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Sysquake Pro – Table of Contents

Sysquake – Table of Contents

Sysquake for LaTeX – Table of Contents

Interactivity Functions

Interactive figures defined in SQ files and SQ scripts rely on special functions which describe precisely which element the user maniulates and where. For more informations, you should read the chapters SQ Files References and SQ Script References.

firstrun

Determine whether the SQ script is run for the first time.

Syntax

b = firstrun

Description

firstrun returns true if the SQ script is run for the first time after loading or reset, or false otherwise. For SQ scripts with interactive graphics, it should be used to give an initial value to variables which can later be manipulated by the user.

firstrun must not be used in SQ files.

Example

The following SQ script initializes variable x only once to random values; then the user can manipuate each point interactively.

if firstrun
  x = rand(1,10);
end
if _id == 1
  x(_ix) = _y1;
end
plot(1:10, x, '', 1);

_dx _dy _dz

Displacement between current and previous position during a manipulation.

Syntax

dx = _dx
dy = _dy
dz = _dz

Description

When the button of the mouse is held down, _dx gives the horizontal displacement from the previous to the current position of the mouse; it is equivalent to _x1-_x. _dy give the vertical displacement. _dz give both displacements as a complex number.

See also

_x, _y, _y, _x1, _y1, _y1, _kx, _ky, _kz

_id

ID of the manipulated graphics object.

Syntax

n = _id

Description

When a graphics object drawn with an ID argument larger than zero is manipulated with the mouse, _id gives its ID; in all other cases, _id is the empty array [].

Example

if firstrun
  y = 3;
  x = 2;
end
switch _id
  case 1
    % the horizontal line is being manipulated
    y = _y1;
  case 2
    % the vertical line is being manipulated
    x = _x1;
end
line([0,1], y, 'b', 1);
line([1,0], x, 'r', 2);

_ix

Index of the manipulated graphical element.

Syntax

n = _ix

Description

When a graphical object drawn with an ID argument larger than zero is manipulated with the mouse, _ix gives the index of the point being manipulated; in all other cases, _ix is the empty array [].

Example

if firstrun
  y = rand(1,10);
end
if ~isempty(_ix)
  y(_ix) = _y1;
end
plot(y, 'g', 1);

_kx _ky _kz

Ratio between current and previous position during a manipulation.

Syntax

kx = _kx
ky = _ky
kz = _kz

Description

When the button of the mouse is held down, _kx gives the ratio between the horizontal position of the mouse and the previous horizontal position; it is equivalent to _x1/_x. _kx is typically used to change a scale or a gain. _ky does the same vertically, and _kz for both directions as a complex number.

Example

if firstrun
  num = 1;
  den = [1,2,3,4];
end
if ~isempty(_ky)
  % change the gain of the transfer function num/den
  num = _ky * num;
end
step(num,den,'b',1);

See also

_x, _y, _z, _x1, _y1, _z1, _dx, _dy, _dz

_nb

Number of the manipulated trace.

Syntax

n = _nb

Description

When a graphical object drawn with an ID argument larger than zero is manipulated with the mouse, _nb gives the number of the trace being manipulated; in all other cases, _ix is the empty array [].

Example

if firstrun
  Y = rand(5,10);
end
if ~isempty(_nb)
  Y(_nb,_ix) = _y1;
end
plot(Y, 'b', 1);

_m

State of the Shift key during a manipulation.

Syntax

b = _m

Description

During a manipulation with the mouse, _m is true if the Shift key is held down or false otherwise.

_q

Plot-specific value.

Syntax

q = _q

Description

When a graphical object drawn with an ID argument larger than zero is manipulated with the mouse, _q gives a value which depends on the graphics; in all other cases, _ix is the empty array []. Not all graphics define a value for _q.

Example

Root locus where the closed-loop and open-loop poles may be manipulated:

if firstrun
  % define an initial transfer function
  num = -1;
  den = 1:4;
end
switch _id
  case 1
    % gain change
    num = num * _q;
  case 2
    % new location of open-loop poles
    den = movezero(den, _z0, _z1);
end
scale('equal',[-3,1,-2,2]);
sgrid;
% root locus for a gain >= 0
rlocus(num,den,'r',1);
% closed-loop poles on the root locus
plotroots(addpol(num,den),'^',1);
% open-loop poles (gain=0)
plotroots(den, 'x', 2);

_rho _theta

Mouse position in polar coordinates when the button was pressed.

Syntax

rho = _rho
theta = _theta

Description

When the button of the mouse is held down, _rho and _theta give the position at the instant when the button was pressed in polar coordinates, i.e. _rho is sqrt(_x^2+_y^2) and _theta is atan2(_y,_x). In all other cases, they return the empty array [].

See also

_x, _y, _z, _rho0, _theta0, _rho1, _theta1

_rho0 _theta0

Initial position of the object being manipulated in polar coordinates.

Syntax

rho = _rho0
theta = _theta0

Description

When the button of the mouse is held down over a graphical object drawn with an ID argument larger than zero, _rho0 and _theta0 give its initial position in polar coordinates, i.e. _rho0 is sqrt(_x0^2+_y0^2) and _theta0 is atan2(_y0,_x0). In all other cases, they return the empty array [].

See also

_x0, _y0, _z0, _rho, _theta, _rho1, _theta1

_rho1 _theta1

Current position of the mouse in polar coordinates during a manipulation.

Syntax

rho = _rho1
theta = _theta1

Description

When the button of the mouse is held down, _rho and _theta give the current position of the mouse in polar coordinates, i.e. _rho1 is sqrt(_x1^2+_y1^2) and _theta1 is atan2(_y1,_x1). In all other cases, they return the empty array [].

See also

_x1, _y1, _z1, _rho0, _theta0, _rho, _theta

_v

Values of SQ variables.

Syntax

v = _v

Description

In a handler, _v gives a structure whose fields contain the value of SQ variables.

_x _y _z

Mouse position when the button was pressed.

Syntax

x = _x
y = _y
z = _z

Description

When the button of the mouse is held down, _x gives the horizontal position at the instant when the button was pressed; in all other cases, _x is the empty array []. _y gives the vertical position; _z gives the horizontal and vertical position as a complex number.

Example

% define a region where the user can click
scale([0,10,0,10]);
if ~isempty(_x)
  % draws a line between the mousedown position
  %  and the current position
  plot([_x,_x1],[_y,_y1]);
end

See also

_x0, _y0, _z0, _x1, _y1, _z1

_x0 _y0 _z0 _p0

Initial position of the object being manipulated with the mouse.

Syntax

x = _x0
y = _y0
z = _z0
p = _p0

Description

When the button of the mouse is held down over a graphical object drawn with an ID argument larger than zero, _x0 gives its initial horizontal position; in all other cases, _x0 is the empty array []. _y0 gives the vertical position; _z0 gives the horizontal and vertical position as a complex number; and _p0 gives the position as a 2D vector for 2D graphics and as a 3D vector for 3D graphics.

See also

_x, _y, _z, _x1, _y1, _z1, _p1

_x1 _y1 _z1 _p1

Current position of the mouse during a manipulation.

Syntax

x = _x1
y = _y1
z = _z1
p = _p1

Description

When the button of the mouse is held down, _x1 gives the current horizontal position of the mouse; otherwise (when the button is up), _x1 is the empty array []. _y1 gives the vertical position; _z1 gives the horizontal and vertical position as a complex number; and _p1 gives the position as a 2D vector for 2D graphics and as a 3D vector for 3D graphics, using the associated surface set by sensor3.

See also

_x0, _y0, _z0, _p0, _x, _y, _z, sensor3