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fingolfin merged 1 commit into from
Jun 17, 2025
Merged

Print sheaf cohomology tables more compactly #5004

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192 changes: 95 additions & 97 deletions src/Modules/ModulesGraded.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -1528,7 +1528,7 @@
step, min, maxv = b.reverse_direction ? (-1, maximum(first, x), minimum(first, x)) : (1, minimum(first, x), maximum(first, x))
column_widths = Dict()
for j in min:step:maxv
sum_col = sum(getindex(T, x[m]) for m in 1:length(x) if x[m][1] == j)
sum_col = sum(T[y] for y in x if y[1] == j)
col_width_from_sum = ndigits(abs(sum_col))
col_width_from_header = ndigits(abs(j))# + (j < 0 ? 1 : 0)
column_widths[j] = max(col_width_from_sum, col_width_from_header) + 2
Expand All @@ -1539,9 +1539,7 @@
ngens(parent(x[1][2])) > 1 && println(io, "Betti Table for component ", i)

# figure out width of first column
L = sort(unique!(collect(x[k][2][i] for k in 1:length(x))))
mi = minimum(L)
mx = maximum(L)
mi, mx = extrema(y[2][i] for y in x)
# 6 = length(degree); we take length of mi into account in case it is negative
first_column_width = max(6, ndigits(mi), ndigits(mx))

Expand All @@ -1565,7 +1563,7 @@
for j in mi:mx
print(io, lpad(j, first_column_width), ":")
for h in min:step:maxv
sum_current = sum([getindex(T, x[k]) for k in 1:length(x) if x[k][1] == h && x[k][2][i] == j])
sum_current = sum([T[y] for y in x if y[1] == h && y[2][i] == j])
@assert column_widths[h] - ndigits(sum_current) >= 2
print(io, " "^(column_widths[h] - ndigits(sum_current) - 2))
print(io, " ", sum_current == 0 ? "-" : sum_current)
Expand All @@ -1580,7 +1578,7 @@
# footer row
print(io, lpad("total", first_column_width), ":")
for i_total in min:step:maxv
sum_row = sum(getindex(T, x[j]) for j in 1:length(x) if x[j][1] == i_total)
sum_row = sum(T[y] for y in x if y[1] == i_total)
print(io, " ", sum_row)
if i_total != maxv
print(io, " "^(column_widths[i_total] - ndigits(sum_row)-1))
Expand Down Expand Up @@ -1608,10 +1606,10 @@
print(io, L1[k], " " ^ (s2 - ndigits(L1[k]) + (5 - s2)), ": ")
for h in min:step:max
partial_sum = 0
for i in 1:length(x)
current_sum = (coordinates(b.project) * transpose(coordinates(x[i][2])))[1]
if current_sum == L1[k] && x[i][1] == h
partial_sum += getindex(T, x[i])
for y in x
current_sum = (coordinates(b.project) * transpose(coordinates(y[2])))[1]
if current_sum == L1[k] && y[1] == h
partial_sum += T[y]

Check warning on line 1612 in src/Modules/ModulesGraded.jl

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src/Modules/ModulesGraded.jl#L1609-L1612 

Added lines #L1609 - L1612 were not covered by tests
end
end
if partial_sum == 0
Expand All @@ -1627,9 +1625,9 @@
print(io, "\n", "total: ")
for i in min:step:max
total_sum = 0
for j in 1:length(x)
if x[j][1] == i
total_sum += getindex(T, x[j])
for y in x
if y[1] == i
total_sum += T[y]

Check warning on line 1630 in src/Modules/ModulesGraded.jl

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src/Modules/ModulesGraded.jl#L1628-L1630 

