metaprogramming error

scale_sparse.jl

function scale_sd!(A::SparseMatrixCSC; corrected=true)
    n = size(A, 1)
    if corrected
        sdcall = :(sqrt(sum(vi^2 for vi in v) / (n - 1) - (n / (n - 1)) * mn^2))
    else
        sdcall = :(sqrt(sum(vi^2 for vi in v) / n - mn^2))
    end
    for j in 1:size(A, 2)
        k = A.colptr[j]:(A.colptr[j+1] - 1)
        if length(k) == 0
            continue
        end
        v = view(A.nzval, k)
        mn = mean(v) * (length(k) / n)
        A.nzval[k] .= v ./ eval(sdcall)
    end
    return A
end

A = sprand(10, 10, 0.1);
scale_sd!(A);

#ERROR: UndefVarError: v not defined
#Stacktrace:
# [1] eval(::Module, ::Any) at ./boot.jl:288
# [2] eval(::Any) at ./boot.jl:287
# [3] #scale_sd!#1(::Bool, ::Function, ::SparseMatrixCSC{Float64,Int64}) at ./REPL[1]:15
# [4] scale_sd!(::SparseMatrixCSC{Float64,Int64}) at ./REPL[1]:2