Use gaussianprime (same as gaussiandot in this case) to align more clearly with analytical solution.

testing/models_basic/hertzian_dipole_fs_analytical/hertzian_dipole_fs_analytical.in

@@ -3,6 +3,6 @@
 #dx_dy_dz: 0.001 0.001 0.001
 #time_window: 3e-9
 
-#waveform: gaussiandot 1 1e9 myWave
+#waveform: gaussianprime 1 1e9 myWave
 #hertzian_dipole: z 0.050 0.050 0.050 myWave
 #rx: 0.070 0.070 0.070