cannot visualise gas/dust density across full/small dumps from phantom

[danieljprice]

for phantom simulations with multiple dust species, splash currently shows something like the following in the menu:

  1) x [au]                43) deltavz             
   2) y [au]                44) deltavx             
   3) z [au]                45) deltavy             
   4) particle mass [M_{Su  46) deltavz             
   5) h [au]                47) deltavx             
   6) density [g/cm^3]      48) deltavy             
   7) dustfrac1             49) deltavz             
   8) dustfrac2             50) deltavx             
   9) dustfrac3             51) deltavy             
  10) dustfrac4             52) deltavz             
  11) dustfrac5             53) deltavx             
  12) dustfrac6             54) deltavy             
  13) dustfrac7             55) deltavz             
  14) dustfrac8             56) deltavx             
  15) dustfrac9             57) deltavy             
  16) dustfrac10            58) deltavz             
  17) dustfrac11            59) deltavx [km/s]      
  18) tstop1                60) deltavy [km/s]      
  19) tstop2                61) deltavz [km/s]      
  20) tstop3                62) v_x [km/s]          
  21) tstop4                63) v_y [km/s]          
  22) tstop5                64) v_z [km/s]          
  23) tstop6                65) div v [1/s]         
  24) tstop7                66) dt [s]              
  25) tstop8                67) r                   
  26) tstop9                68) dustfrac            
  27) tstop10               69) log \rho_{g} [g/cm^3
  28) tstop11               70) \rho_{d} [g/cm^3]   
  29) deltavx               71) \rho_{d,1.37\gmm} [g
  30) deltavy               72) \rho_{d,2.57\gmm} [g
  31) deltavz               73) \rho_{d,4.81\gmm} [g
  32) deltavx               74) \rho_{d,9.01\gmm} [g
  33) deltavy               75) \rho_{d,16.9\gmm} [g
  34) deltavz               76) \rho_{d,31.6\gmm} [g
  35) deltavx               77) \rho_{d,59.3\gmm} [g
  36) deltavy               78) \rho_{d,111\gmm} [g/
  37) deltavz               79) \rho_{d,208\gmm} [g/
  38) deltavx               80) \rho_{d,390\gmm} [g/
  39) deltavy               81) \rho_{d,731\gmm} [g/
  40) deltavz               82) dust-to-gas ratio   
  41) deltavx               83) |v|                 
  42) deltavy             

the problem is that one cannot visualise rho_gas across full/small dumps because they appear in different columns.

Suggested changes here are to:

• replace the dustfrac columns with the dust/gas densities during the phantom data read, i.e. hide the fact that dustfrac ever existed, and simply provide rho, rho_g and rho_d and the densities for the various species as columns.
• similarly with deltavx, just reconstruct the velocity for each species during the phantom read and provide this as the columns instead of deltav
• a third possibility is to eliminate the different species from the menu entirely and prompt just for density and velocity, but with a prompt selecting the species. However I think this would be more confusing.