1st lecture slides

2023/2023-03-07_julia-dsse/slides/00-index.md

@@ -8,13 +8,11 @@
 </div>
 
 <div style="top: 1em; left: 60%; position: absolute;">
-    <img src="slides/img/r3-training-logo.png" height="200px">
     <img src="slides/img/julia.svg" height="200px">
-    <h1 style="margin-top:3ex; margin-bottom:3ex;">Julia for newcomers</h1>
+    <h1 style="margin-top:3ex; margin-bottom:3ex;">01: Absolute basics</h1>
     <h4>
         Miroslav Kratochvíl<br>
         Laurent Heirendt<br>
-        R3 Team - <a href="mailto:lcsb-r3@uni.lu">lcsb-r3@uni.lu</a><br>
         LCSB, DSSE<br>
     </h4>
 </div>

2023/2023-03-07_julia-dsse/slides/0a-overview.md

@@ -3,7 +3,9 @@
 - Everything is in the slides
 - The slides (current version) are available at `courses.lcsb.uni.lu`
 - Ask questions immediately
-- Offline questions best sent by e-mail (`miroslav.kratochvil@uni.lu`)
+- Offline questions best sent by e-mail
+  - `miroslav.kratochvil@uni.lu`
+  - `laurent.heirendt@uni.lu`
 
 
 
@@ -24,14 +26,14 @@
 
 # <i class="twa twa-ledger"></i> Homework
 
-- HW 0: trivial, touch the tooling
-  - Solution period: 7.3. — 14.3.
-- HW 1: basic programming
-  - Solution period: 7.3. — 21.3.
-- HW 2: making your code go fast
-  - Solution period: 14.3. — 28.3.
-- HW 3: managing types and complex things
-  - Solution period: 21.3. — exam
+- *HW 0*: trivial, touch the tooling
+  - Solution period: 7.3. — *14.3*.
+- *HW 1*: basic programming
+  - Solution period: 7.3. — *21.3*.
+- *HW 2*: making your code go fast
+  - Solution period: 14.3. — *28.3*.
+- *HW 3*: managing types and complex things
+  - Solution period: 21.3. — *exam*
 
 ## Guidelines
 
@@ -57,5 +59,7 @@
 # <i class="twa twa-woman-teacher"></i> Knowing the demographics is important!
 
 - Our background is almost entirely technical.
+  - We did several scientific computing packages for Julia
+  - MK was previously teaching a pretty wide spectrum of other programming languages
 - What do *you* currently use for programming?
 - What's *your* area of interest?

2023/2023-03-07_julia-dsse/slides/1a-intro.md

@@ -29,3 +29,16 @@
 # Why Julia?
 
 <center><img src="slides/img/whyjulia.png" width="80%"></center>
+
+
+
+# So what is high performance?
+
+- You can process more data with the same resources = You can generate more results
+- At some point, you can't get a better algorithm.
+
+High-performance comupting is:
+- getting speedup by optimizing the constant factor in the algorithm complexity
+  - speedup generated by removing various overhead
+- getting speedup by parallelizing parts of the algorithm
+  - speedup generated by adding more computers