Added lines #L1628 - L1630 were not covered by tests
end
end
print(io, total_sum, " " ^ (spaces - ndigits(total_sum) + 1))
Expand All @@ -1645,21 +1643,23 @@
# https://www.singular.uni-kl.de/Manual/4-3-1/sing_1827.htm#SEC1908
###############################################################################

mutable struct sheafCohTable
mutable struct SheafCohTable
twist_range::UnitRange{Int}
values::Matrix{Int}
end

function Base.getindex(st::sheafCohTable, ind...)
function Base.getindex(st::SheafCohTable, ind...)
row_ind = size(st.values, 1) - ind[1]
col_ind = ind[2] - first(st.twist_range) + 1
return st.values[row_ind, col_ind]
end

function Base.show(io::IO, table::sheafCohTable)
function Base.show(io::IO, table::SheafCohTable)
chi = [any(==(-1), col) ? -1 : sum(col) for col in eachcol(table.values)]
# pad every value in the table to this length
val_space_length = max(maximum(_ndigits, table.values), maximum(_ndigits, chi))
val_space_length = max(maximum(_ndigits, table.values), maximum(_ndigits, chi)) + 1
# consider table.twist_range as well
# handle sign!
nrows = size(table.values, 1)

# rows to print
Expand All @@ -1668,18 +1668,19 @@
chi_print = [_shcoh_string_rep(v, val_space_length) for v in chi]

# row labels
row_label_length = max(_ndigits(nrows - 1), 3) + 3
row_label_length = max(ndigits(nrows - 1), 5) + 1
for i in 1:nrows
pushfirst!(print_rows[i], rpad("$(nrows-i): ", row_label_length, " "))
pushfirst!(print_rows[i], lpad("$(nrows-i):", row_label_length, " "))
end
pushfirst!(chi_print, rpad("chi: ", row_label_length, " "))
pushfirst!(chi_print, lpad("chi:", row_label_length, " "))

# header
header = [lpad(v, val_space_length, " ") for v in table.twist_range]
pushfirst!(header, rpad("twist:", row_label_length, " "))
pushfirst!(header, lpad("twist:", row_label_length, " "))

println(io, header...)
size_row = sum(length, first(print_rows))

println(io, header...)
println(io, repeat("-", size_row))
for rw in print_rows
println(io, rw...)
Expand Down Expand Up @@ -1728,14 +1729,14 @@
julia> M = cokernel(map(FI, 2));

julia> tbl = sheaf_cohomology(M, -6, 2)
twist: -6 -5 -4 -3 -2 -1 0 1 2
------------------------------------------
3: 70 36 15 4 - - - - *
2: * - - - - - - - -
1: * * - - - - 1 - -
0: * * * - - - - - 6
------------------------------------------
chi: * * * 4 - - 1 - *
twist: -6 -5 -4 -3 -2 -1 0 1 2
---------------------------------
3: 70 36 15 4 - - - - *
2: * - - - - - - - -
1: * * - - - - 1 - -
0: * * * - - - - - 6
---------------------------------
chi: * * * 4 - - 1 - *

julia> tbl[0, 2]
6
Expand All @@ -1744,33 +1745,31 @@
1

julia> sheaf_cohomology(M, -9, 5)
twist: -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5
---------------------------------------------------------------------------------
3: 280 189 120 70 36 15 4 - - - - - * * *
2: * - - - - - - - - - - - - * *
1: * * - - - - - - - 1 - - - - *
0: * * * - - - - - - - - 6 20 45 84
---------------------------------------------------------------------------------
chi: * * * 70 36 15 4 - - 1 - 6 * * *
```
twist: -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5
------------------------------------------------------------------
3: 280 189 120 70 36 15 4 - - - - - * * *
2: * - - - - - - - - - - - - * *
1: * * - - - - - - - 1 - - - - *
0: * * * - - - - - - - - 6 20 45 84
------------------------------------------------------------------
chi: * * * 70 36 15 4 - - 1 - 6 * * *

