diff --git a/src/iradon.jl b/src/iradon.jl
index 4c3167b..94216d8 100644
--- a/src/iradon.jl
+++ b/src/iradon.jl
@@ -1,5 +1,7 @@
 export iradon
 
+iradon(sinogram::AbstractArray{T, 3}, angles::AbstractArray{T2, 1}; backend=CPU()) where {T, T2} =
+    iradon(sinogram, T.(angles); backend)
 
 function filtered_backprojection(sinogram::AbstractArray{T, 3}, θs, μ=nothing; backend=CPU()) where T
     filter = similar(sinogram, (size(sinogram, 1),))
diff --git a/src/radon.jl b/src/radon.jl
index c751095..bf691d9 100644
--- a/src/radon.jl
+++ b/src/radon.jl
@@ -1,5 +1,9 @@
 export radon
 
+radon(img::AbstractArray{T, 3}, angles::AbstractArray{T2, 1}; backend=CPU()) where {T, T2} =
+    radon(img, T.(angles); backend)
+
+
 """
     radon(I, θs; backend=CPU())
 
diff --git a/test/notebook.jl b/test/notebook.jl
index ee6236b..c53e513 100644
--- a/test/notebook.jl
+++ b/test/notebook.jl
@@ -1,5 +1,5 @@
 ### A Pluto.jl notebook ###
-# v0.19.26
+# v0.19.32
 
 using Markdown
 using InteractiveUtils
@@ -19,24 +19,24 @@ using RadonKA, ImageShow, IndexFunArrays, PlutoUI, CUDA
 
 # ╔═╡ 071b6c72-86ec-461a-ad7d-adf0fc696399
 begin
-	sinogram = zeros(Float32, (10, 2, 1))
+	sinogram = zeros(Float32, (9, 2, 1))
 	sinogram[5, :, 1] .= 1
 end
 
 # ╔═╡ 575487cf-faa2-41eb-9062-f030741be67b
-
+simshow(sinogram[:, :, 1])
 
 # ╔═╡ 7fcb40e4-4530-4ce1-a267-84b46309ab2a
-@show iradon(sinogram, [0], 1)
+@show iradon(sinogram, [0f0, π*1f0])
 
 # ╔═╡ 49629e15-c5f4-42ff-b196-24e13124f8f3
-@show I_r = iradon(sinogram, [2pi - pi/4], 1)
+@show I_r = iradon(sinogram, Float32[2pi - pi/4])
 
 # ╔═╡ be118fec-3051-47a4-bf15-ac9d8d8c8e2e
-sum(iradon(sinogram, [2pi - pi/4], 1))
+sum(iradon(sinogram, Float32[2pi - pi/4]))
 
 # ╔═╡ 80970ba6-a09f-46db-8b15-fa7226cdc400
-sum(iradon(sinogram, [0], 1))
+sum(iradon(sinogram, Float32[0]))
 
 # ╔═╡ c969f6d0-cfcc-4846-b970-9f6b734ac7cd
 simshow(I_r[:, :, 1])
@@ -71,21 +71,21 @@ simshow(I_2[:,:,1])
 
 # ╔═╡ 2435a78b-5142-483e-afaf-6091b78724a5
 begin
-	sinogram_big = zeros(Float32, (30, 2, 1))
+	sinogram_big = zeros(Float32, (29, 2, 1))
 	sinogram_big[20, :, 1] .= 1
 end
 
 # ╔═╡ 8d9b6ea3-bbc0-48c1-a824-9749d6b8df0f
-sum(iradon(sinogram_big, [0], 1)[:, :, 1])
+sum(iradon(sinogram_big, [0f0])[:, :, 1])
 
 # ╔═╡ 73a756d9-9984-4452-b90a-9cced7959813
-sum(iradon(sinogram_big, [pi/4], 1)[:, :, 1])
+sum(iradon(sinogram_big, [pi/4f0])[:, :, 1])
 
 # ╔═╡ b1607e05-d9ac-46cc-83b0-0f2b2c433059
-simshow(iradon(sinogram_big, [3.4], 1)[:, :, 1])
+simshow(iradon(sinogram_big, [3.4f0])[:, :, 1])
 
 # ╔═╡ 773e3961-e398-4d4b-a5e6-76b457561976
-simshow(iradon(sinogram_big, [0], 1)[:, :, 1])
+simshow(iradon(sinogram_big, [0])[:, :, 1])
 
 # ╔═╡ 5103d58e-34c8-4b9c-a0ab-c4f88f436186
 md"# Radon"
@@ -115,11 +115,11 @@ begin
 	i = 1
 	for θ in angles
 		cc = size(sg, 1) ÷ 2 + 1
-		x,y = (12, 9) .- (cc)
+		x,y = (11, 8) .- (cc)
 	