2023/2023-03-07_julia-dsse/slides/1d-io.md

@@ -67,6 +67,8 @@ open("inputs.txt", "r") do io
 end
 ```
 
+Memory-consuming alternative: `readlines`
+
 
 
 # Extremely useful: string interpolation

2023/2023-03-07_julia-dsse/slides/1e-exercises.md

+
+# Exercise: write a median function
+
+Approaches (let's do at least 2)
+- sort and pick
+- quick-median (aka. lightweight sort&pick, as in quicksort)
+- approximation-improving-median
+  - this parallelizes well
+  - at which point is this faster than quick-median?
+  - did we lose any property?
+    - what about median strings?
+
+
+
+# Homework 0
+Make a package from the "trivial" median algorithm.
+
+- Use julia's `]generate`.
+- Have a look at how unit tests are done
+- Make sure this unittest works:
+
+```julia
+using MagicMedian
+
+@testset "median funcitonality test" begin
+	@test simplemedian([1,2,3,4]) >= 2
+	@test simplemedian([1,2,3,4]) <= 3
+	@test simplemedian([2,6,8]) == 6
+end
+```
+
+- Zip the package (or `.tar.gz` it or whatever) and upload it to Moodle
+
+How to run unit tests?
+- place unittest code into `test/runtests.jl` in the package file
+- run `]test MagicMedian`
+
+
+
+# Exercise: let's play a maze game
+
+- Read a maze from a file (let's have `0`s for a corridor and `1`s for a wall)
+- Draw it to console using `.` and `#`, add a border.
+- Make a function that annotates the whole maze based on how many (axis-aligned) steps a person (maze inhabitant) needs to take from some point
+  - let's use the slow <i class="twa twa-water-wave"></i>wave<i class="twa twa-water-wave"></i> algorithm
+- Use `UnicodePlots` to plot interesting stuff
+  - shortest path length distribution
+  - shortest-path-length heatmap of the maze
+  - "most blocking walls" (how much time to reach the father side of the wall could be gained by removing the wall?)
+
+
+
+# Exercise: Tricky questions about the maze
+
+What is the slowest part of the "wave" solution?
+
+How can we make it faster?
+
+
+
+# Homework 1
+
+Make a *faster* version of the maze distance computation.
+
+- any definiton of "faster solution" works; keep it terse
+- recommended way:
+  - Use `DataStructures.jl` or any other Julia package to get a priority queue working
+  - Implement some simple version of Dijkstra's algorithm
+- alternatively, try to optimize our naive array algorithm
+- measure your speedup with `@time` on mazes of at least `128*128` tiles
+- data for testing will be available (probably on Moodle)
+
+Submission:
+- wrap your code into a package `MagicMaze`
+- include a function `maze_distance_map(x::Int, y::Int)::Matrix{Int}`
+- write a unit test that demonstrates the result
+- pack the package and upload it to Moodle

2023/2023-03-07_julia-dsse/slides/2a-details.md

-
-<div class=leader>
-<i class="twa twa-mechanical-arm"></i>
-<i class="twa twa-battery"></i>
-<i class="twa twa-nut-and-bolt"></i>
-<i class="twa twa-mechanical-leg"></i>
-<br>
-Language in depth
-</div>

2023/2023-03-07_julia-dsse/slides/3a-sci.md

-
-<div class=leader>
-<i class="twa twa-volcano"></i>
-<i class="twa twa-mount-fuji"></i>
-<i class="twa twa-snow-capped-mountain"></i>
-<i class="twa twa-mountain"></i>
-<i class="twa twa-sunrise-over-mountains"></i>
-<br>
-Julia for scientific computing 
-</div>
-

2023/2023-03-07_julia-dsse/slides/4a-scipkgs.md

-
-
-<div class=leader>
-<i class="twa twa-horse-face"></i>
-<i class="twa twa-zebra"></i>
-<i class="twa twa-chicken"></i>
-<i class="twa twa-unicorn"></i>
-<br>
-Ecosystem
-</div>
-

2023/2023-03-07_julia-dsse/slides/5a-para.md

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-<div class=leader>
-<i class="twa twa-rocket"></i>
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-<br>
-Parallel Julia
-</div>

2023/2023-03-07_julia-dsse/slides/6a-types.md

-
-<div class=leader>
-<i class="twa twa-locomotive"></i>
-<i class="twa twa-helicopter"></i>
-<i class="twa twa-police-car"></i>
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-<br>
-Data and their types
-</div>

2023/2023-03-07_julia-dsse/slides/9-end.md

-
-<div class=leader>
-<i class="twa twa-basketball"></i><br>
-<i class="twa twa-wastebasket"></i><br>
-The End
-</div>
-
-What next?

2023/2023-03-07_julia-dsse/slides/list.json

@@ -5,10 +5,5 @@
     { "filename": "1b-bootstrap.md" },
     { "filename": "1c-language.md" },
     { "filename": "1d-io.md" },
-    { "filename": "2a-details.md" },
-    { "filename": "3a-sci.md" },
-    { "filename": "4a-scipkgs.md" },
-    { "filename": "5a-para.md" },
-    { "filename": "6a-types.md" },
-    { "filename": "9-end.md" }
+    { "filename": "1e-exercises.md" }
 ]