Shorten the docs page titles

examples/01_cloud_in_cell_density.py

@@ -1,4 +1,4 @@
-"""Cloud-in-cell density in 1D
+"""Cloud-in-cell density
 
 Deposit a Maxwellian cloud of markers on a 1D grid and compare the density with the exact profile.
 

examples/02_beam_density_2d.py

@@ -1,4 +1,4 @@
-"""A beam's density in 2D
+"""Beam density in 2D
 
 Deposit a sheared, tilted Gaussian beam on a 2D grid, then smooth the deposit.
 

examples/04_deposit_gather_adjoint.py

@@ -1,6 +1,6 @@
-"""Deposit and gather are transposes
+"""Adjoint deposit and gather
 
-The scatter of marker values and the gather of a field use the same weights, so they are adjoint.
+Deposit and gather are transposes: the scatter of marker values and the gather of a field use the same weights, so they are adjoint.
 
 For any field $g$ on the nodes and charges $q_i$ at positions $x_i$,
 $\\sum_i q_i\\, g(x_i) = \\sum_n g_n \\rho_n$ with $\\rho$ the deposit of the charges. That is

examples/05_prescribed_electric_field.py

@@ -1,6 +1,6 @@
-"""An electric field from a prescribed potential
+"""Prescribed electric field
 
-Build $E = -\\nabla\\phi$ on a grid from a potential given as a function, here a three-electrode lens.
+An electric field from a prescribed potential: build $E = -\\nabla\\phi$ on a grid from a potential given as a function, here a three-electrode lens.
 
 `electric_field_from_potential` evaluates the potential on the nodes and differentiates it
 with second-order central differences. The lens has three cylinders, the middle one at

examples/06_vector_operations.py

@@ -1,6 +1,6 @@
-"""Vector fields: the E x B drift
+"""E x B drift
 
-Combine fields with arithmetic, `gradient`, `cross`, `dot` and `magnitude`: the drift velocity of a magnetized plasma.
+Vector fields: combine fields with arithmetic, `gradient`, `cross`, `dot` and `magnitude`: the drift velocity of a magnetized plasma.
 
 A potential hill $\\phi = \\phi_0 e^{-r^2/w^2}$ in a uniform magnetic field $B \\hat z$ makes
 the guiding centres drift with $v_E = E \\times B / B^2$, along the equipotentials. The

examples/08_periodic_seam.py

@@ -1,4 +1,4 @@
-"""A periodic axis
+"""Periodic axis
 
 On a periodic axis the last node neighbours the first: deposits and gathers wrap across the seam.
 

examples/11_test_particles.py

@@ -1,6 +1,6 @@
-"""Test particles in a fixed field
+"""Test particles
 
-Push charged particles through a field on a grid with a leapfrog scheme, gathering the field every step.
+Test particles in a fixed field: push charged particles through a field on a grid with a leapfrog scheme, gathering the field every step.
 
 This is the loop of a test-particle code: `gather` gives the electric field at
 all markers at once, from the compiled gather. The field is that of a 2D potential well,

tutorials/kernels.ipynb

@@ -5,7 +5,7 @@
    "id": "0",
    "metadata": {},
    "source": [
-    "# The kernels\n",
+    "# Kernels\n",
     "\n",
     "The compiled gather and scatter kernels behind `Field`: their versions, how one is chosen, and calling them directly.\n",
     "\n",