Calculation mode
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.. rst-class:: no-caption-number

.. list-table:: **icntl**
   :header-rows: 0

   * - Value
     - Explanation
   * -  | (D=0)
     -  | Basic control option.
   * -  | =0
     -  | Normal PHITS calculation.
   * -  | =1
     -  | Output cross section and kerma factor (please see  /phits/sample/icntl1 in detail).
   * -  | =3
     -  | Output only input echo for checking memory usage, libraries, and file  links.
   * -  | =5
     -  | Calculation assuming all regions are void (no reaction, no ionization) for geometry  check, and volume and area calculations.
   * -  | =6
     -  | Source check. Source positions can be tallied by [t-product].
   * -  | =7
     -  | Execute [t-gshow] for graphical output.
   * -  | =8
     -  | Geometry output of xyz mesh tally with gshow option for graphical  output.
   * -  | =9
     -  | Execute [t-rshow] for graphical output.
   * -  | =10
     -  | Geometry output of reg mesh tally with rshow option for graphical  output.
   * -  | =11
     -  | Execute [t-3dshow] for graphical output.
   * -  | =12
     -  | Re-calculate using dumpall file. Dumpall file is specified  by file(15).
   * -  | =13
     -  | Use of function to sum up tally results (Sumtally function).
   * -  | =14
     -  | Use of automatic calculation of region volume.
   * -  | =15
     -  | Execute [t-wwbg] to obtain [ww bias] parameters.
   * -  | =16
     -  | Use of script of analysis function.
   * -  | =17
     -  | Execute [anatally] to obtain results of analysis function.

Cross sections and kerma factors used in the PHITS simulation can be  outputted by icntl=1.  Please see "/phits/sample/icntl1" in more details. 

By setting icntl=12, PHITS reads the previous event-by-event calculation  result from a dumpall file created when the dumpall=1  option was activated. All of the transport events are reproduced by the dumpall file without  being re-calculated again. Thus, maxcas and maxbch cannot be changed. This functionality is suitable for tallying different physics quantanties with  the same simulation setup, especially when such a simulation setup is  computational time consuming.   However, it should be noted that calculation with dumpall=1 may  create a huge dumpall file. Please refer to  :numref:`sec-dumpall`  for more details.

By setting icntl=13, two (or more) tally results can be summed: see :numref:`sumtally` for further detail.

By setting icntl=14 with **[t-volume]**, automatic calculations to obtain volumes of specified cells can be performed. See :numref:`[t-volume]` in more detail.

By setting icntl=15 with **[t-wwbg]**, automatic calculations to obtain parameters of **[ww bias]** can be performed. See :numref:`[t-wwbg]` for further detail.

When use of script of analysis function, icntl=16 should be set  in a PHITS input file.