fixes a pivot bug

Author: RafaelDavidMohr

src/siggb/linear_algebra.jl

@@ -19,7 +19,7 @@ function echelonize!(matrix::MacaulayMatrix,
         hash2col[col2hash[i]] = MonIdx(i)
     end
 
-    @inbounds for i in 2:matrix.nrows
+    @inbounds for i in 1:matrix.nrows
         row_ind = matrix.sig_order[i]
 
         row_cols = matrix.rows[row_ind]
@@ -34,7 +34,10 @@ function echelonize!(matrix::MacaulayMatrix,
             does_red = !iszero(pividx) && rev_sigorder[pividx] < i
             does_red && break
         end
-        !does_red && continue
+        if !does_red
+            pivots[l_col_idx] = row_ind
+            continue
+        end
 
         # buffer the row
         row_coeffs = matrix.coeffs[row_ind]

src/siggb/update.jl

@@ -76,7 +76,6 @@ function update_basis!(basis::Basis,
             insert_in_basis_hash_table_pivots!(row, basis_ht, symbol_ht)
             lm = basis_ht.exponents[first(row)]
             s = new_sig
-            # println("new $s, $(lm.exps)")
 
             # add everything to basis
             l = basis.basis_load + 1