viz: fix colorbar label width to 11 chars for negative scientific notation

Author: sbryngelson

toolchain/mfc/viz/tui.py

@@ -241,26 +241,8 @@ def render(self):  # pylint: disable=too-many-branches,too-many-locals,too-many-
         h_plot_avail = max(self.size.height - 4, 4)  # -2 border, -2 header+footer
 
         # Right side: gap + gradient strip + value labels.
-        # Compute label width dynamically so long labels (e.g. "-2.26e-05")
-        # are never truncated.  Use the full-data range as a conservative
-        # estimate — it is always ≥ the zoomed-window range.
-        if self._vmin is not None and self._vmax is not None:
-            _vmin_est, _vmax_est = self._vmin, self._vmax
-        elif self._data is not None:
-            _finite = self._data[np.isfinite(self._data)]
-            _vmin_est = float(_finite.min()) if _finite.size else 0.0
-            _vmax_est = float(_finite.max()) if _finite.size else 1.0
-        else:
-            _vmin_est, _vmax_est = 0.0, 1.0
-        if _vmax_est <= _vmin_est:
-            _vmax_est = _vmin_est + 1e-10
-        _mid_est = (_vmin_est + _vmax_est) / 2
-        _CB_LBL = max(
-            len(f" {_vmax_est:.3g}"),
-            len(f" {_vmin_est:.3g}"),
-            len(f" {_mid_est:.3g}"),
-        )
-        _CB_GAP, _CB_W = 1, 2
+        # 11 chars fits negative scientific notation e.g. " -2.26e-05".
+        _CB_GAP, _CB_W, _CB_LBL = 1, 2, 11
         w_map_avail = max(w_plot - _CB_GAP - _CB_W - _CB_LBL, 4)
 
         # Preserve the physical x/y aspect ratio.