diff --git a/app-proto/src/diagnostics.rs b/app-proto/src/diagnostics.rs
index 0aa46c3..47a9086 100644
--- a/app-proto/src/diagnostics.rs
+++ b/app-proto/src/diagnostics.rs
@@ -50,8 +50,11 @@ fn RealizationStatus() -> View {
     }
 }
 
-fn into_time_point((step, value): (usize, f64)) -> Vec<Option<f64>> {
-    vec![Some(step as f64), Some(value)]
+fn into_log10_time_point((step, value): (usize, f64)) -> Vec<Option<f64>> {
+    vec![
+        Some(step as f64),
+        if value == 0.0 { None } else { Some(value.abs().log10()) }
+    ]
 }
 
 // the loss history from the last realization
@@ -69,15 +72,15 @@ fn LossHistory() -> View {
                     .iter()
                     .enumerate()
                     .map(|(step, &loss)| (step, loss))
-                    .map(into_time_point)
+                    .map(into_log10_time_point)
                     .collect()
             );
             
-            // initialize the chart axes and series
+            // initialize the chart axes
             let step_axis = Axis::new()
                 .type_(AxisType::Category)
                 .boundary_gap(false);
-            let scaled_loss_axis = Axis::new().type_(AxisType::Log);
+            let scaled_loss_axis = Axis::new();
             
             // load the chart data. when there's no history, we load the data
             // point (0, None) to clear the chart. it would feel more natural to
@@ -116,9 +119,8 @@ fn SpectrumHistory() -> View {
     on_mount(move || {
         create_effect(move || {
             // get the spectrum of the Hessian at each step, split into its
-            // positive and negative parts. throw away eigenvalues that are
-            // close to zero
-            const ZERO_THRESHOLD: f64 = 1e-6;
+            // positive and negative parts. exact zero eigenvalues will be
+            // filtered out by `into_log10_time_point` later
             let (
                 hess_eigvals_pos,
                 hess_eigvals_neg
@@ -127,22 +129,19 @@ fn SpectrumHistory() -> View {
                     .iter()
                     .enumerate()
                     .map(
-                        |(step, eigvals)| eigvals
-                            .iter()
-                            .filter(|&&val| val.abs() > ZERO_THRESHOLD)
-                            .map(
-                                move |&val| (step, val)
-                            )
+                        |(step, eigvals)| eigvals.iter().map(
+                            move |&val| (step, val)
+                        )
                     )
                     .flatten()
                     .partition(|&(_, val)| val > 0.0)
             );
             
-            // initialize the chart axes and series
+            // initialize the chart axes
             let step_axis = Axis::new()
                 .type_(AxisType::Category)
                 .boundary_gap(false);
-            let eigval_axis = Axis::new().type_(AxisType::Log);
+            let eigval_axis = Axis::new();
             
             // load the chart data. when there's no history, we load the data
             // point (0, None) to clear the chart. it would feel more natural to
@@ -154,7 +153,7 @@ fn SpectrumHistory() -> View {
                     if hess_eigvals_pos.len() > 0 {
                         hess_eigvals_pos
                             .into_iter()
-                            .map(into_time_point)
+                            .map(into_log10_time_point)
                             .collect()
                     } else {
                         vec![vec![Some(0.0), None::<f64>]]
@@ -167,8 +166,7 @@ fn SpectrumHistory() -> View {
                     if hess_eigvals_neg.len() > 0 {
                         hess_eigvals_neg
                             .into_iter()
-                            .map(|(step, val)| (step, -val))
-                            .map(into_time_point)
+                            .map(into_log10_time_point)
                             .collect()
                     } else {
                         vec![vec![Some(0.0), None::<f64>]]