```jldoctest
julia> R, x = polynomial_ring(QQ, :x => 1:5);

julia> S, _ = grade(R);

julia> F = graded_free_module(S, 1);

julia> sheaf_cohomology(F, -8, 3, algorithm = :loccoh)
twist: -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3
------------------------------------------------------
4: 35 15 5 1 - - - - - - - -
3: - - - - - - - - - - - -
2: - - - - - - - - - - - -
1: - - - - - - - - - - - -
0: - - - - - - - - 1 5 15 35
------------------------------------------------------
chi: 35 15 5 1 - - - - 1 5 15 35
twist: -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3
------------------------------------------
4: 35 15 5 1 - - - - - - - -
3: - - - - - - - - - - - -
2: - - - - - - - - - - - -
1: - - - - - - - - - - - -
0: - - - - - - - - 1 5 15 35
------------------------------------------
chi: 35 15 5 1 - - - - 1 5 15 35
```
"""
function sheaf_cohomology(M::ModuleFP{T},
Expand Down Expand Up @@ -1806,26 +1805,26 @@
julia> F = graded_free_module(R, 1);

julia> Oscar._sheaf_cohomology_bgg(F, -7, 2)
twist: -7 -6 -5 -4 -3 -2 -1 0 1 2
----------------------------------------------
4: 15 5 1 - - - * * * *
3: * - - - - - - * * *
2: * * - - - - - - * *
1: * * * - - - - - - *
0: * * * * - - - 1 5 15
----------------------------------------------
chi: * * * * - - * * * *
twist: -7 -6 -5 -4 -3 -2 -1 0 1 2
------------------------------------
4: 15 5 1 - - - * * * *
3: * - - - - - - * * *
2: * * - - - - - - * *
1: * * * - - - - - - *
0: * * * * - - - 1 5 15
------------------------------------
chi: * * * * - - * * * *

julia> sheaf_cohomology(F, -11, 6)
twist: -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
------------------------------------------------------------------------------------------------
4: 210 126 70 35 15 5 1 - - - - - - - * * * *
3: * - - - - - - - - - - - - - - * * *
2: * * - - - - - - - - - - - - - - * *
1: * * * - - - - - - - - - - - - - - *
0: * * * * - - - - - - - 1 5 15 35 70 126 210
------------------------------------------------------------------------------------------------
chi: * * * * 15 5 1 - - - - 1 5 15 * * * *
twist: -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
------------------------------------------------------------------------------
4: 210 126 70 35 15 5 1 - - - - - - - * * * *
3: * - - - - - - - - - - - - - - * * *
2: * * - - - - - - - - - - - - - - * *
1: * * * - - - - - - - - - - - - - - *
0: * * * * - - - - - - - 1 5 15 35 70 126 210
------------------------------------------------------------------------------
chi: * * * * 15 5 1 - - - - 1 5 15 * * * *
```

```jldoctest
Expand All @@ -1848,14 +1847,14 @@
julia> M = cokernel(map(FI, 2));

julia> tbl = sheaf_cohomology(M, -6, 2, algorithm = :loccoh)
twist: -6 -5 -4 -3 -2 -1 0 1 2
------------------------------------------
3: 70 36 15 4 - - - - -
2: - - - - - - - - -
1: - - - - - - 1 - -
0: - - - - - - - - 6
------------------------------------------
chi: 70 36 15 4 - - 1 - 6
twist: -6 -5 -4 -3 -2 -1 0 1 2
---------------------------------
3: 70 36 15 4 - - - - -
2: - - - - - - - - -
1: - - - - - - 1 - -
0: - - - - - - - - 6
---------------------------------
chi: 70 36 15 4 - - 1 - 6

julia> tbl[3, -6]
70
Expand All @@ -1874,7 +1873,7 @@
values = Singular.LibSheafcoh.sheafCohBGGregul_w(sing_mod,
l, h, reg,
weights)
return sheafCohTable(l:h, values)
return SheafCohTable(l:h, values)
end

@doc raw"""
Expand Down Expand Up @@ -1909,14 +1908,14 @@
julia> M = cokernel(map(FI, 2));

julia> tbl = Oscar._sheaf_cohomology_loccoh(M, -6, 2)
twist: -6 -5 -4 -3 -2 -1 0 1 2
------------------------------------------
3: 70 36 15 4 - - - - -
2: - - - - - - - - -
1: - - - - - - 1 - -
0: - - - - - - - - 6
------------------------------------------
chi: 70 36 15 4 - - 1 - 6
twist: -6 -5 -4 -3 -2 -1 0 1 2
---------------------------------
3: 70 36 15 4 - - - - -
2: - - - - - - - - -
1: - - - - - - 1 - -
0: - - - - - - - - 6
---------------------------------
chi: 70 36 15 4 - - 1 - 6

julia> tbl[3, -6]
70
Expand All @@ -1931,15 +1930,15 @@
julia> F = graded_free_module(R, 1);

julia> Oscar._sheaf_cohomology_loccoh(F, -7, 2)
twist: -7 -6 -5 -4 -3 -2 -1 0 1 2
----------------------------------------------
4: 15 5 1 - - - - - - -
3: - - - - - - - - - -
2: - - - - - - - - - -
1: - - - - - - - - - -
0: - - - - - - - 1 5 15
----------------------------------------------
chi: 15 5 1 - - - - 1 5 15
twist: -7 -6 -5 -4 -3 -2 -1 0 1 2
------------------------------------
4: 15 5 1 - - - - - - -
3: - - - - - - - - - -
2: - - - - - - - - - -
1: - - - - - - - - - -
0: - - - - - - - 1 5 15
------------------------------------
chi: 15 5 1 - - - - 1 5 15
```
"""
function _sheaf_cohomology_loccoh(M::ModuleFP{T},
Expand All @@ -1951,7 +1950,7 @@
values = Singular.LibSheafcoh.sheafCoh_w(sing_mod,
l, h,
weights)
return sheafCohTable(l:h, values)
return SheafCohTable(l:h, values)
end

