Usage - Revision history

Jrheinlaender: /* iMath Options */

2020-11-15T19:11:14Z

iMath Options

← Older revision		Revision as of 19:11, 15 November 2020
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	The behaviour of iMath can be changed by setting options. There are three ways of doing this		The behaviour of iMath can be changed by setting options. There are three ways of doing this
	# Globally for all documents from the Tools - Options - LibreOffice Writer - iMath global defaults dialog		# Globally for all documents from the Tools - Options - LibreOffice Writer - iMath global defaults dialog
	# Specifically for one document from the iMath - Settings		# Specifically for one document from the [[Document settings\|iMath - Settings]]
	# Specifically for one formula line with the keyword [[OPTIONS]]		# Specifically for one formula line with the keyword [[OPTIONS]]

Jrheinlaender at 16:27, 15 November 2020

2020-11-15T16:27:00Z

← Older revision		Revision as of 16:27, 15 November 2020
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	The best way to learn how to use iMath is to look at the iMath-tour.odt document corresponding to your version of iMath in this [http://sourceforge.net/projects/ooo-imath/files folder].		The best way to learn how to use iMath is to look at the iMath-tour.odt document corresponding to your version of iMath in this [http://sourceforge.net/projects/ooo-imath/files folder].

			Usage with Impress is very similar to usage with Writer. The main difference is that Math objects in an Impress document cannot be anchored in any specific order. Therefore, the recalculation order of the iMath formulas inside each Impress page is defined by the object names. The object names can be set in the context menu (Properties) or in the Navigator. The user is responsible to name the Math objects in such a way that calculation will happen in the desired order.

	== Some background on numerics ==		== Some background on numerics ==

Jrheinlaender: /* iMath Options */

2017-07-20T19:21:17Z

iMath Options

← Older revision		Revision as of 19:21, 20 July 2017
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	The behaviour of iMath can be changed by setting options. There are three ways of doing this		The behaviour of iMath can be changed by setting options. There are three ways of doing this
	# Globally for all documents from the ~~Extras~~ - Options - LibreOffice Writer - iMath global defaults dialog		# Globally for all documents from the Tools - Options - LibreOffice Writer - iMath global defaults dialog
	# Specifically for one document from the iMath - Settings		# Specifically for one document from the iMath - Settings
	# Specifically for one formula line with the keyword [[OPTIONS]]		# Specifically for one formula line with the keyword [[OPTIONS]]

Jrheinlaender at 19:36, 17 July 2017

2017-07-17T19:36:29Z

@@ Line 35: / Line 35: @@
 The behaviour of iMath can be changed by setting options. There are three ways of doing this
-# Globally for all documents
+# Globally for all documents from the Extras - Options - LibreOffice Writer - iMath global defaults dialog
-# Specifically for one document
+# Specifically for one document from the iMath - Settings
-# Specifically for one formula line
+# Specifically for one formula line with the keyword [[OPTIONS]]

Jrheinlaender: /* Some pitfalls */

2014-10-14T18:29:57Z

Some pitfalls

← Older revision		Revision as of 18:29, 14 October 2014
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	The expression %e^(-710) creates a floating point overflow error (not underflow as might be expected). This is because CLN calculates it as 1 / %e^710.		The expression %e^(-710) creates a floating point overflow error (not underflow as might be expected). This is because CLN calculates it as 1 / %e^710.

	There is a difference between VAL(%e)^{-10^18} and VAL(%e^{-10^18}). In the first case, the exponent ~~gets~~ converted to a float before doing the exponentiation, because the basis is already a float. In the second case, the exponent is an integer and stays integer - but only 32-bit integer exponents are allowed. So you get an error. You can write VAL(%e^{-10^18.0}) instead.		There is a difference between VAL(%e)^{-10^18} and VAL(%e^{-10^18}). In the first case, the exponent is converted to a float before doing the exponentiation, because the basis is already a float. In the second case, the exponent is an integer and stays integer - but only 32-bit integer exponents are allowed. So you get an error. You can write VAL(%e^{-10^18.0}) instead.

	== iMath Options ==		== iMath Options ==

Jrheinlaender: /* Automatic evaluation of expressions */

2014-10-14T18:27:51Z

Automatic evaluation of expressions

← Older revision		Revision as of 18:27, 14 October 2014
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	GiNaC does some automatic simplifications whenever you create an expression. Here are some examples:		GiNaC does some automatic simplifications whenever you create an expression. Here are some examples:
	1/15 + 3/8 -> 53/120		1/15 + 3/8 -> 53/120
	2^{-10^3} -> 1/1071508607186267320948...		2^{-10^3} -> 1/1071508607186267320948...
	a + a -> 2 a		a + a -> 2 a
	You can see these simplifications if you turn on auto-formatting. Only simplifications that are mathematically safe are performed. For details, consult the [http://www.ginac.de/tutorial/Automatic-evaluation.html#Automatic-evaluation GiNaC documentation].		You can see these simplifications if you turn on auto-formatting. Only simplifications that are mathematically safe are performed. For details, consult the [http://www.ginac.de/tutorial/Automatic-evaluation.html#Automatic-evaluation GiNaC documentation].

