#### 9.4.1 Using a Networked Geomview Host

The `Geomview` command looks at the `DISPLAY` or `REMOTEHOST` environment variables to try to determine if you are logged in from another computer. If either of these indicates that you are, `Geomview` will attempt to run Geomview on that computer. In order for this to work, your network must be configured such that the Mathematica computer can successfully `rsh` to the Geomview computer without giving a password.

You can also explicitly set the `DisplayHost` option to the `Geomview` command to a string which is the desired hostname, for example:

         In[1] := << OOGL.m

         In[2] := Plot3D[Sin[x + Sin[y]], {x,-2,2},{y,-2,2}]

         Out[2] := -Graphics3D-

         In[3] := Geomview[%3, DisplayHost->"riemann"]

This displays the graphics `%3` on the remote host named `riemann`.

`Geomview` recognizes the string `"local"` as a value for `$DisplayHost`; it forces the graphics to be displayed on the local machine.

In addition to knowing the name of the machine you want to run Geomview on, `Geomview` needs to know the type of that machine (the setting of the CPU variable that corresponds to the machine; see Source Code Installation). By default, `Geomview` assumes that it is the same kind of computer as the one you are running Mathematica on. The `MachType` option lets you explicitly specify the type of the `DisplayHost` computer; it should be one of the strings `"sgi"` or `"next"` or `"x11"`.

You can use `SetOptions` to change the default `DisplayHost` and `MachType`. For example,

         In[4] := SetOptions[Geomview, DisplayHost->"riemann", MachType->"sgi"]

arranges for `Geomview` to run Geomview on an SGI workstation named `riemann`.