# helper functions
Expand All @@ -1962,9 +1961,8 @@
end

function _ndigits(val::Int)
iszero(val) && return 3
val == -1 && return 3
return Int(floor(log10(val))) + 3
val == -1 && return 1 # is display as '*'
return ndigits(val)
end

function _weights_and_sing_mod(M::ModuleFP{T}) where {T <: MPolyDecRingElem}
Expand Down
36 changes: 18 additions & 18 deletions test/book/cornerstones/algebraic-geometry/char3-surface-2.jlcon
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Original file line number Diff line number Diff line change
Expand Up @@ -57,23 +57,23 @@ julia> degree(I)
julia> MI = ideal_as_module(I);

julia> sheaf_cohomology(MI, -2, 8, algorithm = :loccoh)
twist: -2 -1 0 1 2 3 4 5 6 7 8
-------------------------------------------------------------
4: - - - - - - - - - - -
3: 30 10 - - - - - - - - -
2: - - - 2 - - - - - - -
1: - - - - 1 5 5 - - - -
0: - - - - - - - 5 32 84 170
-------------------------------------------------------------
chi: 30 10 - 2 1 5 5 5 32 84 170
twist: -2 -1 0 1 2 3 4 5 6 7 8
--------------------------------------------------
4: - - - - - - - - - - -
3: 30 10 - - - - - - - - -
2: - - - 2 - - - - - - -
1: - - - - 1 5 5 - - - -
0: - - - - - - - 5 32 84 170
--------------------------------------------------
chi: 30 10 - 2 1 5 5 5 32 84 170

julia> sheaf_cohomology(MI, -2, 8)
twist: -2 -1 0 1 2 3 4 5 6 7 8
-------------------------------------------------------------
4: - - - - - - - * * * *
3: * 10 - - - - - - * * *
2: * * - 2 - - - - - * *
1: * * * - 1 5 5 - - - *
0: * * * * - - - 5 32 84 170
-------------------------------------------------------------
chi: * * * * 1 5 5 * * * *
twist: -2 -1 0 1 2 3 4 5 6 7 8
--------------------------------------------------
4: - - - - - - - * * * *
3: * 10 - - - - - - * * *
2: * * - 2 - - - - - * *
1: * * * - 1 5 5 - - - *
0: * * * * - - - 5 32 84 170
--------------------------------------------------
chi: * * * * 1 5 5 * * * *
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