Merge pull request #14 from s-ccs/fix-studentt

fix studentt

Author: behinger

src/utils.jl

@@ -1,6 +1,6 @@
 function studentt!(out::AbstractMatrix, x::AbstractArray{<:Real,3}; kwargs...)
 
-    for (x_ch, o_ch) in zip(eachslice(x, dims = 1), eachslice(out, dims = 1))
+    for (x_ch, o_ch) in zip(eachslice(x, dims=1), eachslice(out, dims=1))
         #@debug size(x_ch),size(o_ch)
         studentt!(o_ch, x_ch; kwargs...)
     end
@@ -44,17 +44,17 @@ end
 function studentt!(out, x)
     #@debug size(out),size(x)
     mean!(out, x)
-    out .= out ./ (std(x, mean = out, dims = 2)[:, 1] ./ sqrt(size(x, 2) - 1))
+    out .= out ./ (std(x, mean=out, dims=2, corrected=true)[:, 1] ./ sqrt(size(x, 2)))
 end
 function studentt(x::AbstractMatrix)
     # more efficient than this one liner
     # studentt(x::AbstractMatrix) = (mean(x,dims=2)[:,1])./(std(x,dims=2)[:,1]./sqrt(size(x,2)-1))
-    μ = mean(x, dims = 2)[:, 1]
-    μ .= μ ./ (std(x, mean = μ, dims = 2)[:, 1] ./ sqrt(size(x, 2) - 1))
+    μ = mean(x, dims=2)[:, 1]
+    μ .= μ ./ (std(x, mean=μ, dims=2, corrected=true)[:, 1] ./ sqrt(size(x, 2)))
 end
 
 studentt(x::AbstractArray{<:Real,3}) =
-    dropdims(mapslices(studentt, x, dims = (2, 3)), dims = 3)
+    dropdims(mapslices(studentt, x, dims=(2, 3)), dims=3)
 
 """
 Permutation via random sign-flip
@@ -66,9 +66,26 @@ function sign_permute!(rng, x::AbstractArray)
 
     fl = rand(rng, [-1, 1], size(x, n))
 
-    for (flip, xslice) in zip(fl, eachslice(x; dims = n))
+    for (flip, xslice) in zip(fl, eachslice(x; dims=n))
         xslice .= xslice .* flip
     end
 
     return x
 end
+
+function batch_unpaired_ttest_unequal_var(x::AbstractArray, group)
+    x_reshaped = reshape(x, :, size(x, ndims(x)))
+    x₁ = x_reshaped[:, group]
+    x₂ = x_reshaped[:, .!group]
+
+    n₁, n₂ = size(x₁, 2), size(x₂, 2)
+    μ₁, μ₂ = mean(x₁, dims=2), mean(x₂, dims=2)
+    var₁, var₂ = var(x₁, dims=2, corrected=true), var(x₂, dims=2, corrected=true)
+
+    se = sqrt.(var₁ ./ n₁ .+ var₂ ./ n₂)
+    t_stat = (μ₁ .- μ₂) ./ se
+
+    # Reshape t_stat to match input dimensions (excluding last dim)
+    t_stat_reshaped = reshape(t_stat, size(x)[1:end-1])
+    return t_stat_reshaped
+end