Add test for DWI optimisation

test/runtests.jl

@@ -2,6 +2,7 @@ using MRIBuilder
 using Test
 
 @testset "MRIBuilder.jl" begin
+    include("test_sequences.jl")
     include("test_IO.jl")
     include("test_plot.jl")
 end

test/test_sequences.jl

+@testset "test_sequences.jl" begin
+    
+    @testset "DW-SE" begin
+        @testset "Instant pulse & readout" begin
+            @testset "Minimise TE" begin
+                seq = DiffusionSpinEcho(TE=:min, bval=1.)
+                @test length(seq) == 9
+                grad_duration = TE(seq) / 2
+                @test all(isapprox.(duration.(seq), [0., 0., grad_duration, 0., 0., 0., grad_duration, 0., 0.], atol=1e-6))
+                @test length([iter_instant_pulses(seq)...]) == 2
+                @test length([iter_instant_gradients(seq)...]) == 0.
+                @test bval(seq) ≈ 1.
+                @test 40. < TE(seq) < 50.
+                @test TR(seq) ≈ TE(seq)
+            end
+            @testset "Maximise b-value" begin
+                seq = DiffusionSpinEcho(TE=80., bval=:max)
+                @test length(seq) == 9
+                @test all(isapprox.(duration.(seq), [0., 0., 40., 0., 0., 0., 40., 0., 0.], atol=1e-4, rtol=1e-4))
+                @test length([iter_instant_pulses(seq)...]) == 2
+                @test length([iter_instant_gradients(seq)...]) == 0.
+                @test TE(seq) ≈ 80.
+                @test TR(seq) ≈ 80.
+                @test 4.8 < bval(seq) < 4.9
+
+                # can also maximise q-value
+                seq2 = DiffusionSpinEcho(TE=80., qval=:max)
+                @test all(isapprox.(duration.(seq), duration.(seq2), atol=1e-4, rtol=1e-4))
+                @test TE(seq) ≈ TE(seq2) atol=1e-4 rtol=1e-4
+                @test bval(seq) ≈ bval(seq2) atol=1e-4 rtol=1e-4
+            end
+            @testset "Set diffusion time Δ" begin
+                seq = DiffusionSpinEcho(TE=80., Δ=70., qval=:max)
+                @test all(isapprox.(duration.(seq), [0., 0., 10., 30., 0., 30., 10., 0., 0.], atol=1e-4, rtol=1e-4))
+                @test Δ(seq) ≈ 70.
+                @test TE(seq) ≈ 80.
+                @test TR(seq) ≈ 80.
+                @test 0.72 < bval(seq) < 0.73
+            end
+            @testset "Set gradient duration" begin
+                seq = DiffusionSpinEcho(TE=80., gradient=(duration=10., ), bval=:max)
+                @test all(isapprox.(duration.(seq), [0., 0., 10., 30., 0., 30., 10., 0., 0.], atol=1e-4, rtol=1e-4))
+                @test Δ(seq) ≈ 70.
+                @test TE(seq) ≈ 80.
+                @test TR(seq) ≈ 80.
+                @test 0.72 < bval(seq) < 0.73
+            end
+        end
+
+    end
+end
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