change meaning of rev

Author: lkdvos

src/implementations/orthnull.jl

@@ -207,7 +207,7 @@ function null_truncation_strategy(; atol=nothing, rtol=nothing, maxnullity=nothi
     end
     atol = @something atol 0
     rtol = @something rtol 0
-    trunc = trunctol(; atol, rtol, rev=false)
+    trunc = trunctol(; atol, rtol, rev=true)
     return !isnothing(maxnullity) ? trunc & truncrank(maxnullity; rev=false) : trunc
 end
 

src/implementations/truncation.jl

@@ -52,18 +52,18 @@ end
 
 function findtruncated(values::AbstractVector, strategy::TruncationByValue)
     atol = max(strategy.atol, strategy.rtol * norm(values, strategy.p))
-    filter = (strategy.rev ? ≥(atol) : ≤(atol)) ∘ strategy.by
+    filter = (strategy.rev ? ≤(atol) : ≥(atol)) ∘ strategy.by
     return findall(filter, values)
 end
 function findtruncated_sorted(values::AbstractVector, strategy::TruncationByValue)
     atol = max(strategy.atol, strategy.rtol * norm(values, strategy.p))
     @assert strategy.by === abs || strategy.by === real "sorting strategy incompatible with implementation"
     if strategy.rev
-        i = searchsortedlast(values, atol; by=strategy.by, rev=true)
-        return 1:i
-    else
         i = searchsortedfirst(values, atol; by=strategy.by, rev=true)
         return i:length(values)
+    else
+        i = searchsortedlast(values, atol; by=strategy.by, rev=true)
+        return 1:i
     end
 end
 

src/interface/truncation.jl

@@ -80,10 +80,10 @@ Truncation strategy to keep the values for which `filter` returns true.
 truncfilter(f) = TruncationByFilter(f)
 
 """
-    TruncationByValue(atol::Real, rtol::Real, p::Real, by, rev::Bool=true)
+    TruncationByValue(atol::Real, rtol::Real, p::Real, by, rev::Bool=false)
 
-Truncation strategy to keep the values that satisfy `by(val) < max(atol, rtol * norm(values, p)`
-if `rev = true`, or discard them when `rev = false`.
+Truncation strategy to keep the values that satisfy `by(val) > max(atol, rtol * norm(values, p)`
+if `rev = false`, or discard them when `rev = true`.
 See also [`trunctol`](@ref)
 """
 struct TruncationByValue{T<:Real,P<:Real,F} <: TruncationStrategy
@@ -98,12 +98,12 @@ function TruncationByValue(atol::Real, rtol::Real, p::Real=2, by=abs, rev::Bool=
 end
 
 """
-    trunctol(; atol::Real=0, rtol::Real=0, p::Real=2, by=abs, )
+    trunctol(; atol::Real=0, rtol::Real=0, p::Real=2, by=abs, rev::Bool=false)
 
-Truncation strategy to keep the values that satisfy `by(val) < max(atol, rtol * norm(values, p)`
-if `rev = true`, or discard them when `rev = false`.
+Truncation strategy to keep the values that satisfy `by(val) > max(atol, rtol * norm(values, p)`
+if `rev = false`, or discard them when `rev = true`.
 """
-function trunctol(; atol::Real=0, rtol::Real=0, p::Real=2, by=abs, rev::Bool=true)
+function trunctol(; atol::Real=0, rtol::Real=0, p::Real=2, by=abs, rev::Bool=false)
     return TruncationByValue(atol, rtol, p, by, rev)
 end
 

test/algorithms.jl

@@ -50,7 +50,7 @@ end
                                  notrunc())
     end
 
-    alg = TruncatedAlgorithm(LAPACK_Simple(), trunctol(; atol=0.1, rev=false))
+    alg = TruncatedAlgorithm(LAPACK_Simple(), trunctol(; atol=0.1, rev=true))
     for f in (eig_trunc!, eigh_trunc!, svd_trunc!)
         @test @constinferred(select_algorithm(eig_trunc!, A, alg)) === alg
         @test_throws ArgumentError select_algorithm(eig_trunc!, A, alg; trunc=(; maxrank=2))

test/orthnull.jl

@@ -125,7 +125,7 @@ end
 
         rtol = eps(real(T))
         for (trunc_orth, trunc_null) in (((; rtol=rtol), (; rtol=rtol)),
-                                         (trunctol(; rtol), trunctol(; rtol, rev=false)))
+                                         (trunctol(; rtol), trunctol(; rtol, rev=true)))
             V2, C2 = @constinferred left_orth!(copy!(Ac, A), (V, C); trunc=trunc_orth)
             N2 = @constinferred left_null!(copy!(Ac, A), N; trunc=trunc_null)
             @test V2 !== V

test/truncate.jl

@@ -18,7 +18,7 @@ using MatrixAlgebraKit: NoTruncation, TruncationIntersection, TruncationByOrder,
     @test trunc == trunctol(; atol, rtol)
     @test trunc.atol == atol
     @test trunc.rtol == rtol
-    @test trunc.rev
+    @test !trunc.rev
 
     trunc = @constinferred TruncationStrategy(; maxrank)
     @test trunc isa TruncationByOrder
@@ -41,7 +41,7 @@ using MatrixAlgebraKit: NoTruncation, TruncationIntersection, TruncationByOrder,
     strategy = trunctol(; atol=0.4)
     @test @constinferred(findtruncated(values, strategy)) == 1:3
     @test @constinferred(findtruncated_sorted(values, strategy)) === 1:3
-    strategy = trunctol(; atol=0.4, rev=false)
+    strategy = trunctol(; atol=0.4, rev=true)
     @test @constinferred(findtruncated(values, strategy)) == 4:5
     @test @constinferred(findtruncated_sorted(values, strategy)) === 4:5
 
@@ -53,10 +53,10 @@ using MatrixAlgebraKit: NoTruncation, TruncationIntersection, TruncationByOrder,
     @test @constinferred(findtruncated(values, strategy)) == [2, 3, 4, 5]
 
     for strategy in
-        (trunctol(; atol=0.4, rev=false), trunctol(; atol=0.2, by=identity, rev=false))
+        (trunctol(; atol=0.4, rev=true), trunctol(; atol=0.2, by=identity, rev=true))
         @test @constinferred(findtruncated(values, strategy)) == [1, 4]
     end
-    strategy = trunctol(; atol=0.2, rev=false)
+    strategy = trunctol(; atol=0.2, rev=true)
     @test @constinferred(findtruncated(values, strategy)) == [1]
 
     strategy = truncfilter(x -> 0.1 < x < 1)