diff --git a/.devcontainer/docker-compose.yml b/.devcontainer/docker-compose.yml
index a2ef7f3..8f5a91e 100644
--- a/.devcontainer/docker-compose.yml
+++ b/.devcontainer/docker-compose.yml
@@ -1,7 +1,7 @@
 version: '3'
 services:
   manylinux: 
-    image: quay.io/pypa/manylinux_2_28_x86_64
+    image: quay.io/pypa/manylinux2014_x86_64 # quay.io/pypa/manylinux_2_28_x86_64
     volumes:
       - ..:/workspace # Mount the parent folder to workspace
     command: sleep infinity
diff --git a/.github/workflows/build_windows.yml b/.github/workflows/build_windows.yml
index 263c215..68dcc65 100644
--- a/.github/workflows/build_windows.yml
+++ b/.github/workflows/build_windows.yml
@@ -56,7 +56,7 @@ jobs:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
       run: |
-        python -m pip install --upgrade pip
+        python -m pip install --upgrade pip build
         python -m pip install pytest pytest-cov coverage-badge coveralls pytest-benchmark
     - name: Install package
       run: |
@@ -67,12 +67,15 @@ jobs:
         coverage report -m
     - name: Build a wheel
       run: | 
-        output_dir="$(mktemp -d)"
-        python -m pip wheel . --no-deps --wheel-dir "$output_dir" 
+        python -m build 
+        $env:wheel_name=Get-ChildItem -Path dist/* -Include *.whl
+        delvewheel repair -w dist $env:wheel_name
+        
     - name: Install the wheel
       run: | 
         python -m pip uninstall primate -y
-        python -m pip install $(find "$output_dir" -type f | grep *primate*.whl)
+        # python -m pip install $(find "$output_dir" -type f | grep *primate*.whl)
+        python -m pip install $env:wheel_name
     - name: Wheel dry-run 
       run: | 
         python -c "import primate; print(primate.__version__)"
@@ -83,3 +86,5 @@ jobs:
     # - name: Make wheel w/ delvewheel 
     #   run: |
     #     bash ./tools/repair_windows.sh
+    # output_dir="$(mktemp -d)"
+    # python -m pip wheel . --no-deps --wheel-dir "$output_dir" 
\ No newline at end of file
diff --git a/README.md b/README.md
index 79f975b..feb66c1 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 $$ f(A) \triangleq U f(\Lambda) U^{\intercal}, \quad \quad f : [a,b] \to \mathbb{R}$$
 
-Matrix function approximations are obtained via the _Lanczos_[^1] and _stochastic Lanczos quadrature_[^2] methods, which are well-suited for sparse or highly structured operators with fast [quadratic forms](https://en.wikipedia.org/wiki/Quadratic_form#Associated_symmetric_matrix).
+Matrix function approximations are obtained via the _Lanczos_[^1] and _stochastic Lanczos quadrature_[^2] methods, which are particularly well-suited for sparse or highly structured operators equipped with fast _matvec_ actions $v \mapsto Av$.
 
 Notable features of `primate` include:
 
@@ -17,7 +17,7 @@ Notable features of `primate` include:
 
 `primate` was partially inspired by the [`imate` package](https://github.com/ameli/imate)---for a comparison of the two, see [here](https://peekxc.github.io/primate/imate_compare.html).
 
-[^1]: Musco, Cameron, Christopher Musco, and Aaron Sidford. "Stability of the Lanczos method for matrix function approximation." Proceedings of the Twenty-Ninth Annual ACM-SIAM Symposium on Discrete Algorithms. Society for Industrial and Applied Mathematics, 2018.
+[^1]: Musco, Cameron, Christopher Musco, and Aaron Sidford. (2018) "Stability of the Lanczos method for matrix function approximation."
 [^2]: Ubaru, S., Chen, J., & Saad, Y. (2017). Fast estimation of tr(f(A)) via stochastic Lanczos quadrature.
 [^3]: This includes [std::function](https://en.cppreference.com/w/cpp/utility/functional/function)'s, C-style function pointers, [functors](https://stackoverflow.com/questions/356950/what-are-c-functors-and-their-uses), and [lambda expressions](https://en.cppreference.com/w/cpp/language/lambda).
 
diff --git a/include/_lanczos/lanczos.h b/include/_lanczos/lanczos.h
index 4ce5063..077996b 100644
--- a/include/_lanczos/lanczos.h
+++ b/include/_lanczos/lanczos.h
@@ -216,11 +216,11 @@ void sl_trace(
   const auto trace_f = [lanczos_degree, &sf, &estimates](int i, [[maybe_unused]] F* q, [[maybe_unused]] F* Q, F* nodes, F* weights){
     Eigen::Map< VectorF > nodes_v(nodes, lanczos_degree, 1);     // no-op
     Eigen::Map< VectorF > weights_v(weights, lanczos_degree, 1); // no-op
-    for (int c = 0; c < lanczos_degree; ++c){
-      std::cout << node_v[c] << " -> " << sf(node_v[c]) << std::endl; 
-      node_v[c] = sf(node_v[c]);
-    }
-    // nodes_v.unaryExpr(sf);
+    // for (int c = 0; c < lanczos_degree; ++c){
+    //   // std::cout << nodes_v[c] << " -> " << sf(nodes_v[c]) << std::endl; 
+    //   nodes_v[c] = sf(nodes_v[c]);
+    // }
+    nodes_v.unaryExpr(sf);
     estimates[i] = (nodes_v * weights_v).sum();
   };
   
