nargs,args);

It seems that coneplot works only for 3-D.

Can someone tell me how to change this command line?

Thank you

Emerson

[Qiujie Meng]

Hello , Emerson De Souza:

This is my code:

%%%%%%%%%%%%%%%%%%

close all;clc;clear all;

velocity=load('velocity100POINTS.txt');

x=velocity(:,1);

y=velocity(:,2);

u=velocity(:,3);

v=velocity(:,4);

figure

quiver(x,y,u,v)

%%%%%%%%%%%%%%%%%%%%%

Although my file has vectors,why the figure is like that......?

Answer 1

[Walter Roberson]

Sounds like you are looking for quiver

[Emerson De Souza]

Thanks Walter,

yes, it works.

I first did the following:

>> x=T(:,1);

>> y=T(:,2);

>> u=T(:,3);

>> v=T(:,4);

and finally plot with

quiver(x,y,u,v)

But is there a way to plot directly from table T

without needing to define new variables x,y,u,v?

Thanks in advance for your attention

Emerson

[Walter Roberson]

quiver(T(:,1),T(:,2),T(:,3),T(:,4))

[Emerson De Souza]

Thank you Walter

Wish you a nice night

Emerson

Answer 2

[Brijesh]

clc
clear all
syms x y
f = input('Enter:');

Unable to run the 'fevalJSON' function because it calls the 'input' function, which is not supported for this product offering.

p = inline(vectorize(f(1)),x,y);
q = inline(vectorize(f(2)),x,y);
x = linspace(-1,1,10);
y = x;
[X, Y] = meshgrid(x,y);
U = p(X,Y)
V = q(X,Y)
quivert(X,Y,U,V,1)
axis on;

[Dyuman Joshi]

@Brijesh, how exactly does your answer answers the question asked, that too 12 years ago and with an accepted answer.

There is no function as quivert and using inline and vectorize is not recommended.