xarrows

Scilab Function
Last update : April 1993

xarrows - draw a set of arrows

### Calling Sequence

  `xarrows(nx,ny,[arsize,style])`

### Parameters

- `nx,ny`: real vectors or matrices of same size.
- `arsize`: real scalar, size of the arrow head. The default value can be obtained by setting arsize to -1.
- `style`: matrix or scalar. If `style` is a positive scalar it gives the color to use for all arrows. If it is a negative scalar then the current color is used. If it is a vector `style(i)` gives the color to use for arrow `i`.

### Description

`xarrows` draws a set of arrows given by `nx` and `ny`. If `nx` and `ny` are vectors, the ith arrow is defined by `(nx(i),ny(i))-->(nx(i+1),ny(i+1))`. If `nx` and `ny` are matrices:

    nx=[xi_1 x1_2 ...; xf_1 xf_2 ...]
    ny=[yi_1 y1_2 ...; yf_1 yf_2 ...]

the `k` th arrow is defined by `(xi_k,yi_k)-->(xf_k,yf_k)`.

`xarrows` uses the current graphics scale which can be set by calling a high level drawing function such as `plot2d`.

### Examples

    x=2*%pi*(0:9)/8;
    x1=[sin(x);9*sin(x)];
    y1=[cos(x);9*cos(x)];
    plot2d([-10,10],[-10,10],[-1,-1],"022")
    xset("clipgrf")
    xarrows(x1,y1,1,1:10)
    xset("clipoff")

### Author

J.Ph.C.