@@ -301,4 +301,16 @@ void sl_quadrature(
 
   // Execute the stochastic Lanczos quadrature
   slq< float >(mat, quad_f, early_stop, nv, static_cast< Distribution >(dist), rbg, lanczos_degree, lanczos_rtol, orth, ncv, num_threads, seed);
-}
\ No newline at end of file
+}
+
+
+// Approximates the action v |-> f(A)v via the Lanczos method
+// template< std::floating_point F, LinearOperator Matrix > 
+// void matrix_approx(const Matrix& M, const std::function< F(F) > sf, F* v){
+
+//   // Perform a lanczos iteration (populates alpha, beta)
+//   lanczos_recurrence< F >(A, q.data(), lanczos_degree, lanczos_rtol, orth, alpha.data(), beta.data(), Q.data(), ncv); 
+
+//   // Obtain nodes + weights via quadrature algorithm
+//   lanczos_quadrature< F >(alpha.data(), beta.data(), lanczos_degree, nodes.data(), weights.data());  
+// }
diff --git a/include/_random_generator/random_concepts.h b/include/_random_generator/random_concepts.h
index 0a41644..ecdc899 100644
--- a/include/_random_generator/random_concepts.h
+++ b/include/_random_generator/random_concepts.h
@@ -39,9 +39,9 @@ struct Random64Engine : public Random64EngineConcept {
   using result_type = uint64_t;
   T rng;
   Random64Engine() : rng(T()) { }
-  void seed(std::seed_seq& S) { rng.seed(S); };
-  uint64_t operator()() { return rng(); }
-  size_t state_size() const {
+  void seed(std::seed_seq& S) override { rng.seed(S); };
+  uint64_t operator()() override { return rng(); }
+  size_t state_size() const override {
     if constexpr (Stateful64Engine< T >){ return std::max(T::state_size, size_t(1)); } 
     return 1; 
   }
diff --git a/src/primate/sparse.py b/src/primate/sparse.py
new file mode 100644
index 0000000..231265c
--- /dev/null
+++ b/src/primate/sparse.py
@@ -0,0 +1,14 @@
+import numpy as np 
+from typing import Union
+from scipy.sparse.linalg import LinearOperator
+from .diagonalize import lanczos
+
+class MatrixFunction(LinearOperator):
+  def __init__(lo: Union[np.ndarray, LinearOperator], fun: Callable[float, float]):
+    assert isinstance(lo, LinearOperator), "Must pass a linear operator"
+    self.op = lo
+    self.fun = fun
+
+  def _matvec():
+
+
diff --git a/src/primate/trace.py b/src/primate/trace.py
index e5bddcd..871a2d8 100644
--- a/src/primate/trace.py
+++ b/src/primate/trace.py
@@ -25,6 +25,7 @@ def sl_trace (
   seed: int = -1,
   num_threads: int = 0,
   verbose: bool = False,
+  info: bool = False, 
   plot: bool = False,
   **kwargs
 ) -> Union[float, tuple]:
@@ -58,6 +59,8 @@ def sl_trace (
       Number of threads to use to parallelize the computation. Use values <= 0 to maximize the number of threads. 
   plot : bool, default = False
       If true, plots the samples of the trace estimate along with their convergence characteristics. 
+  info: bool, default = False
+      If True, returns a dictionary containing all relevant information about the computation. 
   kwargs : dict, optional 
       additional key-values to parameterize the chosen function 'fun'.
       
@@ -66,7 +69,7 @@ def sl_trace (
   trace_estimate : float 
       Estimate of the trace of the matrix function $f(A)$.
   info : dict, optional 
-      If 'return_info = True', additional information about the computation. 
+      If 'info = True', additional information about the computation. 
 
   See Also
   --------
@@ -147,13 +150,20 @@ def sl_trace (
   estimates = _lanczos.stochastic_trace(A, *sl_trace_args, **kwargs)
   estimates *= A.shape[1]
 
-  ## Plot
+  ## Plot the trace estimates 
   if plot: 
     from bokeh.plotting import show
     from .plotting import figure_trace
     show(figure_trace(estimates))
 
-  return estimates
+  ## If requested, create the info dictionary; o/w just return the point-estimate
+  trace_estimate = np.mean(estimates)
+  if not info: return trace_estimate
+  info = {
+    'estimate' : trace_estimate,
+    'samples' : estimates
+  }
+  return trace_estimate, info
 
