Change maxrank to maxnullity in null methods

Author: mtfishman

src/implementations/orthnull.jl

@@ -156,14 +156,14 @@ end
 
 # Implementation of null functions
 # --------------------------------
-function null_truncation_strategy(; atol=nothing, rtol=nothing, maxrank=nothing)
-    if isnothing(maxrank) && isnothing(atol) && isnothing(rtol)
+function null_truncation_strategy(; atol=nothing, rtol=nothing, maxnullity=nothing)
+    if isnothing(maxnullity) && isnothing(atol) && isnothing(rtol)
         return NoTruncation()
     end
     atol = @something atol 0
     rtol = @something rtol 0
     trunc = TruncationKeepBelow(atol, rtol)
-    return !isnothing(maxrank) ? trunc & truncrank(maxrank; rev=false) : trunc
+    return !isnothing(maxnullity) ? trunc & truncrank(maxnullity; rev=false) : trunc
 end
 
 function left_null!(A::AbstractMatrix, N; trunc=nothing,

src/interface/orthnull.jl

@@ -149,7 +149,7 @@ that should be used to factor `A`, whereas `trunc` can be used to control the
 the rank of `A` via its singular values.
 
 `trunc` can either be a truncation strategy object or a NamedTuple with fields
-`atol`, `rtol`, and `maxrank`.
+`atol`, `rtol`, and `maxnullity`.
 
 This is a high-level wrapper and will use one of the decompositions `qr!` or `svd!`
 to compute the orthogonal basis `N`, as controlled by the keyword arguments.
@@ -199,7 +199,7 @@ that should be used to factor `A`, whereas `trunc` can be used to control the
 the rank of `A` via its singular values.
 
 `trunc` can either be a truncation strategy object or a NamedTuple with fields
-`atol`, `rtol`, and `maxrank`.
+`atol`, `rtol`, and `maxnullity`.
 
 This is a high-level wrapper and will use one of the decompositions `lq!` or `svd!`
 to compute the orthogonal basis `Nᴴ`, as controlled by the keyword arguments.

test/orthnull.jl

@@ -23,6 +23,19 @@ using MatrixAlgebraKit: TruncationKeepAbove, TruncationKeepBelow
         @test N' * N ≈ I
         @test V * V' + N * N' ≈ I
 
+        if m > n
+            nullity = 5
+            V, C = @constinferred left_orth(A)
+            N = @constinferred left_null(A; trunc=(; maxnullity=nullity))
+            @test V isa Matrix{T} && size(V) == (m, minmn)
+            @test C isa Matrix{T} && size(C) == (minmn, n)
+            @test N isa Matrix{T} && size(N) == (m, nullity)
+            @test V * C ≈ A
+            @test V' * V ≈ I
+            @test LinearAlgebra.norm(A' * N) ≈ 0 atol = MatrixAlgebraKit.defaulttol(T)
+            @test N' * N ≈ I
+        end
+
         for alg_qr in ((; positive=true), (; positive=false), LAPACK_HouseholderQR())
             V, C = @constinferred left_orth(A; alg_qr)
             N = @constinferred left_null(A; alg_qr)