Button Functions in Mathlets
In the 2-dimensional graphing applets, there are 4 buttons underneath the
displayed graph:
- Zoom In causes the graph to enlarge by a factor of 2, with
the center of the new graph region given by the coordinates of the
next mouse click on the graph (so two clicks are needed, first on the
button, then on the graph).
- Zoom Out causes the graph to reduce by a factor of 2, with
the center of the new graph region given by the coordinates of the
next mouse click on the graph (so two clicks are needed, first on the
button, then on the graph).
- Mouse causes the display to show the coordinates of the
mouse position, in coordinate units -- clicking this button again
turns the display off.
- Bounds causes a pop-up window to appear, showing 6 text input
fields and 4 buttons. The 6 text input fields are:
- xmin:
the left (lower) endpoint of the x-axis
- xmax:
the right (upper) endpoint of the x-axis
- Δx:
the distance (in x-coordinate units) between
hash marks on the x-axis
- ymin: the lower endpoint of the y-axis
- ymax: the upper endpoint of the y-axis
- Δy:
the distance (in y-coordinate units) between
hash marks on the y-axis
Each of these text input fields will accept any decimal number.
The buttons perform the following tasks:
- Square causes the axis settings for the graph to be changed
so that the marked units (determined by delx and dely)
are the same length on both axes, by increasing the number of units
on one axis, as necessary, redrawing the graph and setting the text
input fields to match (but not closing the pop-up window).
- Std causes the standard settings for the
graph (xmin=-10.0, xmax=10.0,
Δx=1.0,
ymin=-10.0, ymax=10.0,
Δy=1.0) to take effect,
redrawing the graph and setting the text input fields to match
(but not closing the pop-up window).
- OK causes the current settings of the values in the text
fields to take effect, redrawing the graph and closing the pop-up window.
- Cancel closes the pop-up window with no further
effect on the
graph.
In the 3-dimensional graphing applets, there are 2 buttons underneath the
displayed graph:
- Bounds -- as above, but
3 additional text input fields are available:
- zmin: the lower endpoint of the z-axis
- zmax: the upper endpoint of the z-axis
- Δz:
the distance (in z-coordinate units) between
hash marks on the z-axis
The buttons available in this pop-up window are a bit different, too:
- Square is not available.
- Apply causes the current settings of the values in the text
fields to take effect (but not closing the pop-up window).
- View/Grid
causes a pop-up window to appear, showing 4 text input
fields and 5 buttons. The 4 text input fields are:
- a: (View Angle) specifies first viewing angle, measured
counterclockwise in xy-plane, in degrees.
- b: (View Angle) specifies second viewing angle, measured
down from z-axis, in degrees.
- xgrid: graph grid spacing in x direction
- ygrid: graph grid spacing in y direction
Each of these text input fields will accept any decimal number.
The buttons perform the following tasks:
- Enter View Point causes another pop-up window
to appear, showing 3 text input fields and two buttons.
The 3 text input fields are x, y, and z, the
coordinates of a point in space. The OK button computes
the view angles a and b (see above), enters them into
the corresponding fields in the previous pop-up window, and closes
this pop-up window -- the effect is that the graph is rotated so that
it is shown as though seen from the point (x,y,z)
in space.
The Cancel button closes the pop-up window with no
effect on the graph.
- Std causes the standard settings for the
graph (a=45, b=45, xgrid=1.0,
ygrid=1.0)
to take effect,
redrawing the graph and setting the text input fields to match
(but not closing the pop-up window).
- Apply causes the current settings of the values in the text
fields to take effect (but not closing the pop-up window).
- OK causes the current settings of the values in the text
fields to take effect, redrawing the graph and closing the pop-up window.
- Cancel closes the pop-up window with no
further effect on the graph.
There are a few applet-specific differences:
- In cylindrical coordinates, the grid
values in the View/Grid pop-up window are
specified as rgrid and
θgrid
- In
spherical coordinates,
the grid values in the View/Grid pop-up window
are specified as θgrid and
φgrid
- In
parametric surfaces,
the grid values in the View/Grid pop-up window
are specified as
sgrid and tgrid
- In several 3-D applets (parametric paths;
points, lines, and vectors;
vector fields), the xgrid and
ygrid fields are unnecessary, and are therefore not supported.
- In the 2-D applets with two separate graphs
(Jacobians, integration by parts,
and substitution 1 and 2),
the second graph uses coordinates
u and v instead of x and y, so the fields
in the pop-up window brought up by the Bounds button for the
second graph are marked by umin, umax,
Δu, vmin, vmax, and
Δv.
- In sequences and series,
only 5 text input fields
are available in the Bounds pop-up window:
nmin (minimum value of n --
maximum value is nmin+100), Δn
(distance between hash marks
on the horizontal axis), ymin,
ymax,
and Δy.