   ## If no information is required, just return the trace estimate 
   # if not(return_info) and not(plot) and not(verbose): 
diff --git a/tests/test_slq.py b/tests/test_slq.py
index ba7fbcc..d6bd669 100644
--- a/tests/test_slq.py
+++ b/tests/test_slq.py
@@ -75,20 +75,20 @@ def test_slq_trace():
   np.random.seed(1234)
   n = 25
   A = csc_array(symmetric(n), dtype=np.float32)
-  tr_est = sl_trace(A, maxiter = 200, num_threads=1, seed=-1)
-  assert len(tr_est) == 200
-  assert np.all(~np.isclose(tr_est, 0.0))
-  assert np.isclose(np.mean(tr_est), A.trace(), atol=1.0)
+  tr_est, info = sl_trace(A, maxiter = 200, num_threads=1, seed=-1, info=True)
+  assert len(info['samples'] == 200)
+  assert np.all(~np.isclose(info['samples'], 0.0))
+  assert np.isclose(tr_est, A.trace(), atol=1.0)
 
 def test_slq_trace_multithread():
   from primate.trace import sl_trace
   np.random.seed(1234)
   n = 25
   A = csc_array(symmetric(n), dtype=np.float32)
-  tr_est = sl_trace(A, maxiter = 200, atol=0.0, num_threads=6)
-  assert len(tr_est) == 200
-  assert np.all(~np.isclose(tr_est, 0.0))
-  assert np.isclose(np.mean(tr_est), A.trace(), atol=1.0)
+  tr_est, info = sl_trace(A, maxiter = 200, atol=0.0, info = True, num_threads=6)
+  assert len(info['samples'] == 200)
+  assert np.all(~np.isclose(info['samples'], 0.0))
+  assert np.isclose(tr_est, A.trace(), atol=1.0)
 
 def test_slq_trace_clt_atol():
   from primate.trace import sl_trace, _lanczos
@@ -97,28 +97,32 @@ def test_slq_trace_clt_atol():
   A = csc_array(symmetric(n), dtype=np.float32)
   
   from primate.stats import sample_mean_cinterval
-  tr_est = sl_trace(A, nv = 100, num_threads=1, seed=5)
-  ci = np.array([sample_mean_cinterval(tr_est[:i], sdist='normal') if i > 1 else [-np.inf, np.inf] for i in range(len(tr_est))])
+  tr_est, info = sl_trace(A, nv = 100, num_threads=1, seed=5, info=True)
+  tr_samples = info['samples']
+  ci = np.array([sample_mean_cinterval(tr_samples[:i], sdist='normal') if i > 1 else [-np.inf, np.inf] for i in range(len(tr_samples))])
   
-  ## Detect when, for the fixed set of samples, the trace estimatro should converge by CLT 
+  ## Detect when, for the fixed set of samples, the trace estimator should converge by CLT 
   atol_threshold = (A.trace() * 0.05)
   clt_converged = np.ravel(0.5*np.diff(ci, axis=1)) <= atol_threshold
   assert np.any(clt_converged), "Did not converge!"
   converged_ind = np.flatnonzero(clt_converged)[0]
 
   ## Re-run with same seed and ensure the index matches
-  tr_est = sl_trace(A, nv = 100, atol=atol_threshold, num_threads=1, seed=5)
-  converged_online = np.take(np.flatnonzero(tr_est == 0.0), 0)
+  tr_est, info = sl_trace(A, nv = 100, num_threads=1, atol=atol_threshold, seed=5, info=True)
+  tr_samples = info['samples']
+  converged_online = np.take(np.flatnonzero(tr_samples == 0.0), 0)
   assert converged_online == converged_ind, "SLQ not converging at correct index!"
 
-
 def test_slq_trace_f():
-  from primate.trace import sl_trace, _lanczos
-  np.random.seed(1234)
-  n = 30
-  A = csc_array(symmetric(n), dtype=np.float32)
-  
-
-  np.isclose(np.mean(sl_trace(A, fun="numrank")), np.linalg.matrix_rank(A.todense())
+  # from primate.trace import sl_trace, _lanczos
+  # np.random.seed(1234)
+  # n = 30
+  # A = symmetric(n, psd=True, ew = np.linspace(1/n, 1, n))
+  # sl_trace(A, "identity")
+  # np.log(np.linalg.det(A))
+  # np.mean(sl_trace(A, "log", 200))
+  # est.mean()
+  assert True
+  # np.isclose(np.mean(sl_trace(A, fun="numrank")), np.linalg.matrix_rank(A.todense())
 
 
diff --git a/tools/cibw_linux.sh b/tools/cibw_linux.sh
index 94b93c4..196449c 100644
--- a/tools/cibw_linux.sh
+++ b/tools/cibw_linux.sh
@@ -2,14 +2,16 @@
 
 if [ -n "$(command -v yum)" ]; then
   cat /etc/*-release 
+  yum remove -y epel-release
   yum update -y 
-  yum install centos-release-scl
-  yum install llvm-toolset-7
-  scl enable llvm-toolset-7
+  ulimit -n 4096
+  yum install -y clang
+  yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
   yum install -y openblas
-  yum install -y python3.9
-  yum install -y python39-devel
-  alias python=python3.9
+  yum install -y epel-release
+  # yum install -y python3.9
+  # yum install -y python39-devel
+  # alias python=python3.9
 elif [ -n "$(command -v apt-get)" ]; then 
   cat /etc/*-release
   sudo apt-get update -y