-		x,y = [cos(θ) sin(θ); -sin(θ) cos(θ)] * [x, y]
+		y,x = [cos(θ) sin(θ); -sin(θ) cos(θ)] * [x, y]
 
-		c =  cc + x - 1 + 1f-8
+		c =  cc + x + 1f-8
 
 		c1 = floor(Int, c)
 		c2 = ceil(Int, c)
@@ -130,14 +130,20 @@ begin
 	end
 end
 
+# ╔═╡ e8f4af35-d908-4b0d-b5cd-6332a6a78964
+theory
+
+# ╔═╡ a9719576-ce8a-4adf-95e2-18e748bd5a02
+15 ÷ 2
+
+# ╔═╡ 5bceb117-c839-4bfb-84fe-2a92be024fa6
+size(sg)
+
 # ╔═╡ d35fcf11-fe18-494e-b5af-c5cba4b0a1a3
 simshow(theory[:, :, 1])
 
 # ╔═╡ a3c4fd5b-a297-4875-8389-b42d82fc0dfc
-≈(sg, theory, rtol=0.1)
-
-# ╔═╡ 3eead087-8400-4a22-9ef2-fc74a5c247ff
-
+≈(sg, theory, rtol=0.3)
 
 # ╔═╡ 937726a1-64af-4fac-8d86-d115533183a0
 begin
@@ -159,7 +165,7 @@ simshow(radon(array2, [pi/2])[:, :, 1])
 simshow(array[:, :, 1])
 
 # ╔═╡ 00b91330-5aca-4c3f-9d35-3164fabaea04
-sg2 = radon(array, [pi/2, pi + pi/2, 2pi+ pi/2], 1.0)
+sg2 = radon(array, [pi/2, pi + pi/2, 2pi+ pi/2])
 
 # ╔═╡ 7c75d09d-317c-4788-9df1-2644ef4d19fe
 rad2deg(2.356194490192345)
@@ -174,10 +180,10 @@ exp(-9)
 simshow(sg2[:, :, 1])
 
 # ╔═╡ c242d6c2-b19c-4cc1-b7dd-d54394eddfc6
-@show radon(array, range(0, pi, 8), 1.0);
+@show radon(array, range(0, pi, 8));
 
 # ╔═╡ 08f287ca-21e9-4ffe-b21d-ec036aca39f4
-a = radon(array, [0, pi/2, pi, pi + pi/2,2pi], 1.0);
+a = radon(array, [0, pi/2, pi, pi + pi/2,2pi]);
 
 # ╔═╡ f07ccb05-518d-43f2-bbdf-c2851fa1b6aa
 maximum(a, dims=1)
@@ -192,7 +198,7 @@ simshow(a[:, :, 1])
 simshow(array[:, :, 1])
 
 # ╔═╡ 18c39411-899a-445b-8433-b524cf395ea0
-radon(zeros((128, 128, 1)), range(0, 2pi, 300), 1.0)
+radon(zeros((128, 128, 1)), range(0, 2pi, 300))
 
 # ╔═╡ Cell order:
 # ╠═1f8b489e-1028-11ee-3580-150afa948930
@@ -222,11 +228,13 @@ radon(zeros((128, 128, 1)), range(0, 2pi, 300), 1.0)
 # ╠═2312af02-941f-4ab2-b8b8-02ba437bf5d0
 # ╠═efe3724b-0ec0-48db-98ae-8ae7d924419a
 # ╠═a1a808eb-316d-4e6b-b42a-11c45b55ae36
+# ╠═e8f4af35-d908-4b0d-b5cd-6332a6a78964
 # ╠═13d70988-d480-4915-b9e6-67622d7dbca8
 # ╠═fba7aedc-612c-40fd-b7b2-ebb1c364faa2
+# ╠═a9719576-ce8a-4adf-95e2-18e748bd5a02
+# ╠═5bceb117-c839-4bfb-84fe-2a92be024fa6
 # ╠═d35fcf11-fe18-494e-b5af-c5cba4b0a1a3
 # ╠═a3c4fd5b-a297-4875-8389-b42d82fc0dfc
-# ╠═3eead087-8400-4a22-9ef2-fc74a5c247ff
 # ╠═937726a1-64af-4fac-8d86-d115533183a0
 # ╠═8ce53564-3bdf-4ab7-9ec5-cd4560fdd4be
 # ╠═53baff4f-25a4-4659-9b08-ee0d6abf3d05
diff --git a/test/runtests.jl b/test/runtests.jl
index 21a1600..d8bf4ef 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -6,68 +6,33 @@ using Test
 
