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Mark Output

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QXL Monte Carlo New > Design > Mark Output

Marks one worksheet cell as an output of the Monte Carlo model. An output is a result: on every trial of a simulation, Quantum XL reads the value the cell has computed and collects it, so the report can describe how that result is distributed.

A marking is what tells Quantum XL that one worksheet cell takes part in the model. Marking a cell does not change the value in it and does not add a formula to it. It records, alongside the worksheet, that this cell is an input the simulation will write trial values into, or an output the simulation will read a result from.

Everything the model knows about a cell comes from its marking. A workbook with no markings has no model in it, however many formulas it holds.

What a cell has to be

An output must be a formula cell, because an output has to compute from the model.

Outputs can only be defined on cells that are formulas. The cell Sheet1!$B$5 does not contain a formula.

The cell is checked when the dialog opens and again when you press OK, because Excel stays live in between and the formula can be deleted while the dialog is open. The second refusal says so:

The cell changed in Excel while this dialog was open.

Nothing has been written when a commit is refused.

Merged cells cannot be marked. A protected sheet refuses a marking only when the write would actually fail, either because the cell is locked or because the sheet blocks the note every marking writes.

One cell at a time

Mark Output marks the single active cell. This is the one real structural difference from Mark Input, which marks a whole selected range. Because there is only ever one cell, there is no per-cell offset for a reference mode to describe, so the Relative and Absolute selector never appears in this dialog.

There is no Previous and Next pair either. Mark one cell, press OK, select the next cell and mark it.

The dialog

One page, no tabs, three sections:

Name. What this output is called in reports.

Statistics. Whether results are collected for this output at all.

Specification limits. The optional lower and upper limits the result is judged against.

Every control is described on the Options page.

What is written

Markings are stored in the workbook, so they travel with the file and survive being closed and reopened. Three things are written for each marked cell:

What	Where	What it is for
An Input or Output entry	in a hidden container sheet in the workbook	the marking itself: the name, the distribution or the spec limits, and every parameter
A defined name beginning DFSSXLTag_	in the workbook's defined names	how the entry finds its cell again after rows are inserted, cells are dragged, or a sheet is renamed
A note on the cell	on the cell itself	the indicator you can see, so a marked cell is visible on the worksheet

The container is the same format Quantum XL v17 wrote, so a workbook marked in v17 opens here.

Two pieces of information are v18 additions that v17 does not write and ignores when it meets them: each link also stores the cell address it currently points at, rewritten every time the marking is saved, and each link stores the name to display for it. The address is a fallback used when the defined name no longer resolves, so a link still finds its cell if the name is deleted. The value itself is always read from the cell at the moment of the run, never from that stored copy.

The display name is stored as an attribute rather than as the entry's text, so cleaning up a marking never deletes a named range of yours.

The note on the cell

The note on a marked cell is what makes the marking visible on the worksheet, and it summarises what was marked. An input note names the input, its distribution, one line per parameter, and whether the input can be optimized:

Quantum XL Input
Inlet pressure
Distribution=Normal
Mean=12.5
Standard deviation=0.4
Can be optimized=True

An output note names the output and the specification limits, and a limit that was not given has no line at all:

Quantum XL Output
Yield
LSL=98
USL=102

An unnamed cell shows (cell address) on its name line rather than a resolved address, so the note does not go stale when the cell moves. A value that came from a link shows (linked value) rather than a number, because the number is only known at run time.

What the marking carries that this dialog does not set

An output marking also records how the Optimizer scores this output against its specification limits, as either dpm (Normal Data) or Count Out of Spec (Non-Normal Data). That choice is not made here: it is made in the Optimizer's own setup, and it is stored on the output so it is remembered with the rest of the marking.

Removing a marking

Unmark removes the marking from the selected cells and leaves their formulas alone.