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Monitor[expr,mon]

generates a temporary monitor cell in which the continually updated current value of mon is displayed during the course of evaluation of expr.

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Monitor

Monitor[expr,mon]

generates a temporary monitor cell in which the continually updated current value of mon is displayed during the course of evaluation of expr.

Details

  • Monitor[Table[e,{x,…}],x] generates a monitor cell that shows the continually updated current value of x during the evaluation of the Table.
  • In a notebook, the monitor cell normally appears directly after the cell in which Monitor[expr,mon] is evaluated. The cell is deleted as soon as the evaluation of expr is complete.
  • If Print, PrintTemporary, or similar output is generated before the evaluation of Monitor begins, it will appear before the monitor cell.
  • Any expression, including graphics and controls, can be given for mon.
  • Monitor[expr,mon,delay] will delay the indicated number of seconds before generating the monitor cell. If the evaluation of expr is complete before then, no monitor is displayed.

Examples

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Basic Examples  (3)

Monitor the value of n while the computation is running:

Display a progress indicator while the computation is running:

Monitor a fast process by using Pause to slow down:

Applications  (6)

Monitor NIntegrate, with steps along the axis and evaluation points on the axis:

Monitor NDSolve using an extrapolation method:

Monitor the actual steps taken by NDSolve solving the sine-Gordon PDE with a StepMonitor:

Monitor every attempted step taken by NDSolve time integrating of a wave equation with an EvaluationMonitor:

Steps in parameter space for a nonlinear fit:

Monitor the evolution of the model over the steps with a graph:

Implement a simple LU decomposition with a slowdown parameter :

Monitor an algorithm animation using MatrixForm or MatrixPlot:

Possible Issues  (2)

Monitor can increase the time of a calculation:

Use Refresh to control the update interval used for displaying:

If the computation being monitored completes during the initial delay, no monitor will be displayed:

Wolfram Research (2007), Monitor, Wolfram Language function, https://reference.wolfram.com/language/ref/Monitor.html.

Text

Wolfram Research (2007), Monitor, Wolfram Language function, https://reference.wolfram.com/language/ref/Monitor.html.

CMS

Wolfram Language. 2007. "Monitor." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/Monitor.html.

APA

Wolfram Language. (2007). Monitor. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Monitor.html

BibTeX

@misc{reference.wolfram_2025_monitor, author="Wolfram Research", title="{Monitor}", year="2007", howpublished="\url{https://reference.wolfram.com/language/ref/Monitor.html}", note=[Accessed: 01-December-2025]}

BibLaTeX

@online{reference.wolfram_2025_monitor, organization={Wolfram Research}, title={Monitor}, year={2007}, url={https://reference.wolfram.com/language/ref/Monitor.html}, note=[Accessed: 01-December-2025]}