     @testset "radon without absorption" begin
 
-	    array = zeros((16, 16,1))
+        array = zeros((16, 16,1))
 	    array[12,9] = 1
+   
         angles = range(0, 2pi, 100)
         sg = radon(array, angles)
-        begin
-	        theory = zeros(size(sg))
+    	theory = zeros(size(sg))
+
+    	i = 1
+    	for θ in angles
+    		cc = size(sg, 1) ÷ 2 + 1
+    		x,y = (11, 8) .- (cc)
+    	
+    		y,x = [cos(θ) sin(θ); -sin(θ) cos(θ)] * [x, y]
+    
+    		c =  cc + x + 1f-8
+    
+    		c1 = floor(Int, c)
+    		c2 = ceil(Int, c)
+    
+    		theory[c1, i] += (c2 - c)
+    		theory[c2, i] += (c - c1)
+    		i += 1
+    	end
+    
+        @test ≈(sg, theory, rtol=0.3)
 
-	        i = 1
-	        for θ in angles
-	        	cc = size(sg, 1) ÷ 2 + 1
-	        	x,y = (12, 9) .- (cc)
 
-	        	x,y = [cos(θ) sin(θ); -sin(θ) cos(θ)] * [x, y]
-
-	        	c =  cc + x - 1 + 1f-8
-
-	        	c1 = floor(Int, c)
-	        	c2 = ceil(Int, c)
-
-	        	theory[c1, i] += (c2 - c)
-	        	theory[c2, i] += (c - c1)
-	        	i += 1
-	        end
-        end
-
-        @test ≈(sg, theory, rtol=0.1)
-
-
-        begin
-        	array2 = zeros((16, 16,1))
-        	array2[12,9] = 1
-        	array2[12, 12] = 1
-        end
-
-
-        @test radon(array, range(0, pi, 8), 1.0) ≈ [0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0013106791246981077 0.0059024956158884164; 0.0 0.0 0.0 0.0 0.0 0.00035964724781605066 0.00023070310021843104 0.0; 0.0 0.0 0.0 0.0 0.00010934973082693491 4.091501530026382e-5 0.0 0.0; 0.0 0.0 0.0 3.8440644349164666e-5 3.8440644349164666e-5 0.0 0.0 0.0; 0.0 0.0 4.0915015300263786e-5 0.00010934973082693491 0.0 0.0 0.0 0.0; 0.0 0.00023070310021842976 0.0003596472478160496 0.0 0.0 0.0 0.0 0.0; 0.0059024956158884164 0.001310679124698108 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0;;;]
-
-        @test radon(array, range(0, pi, 8), 1.0) ≈ [0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0013106791246981077 0.0059024956158884164; 0.0 0.0 0.0 0.0 0.0 0.00035964724781605066 0.00023070310021843104 0.0; 0.0 0.0 0.0 0.0 0.00010934973082693491 4.091501530026382e-5 0.0 0.0; 0.0 0.0 0.0 3.8440644349164666e-5 3.8440644349164666e-5 0.0 0.0 0.0; 0.0 0.0 4.0915015300263786e-5 0.00010934973082693491 0.0 0.0 0.0 0.0; 0.0 0.00023070310021842976 0.0003596472478160496 0.0 0.0 0.0 0.0 0.0; 0.0059024956158884164 0.001310679124698108 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0;;;]
-
-    end
-
-
-
-
-    @testset "iradon without absorption" begin
-        sinogram = zeros((10, 2, 1))
-	    sinogram[5, :, 1] .= 1
-        
-        @test iradon(sinogram, [0.0f0, pi / 2.0f0]) == [0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0; 0.0 0.5 0.5 0.5 0.5 1.0 0.5 0.5 0.5 0.5; 0.0 0.0 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0;;;]
-        @test iradon(sinogram, [0]) == [0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0;;;]
-
-    end
-
-    @testset "iradon with absorption" begin
-        sinogram = zeros((10, 2, 1))
-	    sinogram[5, :, 1] .= 1
-        
-        @test iradon(sinogram, [0], 1.0) ≈ [0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.00033546262 0.000911882 0.0024787523 0.006737947 0.01831564 0.049787067 0.13533528 0.36787945 1.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0;;;]
-
-        @test iradon(sinogram, [pi], 1.0) ≈ [0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 1.0 0.36787945 0.13533528 0.049787067 0.01831564 0.006737947 0.0024787523 0.000911882 0.00033546262; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0;;;]
-
-        @test iradon(sinogram, [pi + pi / 2], 1.0) ≈ [0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.00033546262 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.000911882 9.196053f-19 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.0024787523 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.006737947 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.01831564 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.049787067 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 0.13533528 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 3.7099527f-16 0.36787945 0.0 0.0 0.0 0.0; 0.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 0.0 0.0;;;]
     end
 
 end