problem.setcbmessage
problem.setcbmessage |
Purpose
Set a user callback to be called whenever Xpress Nonlinear outputs a line of text
Synopsis
problem.setcbmessage(callback, object)
callback(my_prob, my_object, msg, msgtype)
Arguments
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callback
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The function to be called whenever Xpress Nonlinear outputs a line of text.
callback does not return a value.
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my_prob
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The problem passed to the callback function.
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my_object
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The user-defined object passed as
object to
setcbmessage.
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msg
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String to be output.
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msgtype
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Type of message. The following are system-defined:
A negative value indicates that the Optimizer is about to finish and any buffers should be flushed at this time. User-defined values are also possible for msgtype. |
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object
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Address of a user-defined object, which can be used for any purpose by the function.
object is passed to
callback as
my_object.
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Example
The following example creates a log file into which all messages are placed. System messages are also printed on standard output:
log = '' p.setcbmessage(CBMessage, log)
A suitable callback function could resemble the following:
def CBMessage(Obj, msg, msgtype):
if msgtype < 0:
print(log)
log = ''
return
if msgtype >= 1 and msgtype <= 4:
print(msg)
else:
log += msg + ';'
Further information
If a user message callback is defined, screen output is automatically disabled.
Output can be directed into a log file by using problem.setlogfile.
Also, because of Python's garbage collection functions, it is advised to explicitly delete a problem at the end of its use (with the del command) if a message callback was set for that problem using setcbmessage.
def CBMessage(Obj, msg, msgtype): pass p = xp.problem() p.setcbmessage(CBMessage, None) [...] del p
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