#### 3.2.1.1 Zooming with the mouse ¶

To zoom with using the mouse, put the mouse on the point you want to zoom around. Click the left button to zoom in on this point, or the right button to zoom out. If you drag the mouse between pressing and releasing the button, the point under the mouse when you pressed the button will scroll to the point where you release the button. The middle mouse button does not zoom, but it will scroll if you drag while pressing it. Hence, the left button zooms in, the middle button pans, and the right button zooms out.

If you click just outside the edges of the plot, near the tick marks around the edges of the plot, the zoom and pan operations will involve only the axis you click on. In this way you can zoom in on a region of x (or y) without changing the magnification in y (or x). Or with the middle button, pan along one direction without having to worry about accidentally changing the limits in the other direction slightly.

An alternative way to scroll using the mouse is to hold the shift key and press the left mouse button at one corner of the region you want to expand to fill the screen. Holding the button down, drag the mouse to the opposite corner of your rectangle, then release the button to perform the zoom. This zoom operation is more difficult to control, but it provides single step zooming with unequal x and y zoom factors. (The inverse operation – mapping the current full screen to fill the rectangle you drag out with the mouse – is available with shifted right button. This turns out to be unusably non-intuitive.)

After any mouse zoom function, all four limits are set to fixed values, even if they were extreme values before the zoom. You can restore the pre-zoom limits, including any extreme value settings, by typing:

    unzoom