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OPEN DISPLAY MONITOR

To see any of the visual outputs of GRASS, one must first begin by diplaying a monitor. As usual in GRASS, it may be done either by using the Display Manager or by entries at the command prompt in the Bash terminal.

The technical documentation for the control of monitors is that for GRASS module d.mon.

We will first open a monitor using the Display Manager.

Before we do this, the user must be cautioned that the red "X" in the upper corner of a monitor must NOT be used to close a monitor. This will take a bit of "getting-used-to" by Windows users.

In the Display Manager, start display monitor x0, by clicking menu items in this order: Display => Start displays => x0

x0

By clicking on the blue top bars and dragging, your desktop would look much like this:

x0
CLICK TO ENLARGE

You may note that our having used A Kinder, Gentler Bash Screen on the WinGRASS for the GREEN website, also makes the display monitors come up with a white background.

If you are running GRASS 6.1, for displays x0 through x6, we could have accomplished the above another simpler way by merely left-clicking on the "x0" button at the left end of the third row on the heading of the Display Manager. However, this is a new feature and may not yet be stable.

In the Display Manager, stop display monitor x0, by clicking menu items in this order:
Display => Stop displays => x0

It is possible to simultaneously exit completely out of GRASS and simultaneously close all open display monitors by entering "exit" at the command prompt in the Bash window, and pressing Enter, but it is best to close the monitors individually using menu choices.

We will now use the Bash command line to open display monitor x0.

At the command prompt, type
d.mon
and press Enter

bash

The d.mon graphical screen will appear:

d.mon

This is the screen that you could have obtained from the Display Manager menu by clicking on:
Display => Manage displays
and it will operate exactly the same, however you accessed it.

Click (and hold) on the slider bar on the right and pull it down to the bottom.
Click on the button for "List all monitors (with current status)"
Click on the "Run" button.
The following listing will appear. This is a cropped version obtained after clicking on the "resize (middle) button" at the top right:

We really did not need this listing simply to start a single monitor, but when you have a number of monitors open, this listing will be useful to let you know what is available.

If you have clicked on the middle (resize) button on the upper right in order to see the full list of available monitors, click on it again to return it to its normal smaller size.

Use the slider on the right so that you may see the lower part of the screen. The button for "List all monitors (with current status)" is still selected (as indicated by it's button being red rather than gray). Click it again to unselect it (it's button will turn gray). Click the "Clear" button on the bottom. You will see that this only clears the text display area at the bottom. It will not clear any entries you have made in the various entry areas.

Use the slider bar on the right, and slide it up (by click & hold & drag). Most controls for the d.mon graphical screen will be what you are used to in Windows. This is very much different from that which was allowed in the Bash text form we used to enter GRASS.

  • Note that the slider bar worked as one would expect it to work in a Windows program (rather than by right-clicking or left-clicking on it you would do in the Bash window or in a text form).
  • You may move downward (and rightward) in entry fields by pressing Tab. You may move move upward (and leftward) in entry fields by pressing Shift-Tab.
  • You may use the mouse to click on an entry field.
  • You will find that you may clear an entry field by using the delete key or the backspace
  • You may "select" text in an entry field and delete it, or you may type new text which will replace the selected text.
  • If there is text in an entry field, you may use the arrow keys to move to the left or right in that text. Up and down arrows do nothing.

Click on the entry field labelled "Name of the graphical monitor to start (string optional)". Enter:
x0
Note that is x-zero and not x-O.

Press the "Run" button. Display monitor x0 will be displayed and the d.mon screen will look like this:

d.mon

There is no particular need to clear the text field, but we will do it so that you can see that it affects only the text display window and nothing in the entry fields. Press the "Clear" button".

We now want to close display monitor x0.

First we must clear "x0" from the "start" field, because when the "Run" button is pressed, d.mon performs all the items entered in any of the entry fields. Select the text "x0" in the "start" field and delete it, leaving it empty.

Click on the entry field for "Name of graphics monitor to stop (string, optional)"
Enter the text:
x0
Press the "Run" button.
Graphics monitor x0 will be closed.

Click on the "Close" button.
The d.mon graphics screen will be closed.

We have now opened display monitor x0 two different ways:

  • With the Display Manager, and
  • Running the d.mon graphical screen from the Bash command line
We have noted that GRASS 6.1 (not yet a final release, and probably not the best choice for a GRASS newcomer) in the 3rd row of its heading has a button for "x0", which if clicked will start display monitor x0.

There is yet another way to start display monitor x0, perhaps a bit old-fashioned, but a fairly good way to do the job with a few keystrokes.
At Bash command prompt, type
d.mon start=x0
and press Enter
Display monitor x0 will be opened, and the Bash screen will look like this:

To close the monitor using this approach, at the Bash command prompt, type:
d.mon stop=x0
and press Enter
Display monitor x0 will be closed and the Bash screen will look like this:

So we have learned 3 reliable ways to start a diplay monitor, and know about another way that will be available with the next release of GRASS.

In the Display Manager, use menu commands:
File => Exit
The Display Manager will be closed.

In the Bash window, at the command prompt, type:
exit
and Enter
You will have exited WinGRASS.

This page replaces HOW TO OPEN A MONITOR

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