gspiceui software package provides Graphical user interface for gnucap and ngspice, you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install gspiceui
gspiceui is installed in your system.
Make ensure the gspiceui package were installed using the commands given below,
$ sudo dpkg-query -l | grep gspiceui *
You will get with gspiceui package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | Electronics |
| Package | gspiceui |
| Version | 1.1.00+dfsg-1build1 |
| Description | Graphical user interface for gnucap and ngspice |
| Sub Section | Electronics |