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[FileFormats.LP] fix reading models with default bounds #2121

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Merged
merged 2 commits into from
Mar 16, 2023
Merged

[FileFormats.LP] fix reading models with default bounds #2121

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af2188e
[FileFormats.LP] fix reading models with default bounds
odow Mar 16, 2023
75fd08c
Fix bound tests
odow Mar 16, 2023
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6 changes: 0 additions & 6 deletions src/FileFormats/LP/LP.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -778,9 +778,6 @@ function _parse_section(
if _is_less_than(tokens[2])
# name <= bound
ub = rhs
# LP files have default lower bounds of 0, unless the upper
# bound is less than 0.
lb = ub > 0.0 ? 0.0 : -Inf
elseif _is_greater_than(tokens[2])
# name >= bound
lb = rhs
Expand All @@ -800,9 +797,6 @@ function _parse_section(
elseif _is_greater_than(tokens[2])
# bound >= name
ub = lhs
# LP files have default lower bounds of 0, unless the upper
# bound is less than 0.
lb = ub > 0.0 ? 0.0 : -Inf
elseif _is_equal_to(tokens[2])
lb = ub = lhs
else
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84 changes: 79 additions & 5 deletions test/FileFormats/LP/LP.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -469,7 +469,8 @@ function test_read_model1_tricky()
@test occursin("Var4 >= 5.5", file)
@test occursin("V3 >= -3", file)
@test occursin("V5 = 1", file)
@test occursin("0 <= V2 <= 3", file)
@test occursin("V2 <= 3", file)
@test occursin("V2 >= 0", file)
@test occursin("0 <= V7 <= 1", file)
@test occursin("0 <= V8 <= 1", file)
@test occursin("V6 free", file)
Expand Down Expand Up @@ -717,15 +718,15 @@ end
function test_wrong_way_bounds()
for (case, result) in [
"x >= 2" => "x >= 2",
"x <= 2" => "0 <= x <= 2",
"x <= 2" => "x <= 2\nx >= 0",
"x == 2" => "x = 2",
"x > 2" => "x >= 2",
"x < 2" => "0 <= x <= 2",
"x < 2" => "x <= 2\nx >= 0",
"x = 2" => "x = 2",
"2 >= x" => "0 <= x <= 2",
"2 >= x" => "x <= 2\nx >= 0",
"2 <= x" => "x >= 2",
"2 == x" => "x = 2",
"2 > x" => "0 <= x <= 2",
"2 > x" => "x <= 2\nx >= 0",
"2 < x" => "x >= 2",
"2 = x" => "x = 2",
]
Expand Down Expand Up @@ -758,6 +759,79 @@ function test_variable_coefficient_variable()
return
end

function _test_round_trip(bound, needle)
model = MOI.FileFormats.LP.Model()
io = IOBuffer()
write(io, "Minimize\nobj: x\nBounds\n$bound\nEnd")
seekstart(io)
read!(io, model)
seekstart(io)
write(io, model)
seekstart(io)
file = read(io, String)
@test occursin(needle, file)
return
end

function test_reading_bounds()
# Test lower bound
_test_round_trip("x >= 1", "Bounds\nx >= 1\nEnd")
_test_round_trip("x >= 0", "Bounds\nx >= 0\nEnd")
_test_round_trip("x >= -1", "Bounds\nx >= -1\nEnd")
_test_round_trip("x > 1", "Bounds\nx >= 1\nEnd")
_test_round_trip("x > 0", "Bounds\nx >= 0\nEnd")
_test_round_trip("x > -1", "Bounds\nx >= -1\nEnd")
# Test reversed lower bound
_test_round_trip("1 <= x", "Bounds\nx >= 1\nEnd")
_test_round_trip("0 <= x", "Bounds\nx >= 0\nEnd")
_test_round_trip("-1 <= x", "Bounds\nx >= -1\nEnd")
_test_round_trip("1 < x", "Bounds\nx >= 1\nEnd")
_test_round_trip("0 < x", "Bounds\nx >= 0\nEnd")
_test_round_trip("-1 < x", "Bounds\nx >= -1\nEnd")
# Test upper bound
_test_round_trip("x <= 1", "Bounds\nx <= 1\nx >= 0\nEnd")
_test_round_trip("x <= 0", "Bounds\nx <= 0\nx >= 0\nEnd")
_test_round_trip("x <= -1", "Bounds\nx <= -1\nEnd")
_test_round_trip("x < 1", "Bounds\nx <= 1\nx >= 0\nEnd")
_test_round_trip("x < 0", "Bounds\nx <= 0\nx >= 0\nEnd")
_test_round_trip("x < -1", "Bounds\nx <= -1\nEnd")
# Test reversed upper bound
_test_round_trip("1 >= x", "Bounds\nx <= 1\nx >= 0\nEnd")
_test_round_trip("0 >= x", "Bounds\nx <= 0\nx >= 0\nEnd")
_test_round_trip("-1 >= x", "Bounds\nx <= -1\nEnd")
_test_round_trip("1 > x", "Bounds\nx <= 1\nx >= 0\nEnd")
_test_round_trip("0 > x", "Bounds\nx <= 0\nx >= 0\nEnd")
_test_round_trip("-1 > x", "Bounds\nx <= -1\nEnd")
# Test equality
_test_round_trip("x == 1", "Bounds\nx = 1\nEnd")
_test_round_trip("x == 0", "Bounds\nx = 0\nEnd")
_test_round_trip("x == -1", "Bounds\nx = -1\nEnd")
_test_round_trip("1 = x", "Bounds\nx = 1\nEnd")
_test_round_trip("0 = x", "Bounds\nx = 0\nEnd")
_test_round_trip("-1 = x", "Bounds\nx = -1\nEnd")
# Test interval
_test_round_trip("0 <= x <= 1", "Bounds\n0 <= x <= 1\nEnd")
_test_round_trip("-1 <= x <= 1", "Bounds\n-1 <= x <= 1\nEnd")
_test_round_trip("-2 <= x <= -1", "Bounds\n-2 <= x <= -1\nEnd")
# Test reversed interval
_test_round_trip("1 >= x >= 0", "Bounds\n0 <= x <= 1\nEnd")
_test_round_trip("1 >= x >= -1", "Bounds\n-1 <= x <= 1\nEnd")
_test_round_trip("-1 >= x >= -2", "Bounds\n-2 <= x <= -1\nEnd")
# Test double-sided equality
_test_round_trip("1 <= x <= 1", "Bounds\nx = 1\nEnd")
_test_round_trip("0 <= x <= 0", "Bounds\nx = 0\nEnd")
_test_round_trip("-2 <= x <= -2", "Bounds\nx = -2\nEnd")
# Test upper then lower
_test_round_trip("x <= 1\nx >= 0", "Bounds\nx <= 1\nx >= 0\nEnd")
_test_round_trip("x <= 2\nx >= 1", "Bounds\nx <= 2\nx >= 1\nEnd")
_test_round_trip("x <= 2\nx >= -1", "Bounds\nx <= 2\nx >= -1\nEnd")
# Test lower then upper
_test_round_trip("x >= 0\nx <= 1", "Bounds\nx <= 1\nx >= 0\nEnd")
_test_round_trip("x >= 1\nx <= 2", "Bounds\nx <= 2\nx >= 1\nEnd")
_test_round_trip("x >= -1\nx <= 2", "Bounds\nx <= 2\nx >= -1\nEnd")
return
end

function runtests()
for name in names(@__MODULE__, all = true)
if startswith("$(name)", "test_")
Expand Down