Jrheinlaender: /* Number types */

2014-10-14T18:27:26Z

Number types

← Older revision		Revision as of 18:27, 14 October 2014
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	To see the difference, enter these two expression (turn on auto-formatting):		To see the difference, enter these two expression (turn on auto-formatting):
	2.0^{-10^3}		2.0^{-10^3}
	2^{-10^3}		2^{-10^3}
	If you want to benchmark your CPU, you can increase the exponent of -10 ...		If you want to benchmark your CPU, you can increase the exponent of -10 ...

	When you use VAL() or ITERATE() everything is converted to floats.		When you use VAL() or ITERATE() everything is converted to floats.

	For further details, consult {http://www.ginac.de/tutorial/Numbers.html#Numbers GiNaC] and [http://www.ginac.de/CLN/cln.html#Ordinary-number-types CLN].		For further details, consult [http://www.ginac.de/tutorial/Numbers.html#Numbers GiNaC] and [http://www.ginac.de/CLN/cln.html#Ordinary-number-types CLN].

	=== Automatic evaluation of expressions ===		=== Automatic evaluation of expressions ===

Jrheinlaender: /* Number types */

2014-10-14T18:26:47Z

Number types

← Older revision		Revision as of 18:26, 14 October 2014
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	=== Number types ===		=== Number types ===

	There are two very different modes of numeric calculation available in iMath. As long as you use only integers and rational numbers, iMath (or rather, the underlying CLN library) will calculate exact results. As soon as you introduce floating point numbers (just writing 2.0 instead of 2 is enough), iMath will ~~swith~~ to approximate calculations with a precision of 17 digits (this is the default of the underlying GiNaC library). Not only the precision, but also the size of floating point numbers is limited. You can have an exponent of maximum 32 bits length.		There are two very different modes of numeric calculation available in iMath. As long as you use only integers and rational numbers, iMath (or rather, the underlying CLN library) will calculate exact results. As soon as you introduce floating point numbers (just writing 2.0 instead of 2 is enough), iMath will switch to approximate calculations with a precision of 17 digits (this is the default of the underlying GiNaC library). Not only the precision, but also the size of floating point numbers is limited. You can have an exponent of maximum 32 bits length.

	To see the difference, enter these two expression (turn on auto-formatting):		To see the difference, enter these two expression (turn on auto-formatting):

Jrheinlaender: /* How to use iMath */

2014-10-14T18:25:45Z

How to use iMath

← Older revision		Revision as of 18:25, 14 October 2014
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	The best way to learn how to use iMath is to look at the iMath-tour.odt document corresponding to your version of iMath in this [http://sourceforge.net/projects/ooo-imath/files folder].		The best way to learn how to use iMath is to look at the iMath-tour.odt document corresponding to your version of iMath in this [http://sourceforge.net/projects/ooo-imath/files folder].

			== Some background on numerics ==

			=== Number types ===

			There are two very different modes of numeric calculation available in iMath. As long as you use only integers and rational numbers, iMath (or rather, the underlying CLN library) will calculate exact results. As soon as you introduce floating point numbers (just writing 2.0 instead of 2 is enough), iMath will swith to approximate calculations with a precision of 17 digits (this is the default of the underlying GiNaC library). Not only the precision, but also the size of floating point numbers is limited. You can have an exponent of maximum 32 bits length.

			To see the difference, enter these two expression (turn on auto-formatting):
			2.0^{-10^3}
			2^{-10^3}
			If you want to benchmark your CPU, you can increase the exponent of -10 ...

			When you use VAL() or ITERATE() everything is converted to floats.

			For further details, consult {http://www.ginac.de/tutorial/Numbers.html#Numbers GiNaC] and [http://www.ginac.de/CLN/cln.html#Ordinary-number-types CLN].

			=== Automatic evaluation of expressions ===

			GiNaC does some automatic simplifications whenever you create an expression. Here are some examples:
			1/15 + 3/8 -> 53/120
			2^{-10^3} -> 1/1071508607186267320948...
			a + a -> 2 a
			You can see these simplifications if you turn on auto-formatting. Only simplifications that are mathematically safe are performed. For details, consult the [http://www.ginac.de/tutorial/Automatic-evaluation.html#Automatic-evaluation GiNaC documentation].

			=== Some pitfalls ===

			The expression %e^(-710) creates a floating point overflow error (not underflow as might be expected). This is because CLN calculates it as 1 / %e^710.

			There is a difference between VAL(%e)^{-10^18} and VAL(%e^{-10^18}). In the first case, the exponent gets converted to a float before doing the exponentiation, because the basis is already a float. In the second case, the exponent is an integer and stays integer - but only 32-bit integer exponents are allowed. So you get an error. You can write VAL(%e^{-10^18.0}) instead.

	== iMath Options ==		== iMath Options ==

Jrheinlaender: /* Available options */

2014-10-14T18:03:31Z

Available options

← Older revision		Revision as of 18:03, 14 October 2014
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	The formula-specific options can be accessed through the context menu (this is the preferred way) or by editing the formula text (see [[Reference#Options]] for details). All options listed in the sections for global and document-specific formatting can be set here.		The formula-specific options can be accessed through the context menu (this is the preferred way) or by editing the formula text (see [[Reference#Options]] for details). All options listed in the sections for global and document-specific formatting can be set here.

	~~=== Available options ===~~