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2018-04-06T04:47:15Z

Created page with "=⎕MF - Monitor Function= This function is available in both ''monadic'' and ''dyadic'' forms. =Monadic Function, Numeric Argument= {{BoxStart|<apll>Z←⎕MF R</apll> |Set..."

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=⎕MF - Monitor Function=
This function is available in both ''monadic'' and ''dyadic'' forms.

=Monadic Function, Numeric Argument=

{{BoxStart|<apll>Z←⎕MF R</apll>
|Sets or returns and sets a property of monitoring functions}}
{{BoxLine |<apll>R</apll>   is an integer singleton (<apll>¯2</apll>, <apll>¯1</apll>, <apll>1</apll>, <apll>2</apll>, or <apll>3</apll>)}}
{{BoxEnd |<apll>Z</apll>   is a numeric scalar specific to the value of <apll>R</apll>}}

<table border="1" cellpadding="5" cellspacing="0" rules="all" summary="">
<tr>
<td><apll> R</apll></td>
<td>Effect</td>
<td><apll>Z</apll></td>
</tr>
<tr valign="top">
<td><apll>¯2</apll></td>
<td>(None)</td>
<td>Returns the Timer Source currently in use<br />The default value is <apll>3</apll> (Performance Timer scaled to milliseconds — Scaled Performance)</td>
</tr>
<tr>
<td><apll>¯1</apll></td>
<td>(None)</td>
<td>Returns the current tick frequency in milliseconds</td>
</tr>
<tr>
<td><apll> 1</apll></td>
<td>Sets the new Timer Source to the Millisecond Timer</td>
<td>Returns the old timer source (<apll>1</apll>, <apll>2</apll>, or <apll>3</apll>)</td>
</tr>
<tr>
<td><apll> 2</apll></td>
<td>Sets the new Timer Source to the Performance Timer</td>
<td>Returns the old timer source (<apll>1</apll>, <apll>2</apll>, or <apll>3</apll>)</td>
</tr>
<tr>
<td><apll> 3</apll></td>
<td>Sets the new Timer Source to the Performance Timer scaled to milliseconds (Scaled Performance)</td>
<td>Returns the old timer source (<apll>1</apll>, <apll>2</apll>, or <apll>3</apll>)</td>
</tr>
</table>

There are three Timer Sources available for timing functions:

* <apll>1</apll>: Millisecond Timer, in units of a millisecond (Integers)
* <apll>2</apll>: Performance Timer dependent on the computer hardware and the Operating System (raw data) (Integers)
* <apll>3</apll>: Performance Timer dependent on the computer hardware and the Operating System, but scaled to units of milliseconds (Scaled Performance) (Floating Point numbers)

The expression <apll>⎕MF ¯2</apll> returns the current Timer Source (<apll>1</apll>, <apll>2</apll>, or <apll>3</apll>). Typically, you should use a Timer Source of <apll>3</apll> as it uses the highest precision Timer Frequency and returns its result in easily understood units of milliseconds. Under Windows, Timer Sources <apll>2</apll> and <apll>3</apll> both obtain their timing data from the function <b>QueryPerformanceCounter</b> which has a resolution of one microsecond or better.

The expression <apll>⎕MF ¯1</apll> returns the number of milliseconds per unit. For the Millisecond timer, this value is <apll>1.0</apll>. For the other two timers, it varies based on the computer hardware and the Operating System. Under Windows, it uses the function <b>QueryPerformanceFrequency</b> — to obtain the number of clock ticks per second, use <apll>1000÷⎕MF ¯1</apll>.

=Monadic Function, Character Argument=

{{BoxStart|<apll>Z←⎕MF R</apll>
|returns the Monitor Data for the function named in <apll>R</apll>}}
{{BoxLine |<apll>R</apll>   is a character scalar or vector}}
{{BoxEnd |<apll>Z</apll>   is a 3-column numeric vector of Monitor Data, one row per function line including the function header}}

The columns of the result as as follows:

* <apll>[1]</apll> time of execution on this line including subfunctions
* <apll>[2]</apll> always <apll>0</apll>
* <apll>[3]</apll> count of the number of times this line was executed

The first column of the result is a floating point number if the Timer Source is Scaled Performance (type <apll>3</apll>), integer otherwise.

The first row of the result applies to the function header where its first element is the sum of the Timer Values of all lines in the function.

=Dyadic Function=

{{BoxStart|<apll>L ⎕MF R</apll>
| Enables or disable Function Monitoring}}
{{BoxLine |<apll>L</apll>   is a Boolean singleton}}
{{BoxLine |<apll>R</apll>   is a character scalar or vector of zero or more function names.}}
{{BoxEnd |<apll>Z</apll>   is a Boolean vector one element per function named in <apll>R</apll> indicating the success (<apll>1</apll>) or failure (<apll>0</apll>) of the operation.}}

Function Monitoring is turned on (<apll>L=1</apll>) or off (<apll>L=0</apll>) for each of the functions named in <apll>R</apll>. For either value of <apll>L</apll>, all of the internal counters for each function are set to zero.

{{System Variables}}
{{Article footer}}

System Function MF - Revision history

WikiSysop: Created page with "=⎕MF - Monitor Function= This function is available in both ''monadic'' and ''dyadic'' forms. =Monadic Function, Numeric Argument= {{BoxStart|Z←⎕MF R |Set..."