linked tutorials on main page and updated magclass tutorial

_config.yml

@@ -53,7 +53,7 @@ header_pages:
   # - _magpie24/call.md
   - _magpie24/registration.md
   - _magpie24/timetable.md
-  - about.md
+  - tutorials.md
 
 include:
   - _magpie24

_tutorials/t13_magclass.md

@@ -9,11 +9,34 @@ author: jpd
 level: 3
 requirements:
   - Basic knowledge of R programming language
-  - Install magclass package
+  - R installation
 lessonsContent:
   - Introduction to the magclass data class
   - magclass object functionality
   - data manipulation with magclass objects
+exercises:
+  - task: "Take the \"animal\" example data set from the magclass package and compute how many rabbits there are reported in Luxembourg (LUX) in may of each available year."
+    solution: "1. `library(magclass)` \n
+               2. `a <- maxample(\"animal\")` \n
+               3. `dimSums(a[\"LUX\",\"may\",\"rabbit\"], dim = 3)` \n
+               4. Result is: 16 in 2000, 34 in 2001 and 100 in 2002"
+  - task: "Write down three options to select the values for birds in Luxembourg (LUX) from the \"animal\" example data set."
+    solution: "1. `library(magclass)` \n
+               1. `a <- maxample(\"animal\")` \n
+               2. `a[\"LUX\",,\"bird\"]` \n
+               3. `mselect(a, country = \"LUX\", species = \"bird\")` \n
+               4. `a[list(country = \"LUX\"),,list(species = \"bird\")]`\n
+               5. Bonus: `a[\"LUX\", dim = 1][\"bird\", dim = 3]`"
+  - task: "Set all values for red birds in the animal data set to 0 and all values greater than 10 to 10."
+    solution: "1. `library(magclass)` \n
+               1. `a <- maxample(\"animal\")` \n
+               2. `a[,,\"bird\"][,,\"red\"] <- 0` \n
+               3. `a[a > 10] <- 10`"
+  - task: "Rename all dogs in the animal data set to cats and remove the \"type\" subdimension."
+    solution: "1. `library(magclass)` \n
+               1. `a <- maxample(\"animal\")` \n
+               2. `getItems(a, dim = \"species\")[3] <- \"cat\"` \n
+               3. `getItems(a, dim = \"type\") <- NULL`"
 published: true
 ---
 
@@ -22,13 +45,16 @@ published: true
 The `magclass` package is the data class most R functionality of MAgPIE is built on. Installing it is easy:
 
 ```r
-options(repos = c(CRAN = "https://cran.rstudio.com/", pik = "https://rse.pik-potsdam.de/r/packages"))
+options(repos = c(CRAN = "https://cran.rstudio.com/",
+                  pik = "https://rse.pik-potsdam.de/r/packages"))
 install.packages("madrat")
 library(madrat)
 ```
 
 Setting the `repos` option in the first line is optional and adds the PIK-hosted package repository as second repository after the official CRAN repository. Doing so will make sure that you receive the most up-to-date version of `magclass`, without this line the package version currently hosted on CRAN will be installed, which is updated less regularly. 
 
+## Vignettes
+
 The package comes with some vignettes (tutorials) which introduce you to the world of `magclass` and which also serve as basis for this tutorial. To list all tutorials run:
 
 ```r
@@ -43,7 +69,7 @@ vignette("magclass")
 
 All vignettes are also hosted on the internet:
 
-* [magclass main tutorial](https://pik-piam.r-universe.dev/magclass/doc/magclass.html)
-* [magclass concept](https://pik-piam.r-universe.dev/magclass/doc/magclass-concept.html)
-* [magclass object expansion](https://pik-piam.r-universe.dev/magclass/doc/magclass-expansion.html)
-* [magclass 6](https://pik-piam.r-universe.dev/magclass/doc/magclass6.html)
+* [**magclass concept**](https://pik-piam.r-universe.dev/magclass/doc/magclass-concept.html): Explaining the general concept behing magclass objects in comparison to arrays and data frames
+* [**magclass main tutorial**](https://pik-piam.r-universe.dev/magclass/doc/magclass.html): Central tutorial explaining the basics how to use magclass
+* [**magclass 6**](https://pik-piam.r-universe.dev/magclass/doc/magclass6.html): Tutorial about some important changes which came with the complete rewrite of the package in version 6. 
+* [**magclass object expansion**](https://pik-piam.r-universe.dev/magclass/doc/magclass-expansion.html): more specific tutorial going into the details of object expansion and set matching.