Tips and tricks - Revision history

DeFeroci at 21:51, 25 February 2023

2023-02-25T21:51:53Z

← Older revision		Revision as of 21:51, 25 February 2023
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	=== Execute portions of code ===		=== Execute portions of code ===
	You can execute only a portion of code by highlighting it in the ''script editor'' window and running it with ''ctlr+r'' or the ''run'' button.		You can execute only a portion of code by highlighting it in the ''script editor'' window and running it with ''ctlr+r'' or the ''run'' button.


			=== Custom ''Highlighting style'' ===
			To use custom color highlighting in ''script window'' and '' console'' add the xml style file to <code>PATH/gtksourceview/</code>; where <code>PATH</code> is main Gretl directory. You can see it in ''Tools -> Preferences -> General''.

			After that, go to ''Tools -> Preferences -> Editor'' and select your file name in ''Highlighting style'' drop-down list.

	__FORCETOC__		__FORCETOC__

DeFeroci at 11:50, 24 February 2023

2023-02-24T11:50:32Z

← Older revision		Revision as of 11:50, 24 February 2023
Line 45:		Line 45:
	4		4
	</pre>		</pre>


			=== Backslash to split lines===
			In some cases a line of code could be very long. Take for example the declaration of a matrix:
			<pre>
			matrix M = {1,2,3;4,5,6;7,8,9;10;11;12;13,14,15;16,17,18}
			</pre>
			It is difficult to read rows and columns. You can use the symbol <code>\</code> to split the line and improve readability.
			<pre>
			matrix M = { \
			1,2,3; \
			4,5,6; \
			7,8,9; \
			10,11,12; \
			13,14,15; \
			16,17,18}
			</pre>


			=== Execute portions of code ===
			You can execute only a portion of code by highlighting it in the ''script editor'' window and running it with ''ctlr+r'' or the ''run'' button.
	__FORCETOC__		__FORCETOC__

DeFeroci at 00:17, 14 January 2023

2023-01-14T00:17:25Z

← Older revision		Revision as of 00:17, 14 January 2023
Line 45:		Line 45:
	4		4
	</pre>		</pre>
			__FORCETOC__

DeFeroci: Add "=" trick for eval

2023-01-14T00:16:40Z

Add "=" trick for eval

← Older revision		Revision as of 00:16, 14 January 2023
Line 27:		Line 27:
	</pre>		</pre>
	Now run the script (push the gears button or Ctrl+R). The successive estimates of x and y will be monitored. Other information can easily be monitored as well, the value of the criterion <code>-(1-x)^2 - 100 * (y - x^2)^2</code> for instance, by simply including it in the <code>printf</code> command in the Rosenbrook function.		Now run the script (push the gears button or Ctrl+R). The successive estimates of x and y will be monitored. Other information can easily be monitored as well, the value of the criterion <code>-(1-x)^2 - 100 * (y - x^2)^2</code> for instance, by simply including it in the <code>printf</code> command in the Rosenbrook function.


			=== "=" trick for eval ===
			Sometimes you simply need to check the result of an expression in the Gretl console, such as 2+2. To do this you should use the <code>eval</code> command like this:
			<pre>
			? eval 2+2
			4
			</pre>
			Since without the command, gretl raises an error:
			<pre>
			? 2+2
			Parse error at unexpected token '2'
			</pre>
			But <code>eval</code> is too long to type. You can use an <code>=</code> before the expression (as in a spreasheet) to get the same result as <code>eval</code>:
			<pre>
			? =2+2
			4
			</pre>

Ekkehart: Formatting improved

2023-01-11T07:55:31Z

Formatting improved

← Older revision		Revision as of 07:55, 11 January 2023
Line 19:		Line 19:

	# This invokes the maximization routine		# This invokes the maximization routine
	matrix theta = {0, 0} # initial values for theta		matrix theta = {0, 0} # initial values for theta
	set max_verbose off		set max_verbose off
	M = BFGSmax(&theta, Rosenbrock(theta) )		M = BFGSmax(&theta, Rosenbrock(theta) )
	printf " \r" # destroy the last step message		printf " \r" # destroy the last step message
	flush # flush it		flush # flush it
	printf "\ntheta: %8.4f \n", theta		printf "\ntheta: %8.4f \n", theta
	</pre>		</pre>
	Now run the script (push the gears button or Ctrl+R). The successive estimates of x and y will be monitored. Other information can easily be monitored as well, the value of the criterion <code>-(1-x)^2 - 100 * (y - x^2)^2</code> for instance, by simply including it in the <code>printf</code> command in the Rosenbrook function.		Now run the script (push the gears button or Ctrl+R). The successive estimates of x and y will be monitored. Other information can easily be monitored as well, the value of the criterion <code>-(1-x)^2 - 100 * (y - x^2)^2</code> for instance, by simply including it in the <code>printf</code> command in the Rosenbrook function.

Ekkehart: deleted left-over word

2023-01-11T07:51:27Z

deleted left-over word

← Older revision		Revision as of 07:51, 11 January 2023
Line 3:		Line 3:
	It is sometimes irritating when a calculation takes very long and nothing appears to happen. In such cases a step monitor may be useful to indicate the state of the calculations. It is a simple gimmick.		It is sometimes irritating when a calculation takes very long and nothing appears to happen. In such cases a step monitor may be useful to indicate the state of the calculations. It is a simple gimmick.

