MANIPULATING THE
DEVICES
- manipulation of the X-11 graphic devices in Xi -
In the previous examples we used the X-graphic device without using
any manipulating functions. Let's return to our beginning example. We want
to compare the Sine and Cosine function. Instead of putting two plots
together in a single device like in the first example we can also open up
two devices. We begin in the same way as in example 1. First subdivide the
interval -10 to 10 into 500 pieces and calculate the Sine:
( 1)>x=interval(-10,10,500);
( 2)>y=sin(x);
Now open up the first X-device and plot the sine:
( 3)>window(0);
( 4)>plot(x,y,\yrange={-1,1},\xtitle="x",\ytitle="y",\line);
Instead of putting a title above the plot we now change the title of the
X-window:
( 5)>window(\title="The Sine function");
Let's calculate the Cosine
( 6)>y=cos(x);
open up the second X-device
( 7)>window(1);
plot the Cosine function inside
( 8)>plot(x,y,\yrange={-1,1},\xtitle="x",\ytitle="y",\line);
and finally change the title of that new X-window:
( 9)>window(\title="The Cosine function");
The sizes and positions are not very satisfactory yet. Let's move and
resize them (perhaps your mouse is tired :-). We begin with the first
window:
( 10)>window(0,\position={10,10},\size={400,400});
Next the second window:
( 11)>window(1,\position={410,10},\size={400,400});
Now where we've played enough with the X-device, we should close both windows
and start something new:
( 12)>window(0,\close);
( 13)>window(1,\close);
We want two ppm-files of the above plots. Let's open a PPM-defice with
500x500 pixels:
( 14)>window(0,\size={500,500},\ppm);
Calculate and plot the Sine function:
( 15)>y=sin(x);
( 16)>plot(x,y,\yrange={-1,1},\xtitle="x",\ytitle="y",\line);
Now that we have the whole plot - let's save it. First we have to
choose a good name for the file:
( 17)>window(0,\name="sine.ppm",\ppm);
Note that here the ppm argument has to be set too (this will be possibly
changed some time).
The file will be automatically saved when the device is closed:
( 18)>window(0,\close);
And the same with the Cosine:
( 19)>window(0,\name="cosine.ppm",\size={500,500},\ppm);
( 20)>y=cos(x);
( 21)>plot(x,y,\yrange={-1,1},\xtitle="x",\ytitle="y",\line);
( 22)>window(0,\close);
Of course all the action mentioned can be done with the mouse and the
suitable buttons on the X-window too.
© 1995 by Bodo Junglas, Klaus Spanderen and Fabian Weis
- Last revised: April 23 1996