Add AFIRO.sif in QM tutorial (#108)

Author: tmigot

tutorials/introduction-to-quadraticmodels/assets/AFIRO.SIF

@@ -0,0 +1,93 @@
+***************************
+* SET UP THE INITIAL DATA *
+***************************
+NAME          AFIRO                                                             
+*   Problem:
+*   ********
+*   An LP, contributed by Michael Saunders.
+*   Source:
+*   The NETLIB collection of test problems.
+*   SIF input: (already in MPS format)
+*   classification LLR2-AN-32-27
+ROWS
+ E  R09     
+ E  R10     
+ L  X05     
+ L  X21     
+ E  R12     
+ E  R13     
+ L  X17     
+ L  X18     
+ L  X19     
+ L  X20     
+ E  R19     
+ E  R20     
+ L  X27     
+ L  X44     
+ E  R22     
+ E  R23     
+ L  X40     
+ L  X41     
+ L  X42     
+ L  X43     
+ L  X45     
+ L  X46     
+ L  X47     
+ L  X48     
+ L  X49     
+ L  X50     
+ L  X51     
+ N  COST    
+COLUMNS
+    X01       X48               .301   R09                -1.   
+    X01       R10              -1.06   X05                 1.   
+    X02       X21                -1.   R09                 1.   
+    X02       COST               -.4   
+    X03       X46                -1.   R09                 1.   
+    X04       X50                 1.   R10                 1.   
+    X06       X49               .301   R12                -1.   
+    X06       R13              -1.06   X17                 1.   
+    X07       X49               .313   R12                -1.   
+    X07       R13              -1.06   X18                 1.   
+    X08       X49               .313   R12                -1.   
+    X08       R13               -.96   X19                 1.   
+    X09       X49               .326   R12                -1.   
+    X09       R13               -.86   X20                 1.   
+    X10       X45              2.364   X17                -1.   
+    X11       X45              2.386   X18                -1.   
+    X12       X45              2.408   X19                -1.   
+    X13       X45              2.429   X20                -1.   
+    X14       X21                1.4   R12                 1.   
+    X14       COST              -.32   
+    X15       X47                -1.   R12                 1.   
+    X16       X51                 1.   R13                 1.   
+    X22       X46               .109   R19                -1.   
+    X22       R20               -.43   X27                 1.   
+    X23       X44                -1.   R19                 1.   
+    X23       COST               -.6   
+    X24       X48                -1.   R19                 1.   
+    X25       X45                -1.   R19                 1.   
+    X26       X50                 1.   R20                 1.   
+    X28       X47               .109   R22               -.43   
+    X28       R23                 1.   X40                 1.   
+    X29       X47               .108   R22               -.43   
+    X29       R23                 1.   X41                 1.   
+    X30       X47               .108   R22               -.39   
+    X30       R23                 1.   X42                 1.   
+    X31       X47               .107   R22               -.37   
+    X31       R23                 1.   X43                 1.   
+    X32       X45              2.191   X40                -1.   
+    X33       X45              2.219   X41                -1.   
+    X34       X45              2.249   X42                -1.   
+    X35       X45              2.279   X43                -1.   
+    X36       X44                1.4   R23                -1.   
+    X36       COST              -.48   
+    X37       X49                -1.   R23                 1.   
+    X38       X51                 1.   R22                 1.   
+    X39       R23                 1.   COST               10.   
+RHS
+    B         X50               310.   X51               300.   
+    B         X05                80.   X17                80.   
+    B         X27               500.   R23                44.   
+    B         X40               500.   
+ENDATA

tutorials/introduction-to-quadraticmodels/index.jmd

@@ -115,10 +115,11 @@ qmSlack = SlackModel(qmCOO)
 ## Read MPS/SIF files
 
 You can read directly MPS or SIF files using [`QPSReader.jl`](https://github.com/JuliaSmoothOptimizers/QPSReader.jl)
+in order to read convex quadratic problems in MPS or SIF formats.
 
 ```julia
 using QPSReader
-qps = readqps("AFIRO.SIF")
+qps = readqps("assets/AFIRO.SIF")
 qmCOO4 = QuadraticModel(qps)
 ```