Demo window 1. My first Demo window script

The Demo window is Praat’s least visible window: you can create it only through a script. Try the following script after selecting a Sound object:

`demo Draw: 0, 3, -1, 1, “yes”, “curve”
`

You see the Demo window turn up on the screen, with the Sound painted into it. It works because the Draw... command is available in the Objects window when you select a Sound. Then try:

`demo Draw line: 0, -1, 3, 1
`

You see a line drawn from (0 seconds, -1 Pa) to (3 seconds, +1 Pascal) in the waveform. It works because the Draw line... command is available in the Picture window. Then try:

`demo Erase all
` `demo Red
` `demo Axes: 0, 100, 0, 100
` `demo Text: 50, “centre”, 50, “half”, “Hello”
`

You see a text appear in red, in the centre of the window. This works because you are using commands from the Picture window, including the Axes... command, which sets the world coordinates to something else than before (before, the world coordinates were determined by the Sound).

Now suppose you want the Sound to appear in the top half of the window, and some texts in the bottom left and bottom right corners of the window. You can use Select outer viewport... and Select inner viewport..., if you know that the size of the Demo window is “100” horizontally and “100” vertically (rather than 60×60 inch, as the Picture window), and that the point (0, 0) lies in the bottom left (rather than the top left, as in the Picture window):

`demo Erase all
` `demo Black
` `demo Times
` `demo 24
` `demo Select outer viewport: 0, 100, 50, 100
` `demo Draw: 0, 0, 0, 0, “yes”, “curve”
` `demo Select inner viewport: 0, 100, 0, 100
` `demo Axes: 0, 10, 0, 10
` `demo Text: 0, “left”, 0, “bottom”, “Left bottom corner”
` `demo Text: 10, “right”, 0, “bottom”, “Right bottom corner”
`

As the title page of a presentation, you could do:

`demo Erase all
` `demo Select inner viewport: 0, 100, 0, 100
` `demo Axes: 0, 100, 0, 100
` `demo Paint rectangle: “purple”, 0, 100, 0, 100
` `demo Pink
` `demo Text: 50, “centre”, 50, “half”, “This is my title”
`

### Links to this page

- Demo window