Summary and Setup

Welcome to Hands-on QGIS on HPC Clusters

Welcome to the Hands-on QGIS Workshop, where you’ll learn to navigate and utilize QGIS, a powerful open-source Geographic Information System (GIS) on HPC Clusters.

What You’ll Learn:

  1. Get Started with QGIS. We’ll cover the basics of opening QGIS on HPC clusters, loading, viewing, processing and exporting spatial data.
  • Introduction
  • Open QGIS on Clusters
  • View Spatial Data
  • Process Spatial Data
  1. Project: Exploring landscape around Purdue. Through a hands-on project, you’ll learn to apply raster analysis techniques to explore the landscape around Purdue University. We will also cover installing plugins such as QuickMapServices and WhiteboxTools. Specifically, you’ll work with:
  • Slope
  • Hill shade
  • Stream and watershed
  • Raster to Vector
  1. Coding with QGIS: Python Console and more. Take your analysis to the next level by learning how to write scripts using the QGIS Python Console and more. You’ll learn how to automate geospatial tasks, such as replicating the same tasks you performed in the “Exploring Landscape around Purdue” project, but this time using code and submiting jobs to HPC clusters. By automating these tasks, you’ll be able to streamline your workflow and increase efficiency.

Instructor

Xiao Liu: Xiao is a Senior Computational Scientist at Purdue University’s Rosen Center for Advanced Computing. She has two Masters in Geosciences and a Master in Computer Sciences and Engineering. Her knowledge encompassed GIS, machine learning, and hydrologic modeling.

Schedule

Time Session
10:00 AM Arrival & Setup
10:30 AM Introduction & Open QGIS on Clusters
11:00 AM View and Process Spatial Data
12:00 PM Lunch Break
1:00 PM Project: Exploring landscape around Purdue
2:30 PM Break
3:00 PM Coding with QGIS: Python Console and more
4:30 PM Wrap-Up & Discussion

Software Setup

  1. SSH key setup for different systems is detailed in the expandable sections below.

Open a terminal locally on your laptop and run:

SH 

ssh-keygen -b 4096 -t rsa

this generates the ssh key

OUTPUT 

Generating public/private rsa key pair.
Enter file in which to save the key (/Users/your_laptop_account/.ssh/id_rsa):

Now you hit “enter”,

OUTPUT 

Enter passphrase (empty for no passphrase):
Enter same passphrase again:

Now you hit “enter” again twice to confirm your input passphrase (no passphrase in this case).

OUTPUT 

Your identification has been saved in /Users/your_laptop_account/.ssh/id_rsa
Your public key has been saved in /Users/your_laptop_account/.ssh/id_rsa.pub
The key fingerprint is:
SHA256:0vHGCotXkhEg4IKmpJvM92ivPFFyB81l2XgIFTkdsZ8 your_laptop_account@pal-nat187-15-102.itap.purdue.edu
The key's randomart image is:
+---[RSA 4096]----+
|... ..+.+=Ooo    |
|o  . . +.* +.    |
|o+    o . o.     |
|*  . o = +  . .  |
|o   + * S +  E   |
|oo . . * o       |
|oo .o o .        |
|  ooo.           |
|  .++o           |
+----[SHA256]-----+

Now you run:

SH 

type .ssh\id_rsa.pub | ssh trainXX@negishi.rcac.purdue.edu "mkdir -p ~/.ssh; cat >> ~/.ssh/authorized_keys"

SH 

cat .ssh/id_rsa.pub | ssh trainXX@negishi.rcac.purdue.edu "mkdir -p ~/.ssh; cat >> ~/.ssh/authorized_keys"

Then you input the password written in the whiteboard

this copies the ssh key to trainXX on Negishi

and then run:

SH 

ssh trainXX@negishi.rcac.purdue.edu

this connects negishi with ssh

You should be able to land on Negishi without password, which means you will see:

OUTPUT 

TrainXX@login0X.negishi:[~] $

  1. Download the ThinLinc Client and install it to your Laptop.

  2. Open ThinLinc Client, then go to Options -> Security, and select “Public key” in the “Anthentication method” as here:

    Screenshot 2025-02-21 at 2 27 31 PM

  3. Input Server, Username(replace XX with your train number) and Key(correct it with your path of key) like here:

    Screenshot 2025-02-21 at 2 27 11 PM

  4. Hit “Connect”.

Data Sets

Copy data to your scratch directory:

SH 

rsync -avP /depot/workshop/data/qgis/data $RCAC_SCRATCH