	Take, as an example, a modification of the Listing 37.1: Finding the minimum of the Rosenbrock function with the BFGSmax routine given in Gretl's user guide. The <code>printf</code>~~current~~ command prints the values of x and y and ends with a carriage return. The command <code>flush</code> induces printing at each step. To simulate a time consuming routine, a delay of .003 has been inserted by giving the command <code>sleep(.003)</code>.		Take, as an example, a modification of the Listing 37.1: Finding the minimum of the Rosenbrock function with the BFGSmax routine given in Gretl's user guide. The <code>printf</code> command prints the values of x and y and ends with a carriage return. The command <code>flush</code> induces printing at each step. To simulate a time consuming routine, a delay of .003 has been inserted by giving the command <code>sleep(.003)</code>.

	Open the the gretl script editor (File → Script files → New script) and paste the following code:		Open the the gretl script editor (File → Script files → New script) and paste the following code:

DeFeroci: fixed formatting

2023-01-04T01:56:31Z

fixed formatting

@@ Line 6: / Line 6: @@
 Open the the gretl script editor (File → Script files → New script) and paste the following code:
 # This invokes the maximization routine
-<code>set verbose off</code>
+matrix theta = {0, 0} # initial values for theta
 set max_verbose off
-<code># This defines the function to be maximized</code>
+M = BFGSmax(&theta, Rosenbrock(theta) )
 printf "                      \r"              # destroy the last step message
-<code>function scalar Rosenbrock( const matrix param "parameters" )</code>
+flush                                          # flush it
 printf "\ntheta: %8.4f \n", theta
-<code>scalar x = param[1]</code>
+</pre>
 Now run the script (push the gears button or Ctrl+R). The successive estimates of x and y will be monitored. Other information can easily be monitored as well, the value of the criterion <code>-(1-x)^2 - 100 * (y - x^2)^2</code> for instance, by simply including it in the <code>printf</code> command in the Rosenbrook function.

Ekkehart at 14:57, 30 December 2022

2022-12-30T14:57:53Z

← Older revision		Revision as of 14:57, 30 December 2022
Line 6:		Line 6:

	Open the the gretl script editor (File → Script files → New script) and paste the following code:		Open the the gretl script editor (File → Script files → New script) and paste the following code:


			<code>set verbose off</code>

	<code># This defines the function to be maximized</code>		<code># This defines the function to be maximized</code>
Line 30:		Line 33:

	<code>matrix theta = {0, 0} # initial values for theta</code>		<code>matrix theta = {0, 0} # initial values for theta</code>

	~~<code>set verbose off</code>~~

	<code>set max_verbose off</code>		<code>set max_verbose off</code>

Ekkehart at 14:54, 30 December 2022

2022-12-30T14:54:52Z

← Older revision		Revision as of 14:54, 30 December 2022
Line 1:		Line 1:

	=== Step monitor ===		=== Step monitor ===
	It is sometimes irritating when a calculation takes very long and nothing appears to happen. In such cases a step monitor may be useful to ~~indicates~~ the state of the calculations. It is a simple gimmick.		It is sometimes irritating when a calculation takes very long and nothing appears to happen. In such cases a step monitor may be useful to indicate the state of the calculations. It is a simple gimmick.

	Take, as an example, a modification of the Listing 37.1: Finding the minimum of the Rosenbrock function with the BFGSmax routine given in Gretl's user guide. The <code>printf</code>current command prints the values of x and y and ends with a carriage return. The command <code>flush</code> induces printing at each step. To simulate a time consuming routine, a delay of .003 has been inserted by giving the command <code>sleep(.003)</code>.		Take, as an example, a modification of the Listing 37.1: Finding the minimum of the Rosenbrock function with the BFGSmax routine given in Gretl's user guide. The <code>printf</code>current command prints the values of x and y and ends with a carriage return. The command <code>flush</code> induces printing at each step. To simulate a time consuming routine, a delay of .003 has been inserted by giving the command <code>sleep(.003)</code>.

Ekkehart at 14:54, 30 December 2022

2022-12-30T14:54:32Z

← Older revision		Revision as of 14:54, 30 December 2022
Line 1:		Line 1:

	=== Step monitor ===		=== Step monitor ===
	It is sometimes irritating when a calculation takes very long and nothing appears to happen. In such cases a step monitor may be useful ~~that~~ indicates the state of the calculations. It is a simple gimmick.		It is sometimes irritating when a calculation takes very long and nothing appears to happen. In such cases a step monitor may be useful to indicates the state of the calculations. It is a simple gimmick.

	Take, as an example, a modification of the Listing 37.1: Finding the minimum of the Rosenbrock function with the BFGSmax routine given in Gretl's user guide. The <code>printf</code> command prints the values of x and y and ends with a carriage return. The command <code>flush</code> induces printing at each step. To simulate a time consuming routine, a delay of .003 has been inserted by giving the command <code>sleep(.003)</code>.		Take, as an example, a modification of the Listing 37.1: Finding the minimum of the Rosenbrock function with the BFGSmax routine given in Gretl's user guide. The <code>printf</code>current command prints the values of x and y and ends with a carriage return. The command <code>flush</code> induces printing at each step. To simulate a time consuming routine, a delay of .003 has been inserted by giving the command <code>sleep(.003)</code>.

	Open the the gretl script editor (File → Script files → New script) and paste the following code:		Open the the gretl script editor (File → Script files → New script) and paste the following code: