## AMPL Session from Lecture 25, 11/12/2024

# We illustrate the use of 'read' command to read in data saved as
# text files on the Killer Drugs LP example.

# We have the Compos matrix parameter saved in a text file titled
# Compos.txt, available in the present working directory along with
# the model and data files. Just to ensure the data is read in
# correctly, we change some of the values of Compos as listed in this
# file:
#	0.34 0.61 0.53
#	0.07 0.11 0.09
#	0.14 0.09 0.72
#	0.04 0.05 0.11


ampl: reset; model KillerDrugsDoozey.mod.txt; data KillerDrugsDoozey.dat.txt;
ampl: display Compos;
Compos :=
1 A   0.04
1 B   0.08
1 C   0.03
2 A   0.07
2 B   0.11
2 C   0.09
3 A   0.14
3 B   0.09
3 C   0.12
4 A   0.04
4 B   0.05
4 C   0.11
;

# Note that these are the values originally listed in the data file

# We now read in the data from Compos.txt:

ampl: read {i in 1..nChem, j in Ingreds} Compos[i,j] < Compos.txt;
ampl: close Compos.txt;

# It's a good idea to "close" the file after reading from it is
# finished---especially if you're going to read from a different file
# afterward.

ampl: display Compos;
Compos :=
1 A   0.34
1 B   0.61
1 C   0.53
2 A   0.07
2 B   0.11
2 C   0.09
3 A   0.14
3 B   0.09
3 C   0.72
4 A   0.04
4 B   0.05
4 C   0.11
;

ampl: