print command

Syntax:

print string keyword value

• string = text string to print, which may contain variables

• zero or more keyword/value pairs may be appended

• keyword = file or append or screen

*file* value = filename
*append* value = filename
*screen* value = *yes* or *no*

Examples:

print "Done with equilibration"
print 'Done with equilibration'
print "Done with equilibration" file info.dat

compute myTemp temp
variable t equal c_myTemp
print "The system temperature is now $t"

Description:

Print a text string to the screen and logfile. One line of output is generated. The text string must be a single argument, so it should be enclosed in quotes if it is more than one word. If it contains variables, they will be evaluated and their current values printed.

If the file or append keyword is used, a filename is specified to which the output will be written. If file is used, then the filename is overwritten if it already exists. If append is used, then the filename is appended to if it already exists, or created if it does not exist.

If the screen keyword is used, output to the screen and logfile can be turned on or off as desired.

If you want the print command to be executed multiple times (e.g. with changing variable values), there are 3 options. First, consider using the fix print command, which will print a string periodically during a simulation. Second, the print command can be used as an argument to the every option of the run command. Third, the print command could appear in a section of the input script that is looped over (see the jump and next commands).

See the variable command for a description of equal style variables which are typically the most useful ones to use with the print command. Equal-style variables can calculate formulas involving mathematical operations, global values calculated by a compute or fix, or references to other variables.

Restrictions:

none

Related commands:

fix print, variable

Default:

The option defaults are no file output and screen = yes.