scripts/gray/visual.py: degrade instead of failing on missing files

scripts/gray/visual.py

@@ -39,6 +39,20 @@ def cli_args() -> argparse.Namespace:
     return parser.parse_args()
 
 
+def placeholder(ax: plt.Axes, text: str):
+    '''
+    Puts a placeholder text at the center of an axis
+    '''
+    left, width = .25, .5
+    bottom, height = .25, .5
+    right = left + width
+    top = bottom + height
+
+    ax.text(0.5*(left+right), 0.5*(top+bottom), text,
+            horizontalalignment='center',
+            verticalalignment='center')
+
+
 def align_yaxis(*axes: [plt.Axes]):
     '''
     Aligns the origins of two axes
@@ -116,6 +130,7 @@ def plot_poloidal(inputs: Path, outputs: Path, ax: plt.Axes):
     ax.set_ylabel('$z$ / m')
 
     # load flux surfaces
+    try:
         surfaces = gray.read_table(outputs / 'flux-surfaces.71.txt')
         surfaces = surfaces.reshape(-1, int(surfaces['i'].max()))
 
@@ -140,6 +155,8 @@ def plot_poloidal(inputs: Path, outputs: Path, ax: plt.Axes):
                       fontsize=10, fmt={1: label})
         ax.plot(np.nan, np.nan, '--', color='xkcd:ocean blue',
                 label='rational surfaces')
+    except FileNotFoundError:
+        pass
 
     # load limiter
     limiter = gray.get_limiter(conf, inputs)
@@ -186,12 +203,15 @@ def plot_toroidal(inputs: Path, outputs: Path, ax: plt.Axes):
     limiter = gray.get_limiter(conf, inputs)
 
     # plot plasma boundary
+    try:
         surfaces = gray.read_table(outputs / 'flux-surfaces.71.txt')
         boundary = surfaces[np.isclose(surfaces['ψ_n'], 1, 1e-3)]
 
         # plot plasma boundary
         plot_circle(ax, radius=boundary['R'].min(), color='xkcd:slate gray')
         plot_circle(ax, radius=boundary['R'].max(), color='xkcd:slate gray')
+    except FileNotFoundError:
+        pass
 
     # plot limiter
     if limiter[0].size > 0:
@@ -374,23 +394,30 @@ def plot_inputs(inputs: Path, outputs: Path, axes: [plt.Axes]):
     '''
     from matplotlib.colors import TwoSlopeNorm
 
-    maps = gray.read_table(outputs / 'inputs-maps.72.txt')
+    conf = gray.read_conf(inputs / 'gray.ini')
 
+    try:
+        maps = gray.read_table(outputs / 'inputs-maps.72.txt')
         # filter valid points
         maps = maps[maps['ψ_n'] > 0]
         flux = maps['R'], maps['z'], maps['ψ_n']
+    except FileNotFoundError:
+        maps = None
+        placeholder(axes['B'], 'inputs-maps.72.txt not found')
 
     # contour levels
+    ψ_max = maps['ψ_n'].max() if maps is not None else 1.2
     inner_levels = np.linspace(0, 0.99, 8)
-    outer_levels = np.linspace(0.9991, maps['ψ_n'].max()*0.99, 6)
+    outer_levels = np.linspace(0.9991, ψ_max*0.99, 6)
     all_levels = np.concatenate([inner_levels, outer_levels])
 
     # contour style
-    norm = TwoSlopeNorm(vmin=0, vcenter=1, vmax=maps['ψ_n'].max())
+    norm = TwoSlopeNorm(vmin=0, vcenter=1, vmax=ψ_max)
     cmap = plt.cm.RdYlGn_r
     borders = dict(colors='xkcd:grey', linestyles='-', linewidths=0.8)
 
     # interpolated equilibrium
+    if maps is not None:
         interp = axes['B']
         interp.set_title('poloidal flux', loc='right')
         interp.set_xlabel('$R$ / m')
@@ -401,7 +428,6 @@ def plot_inputs(inputs: Path, outputs: Path, axes: [plt.Axes]):
         interp.plot(np.nan, np.nan, c='xkcd:slate gray', label='plasma boundary')
 
         # add limiter
-    conf = gray.read_conf(inputs / 'gray.ini')
         limiter = gray.get_limiter(conf, inputs)
         interp.plot(*limiter, c='xkcd:black', label='limiter')
 
@@ -418,14 +444,18 @@ def plot_inputs(inputs: Path, outputs: Path, axes: [plt.Axes]):
         orig.plot(*eqdsk.limiter, c='xkcd:black')
         orig.plot(*eqdsk.boundary, c='xkcd:slate gray')
     else:
-        orig.axis('off')
+        placeholder(orig, 'not an EQDSK')
 
     # colorbar
     bar = plt.colorbar(plt.cm.ScalarMappable(norm, cmap), cax=axes['C'])
     bar.set_label(label='normalised poloidal flux', labelpad=10)
 
     # Plasma radial profiles
+    try:
         profiles = gray.read_table(outputs / 'kinetic-profiles.55.txt')
+    except FileNotFoundError:
+        placeholder(axes['D'], 'kinetic-profiles.55.txt not found')
+        return
 
     axes['D'].set_title('plasma profiles', loc='right')
     add_alt_axis(axes['D'], profiles['ρ_t'], profiles['ψ_n']**0.5,