Programmer Guide/Command Reference/EVAL/dct - Revision history

Christian at 18:24, 21 April 2011

2011-04-21T18:24:31Z

← Older revision		Revision as of 20:24, 21 April 2011
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	:;<var>dir</var>:the direction of the dct (default=0)		:;<var>dir</var>:the direction of the dct (default=0)
	:::{\|class="keinrahmen"		:::{\|class="keinrahmen"
	\|''dir''='''0''' \|\|-> forward dct		\|''dir''='''0''' \|\|→ forward dct
	\|-		\|-
	\|otherwise \|\|-> inverse (or backward) dct		\|otherwise \|\|→ inverse (or backward) dct
	\|}		\|}
	;Result: A vector ''y'' containing the result of the transformation. In the following table NX is equal to <code>nrow(''x'')</code>.		;Result: A vector ''y'' containing the result of the transformation. In the following table NX is equal to <code>nrow(''x'')</code>.
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	\|'''0'''		\|'''0'''
	\|data samples		\|data samples
	\|<code>0<''n''<=NX</code>		\|<code>0<''n''≤NX</code>
	\|NX		\|NX
	\|dct coefficients		\|dct coefficients
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	\|'''1'''		\|'''1'''
	\|dct coefficients		\|dct coefficients
	\|<code>0<''n''<=NX</code>		\|<code>0<''n''≤NX</code>
	\|NX		\|NX
	\|data samples		\|data samples

193.171.195.48 at 09:31, 21 April 2011

2011-04-21T09:31:17Z

← Older revision		Revision as of 11:31, 21 April 2011
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	\|inverse dct; the vector ''x'' is expanded with zeros to length ''n'' and the inverse transform is applied to the expanded vector (smoothing or liftering)		\|inverse dct; the vector ''x'' is expanded with zeros to length ''n'' and the inverse transform is applied to the expanded vector (smoothing or liftering)
	\|}		\|}
	;See also: [[~~Programmer_Guide/Command_Reference/EVAL~~/fft\|fft]], [[~~Programmer_Guide/Command_Reference/EVAL~~/ifft\|ifft]], [[~~Programmer_Guide/Command_Reference/EVAL~~/dft\|dft]], [[~~Programmer_Guide/Command_Reference/EVAL~~/cepstrum\|cepstrum]], [[~~Programmer_Guide/Command_Reference/EVAL~~/lpc\|lpc~~]], [[Programmer_Guide/Command_Reference/EVAL/complex arithmetic\|complex arithmetic~~]]		;See also: [[../fft\|fft]], [[../ifft\|ifft]], [[../dft\|dft]], [[../cepstrum\|cepstrum]], [[../lpc\|lpc]]

	[[~~Programmer_Guide~~/~~Command_Reference/EVAL~~#Functions\|<function list>]]		[[../#Functions\|<function list>]]

Toni at 12:13, 12 April 2011

2011-04-12T12:13:38Z

← Older revision		Revision as of 14:13, 12 April 2011
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	\|data samples		\|data samples
	\|NX		\|NX
	\|inverse dct; if ''n''<NX only the first ''n'' coefficients of ''x'' are used (smoothing or liftering)		\|inverse dct; if ''n''<NX only the first ''n'' coefficients of ''x'' are used, all other are set to 0 (smoothing or liftering)
	\|-		\|-
	\|'''1'''		\|'''1'''

Toni at 12:12, 12 April 2011

2011-04-12T12:12:42Z

← Older revision		Revision as of 14:12, 12 April 2011
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	\|otherwise \|\|-> inverse (or backward) dct		\|otherwise \|\|-> inverse (or backward) dct
	\|}		\|}
	;Result: A vector ''y'' containing the result of the transformation. In the following table NX is equal to <code>nrow(''x'')</code>		;Result: A vector ''y'' containing the result of the transformation. In the following table NX is equal to <code>nrow(''x'')</code>.
	:{\|class="einrahmen"		:{\|class="einrahmen"
	!''dir'' !! ''x'' !! ''n'' !! dct-<BR>length !! ''y'' !! nrow(''y'') !! description		!''dir'' !! ''x'' !! ''n'' !! dct-<BR>length !! ''y'' !! nrow(''y'') !! description

Toni at 12:12, 12 April 2011

2011-04-12T12:12:23Z

← Older revision		Revision as of 14:12, 12 April 2011
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	Compute the forward or inverce '''discrete cosine transform''' (dct) of the input vector ''x''. This function was implemented for the computation of the MFCC (mel-cepstrum coefficients).		Compute the forward or inverce '''discrete cosine transform''' (dct) of the input vector ''x''. This function was implemented for the computation of the MFCC (mel-cepstrum coefficients).
	;Usage:<code>dct(<var>x</var> {, <var>n</var> {, <var>dir</var>)</code>		;Usage:<code>dct(<var>x</var> {, <var>n</var> {, <var>dir</var>)</code>
	:;<var>x</var>the data vector		:;<var>x</var>:the data or coefficient vector
	:;<var>n</var>:the number of dct coefficients to compute or to use (default=<code>nrow(''x'')</code>); the meaning of this argument depends on the value of ''dir''		:;<var>n</var>:the number of dct coefficients to compute or to use (default=<code>nrow(''x'')</code>); the meaning of this argument depends on the value of ''dir''
	:;<var>dir</var>:the direction of the dct (default=0)		:;<var>dir</var>:the direction of the dct (default=0)

Toni at 12:11, 12 April 2011

2011-04-12T12:11:58Z

← Older revision		Revision as of 14:11, 12 April 2011
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	{{DISPLAYTITLE:{{SUBPAGENAME}}}}		{{DISPLAYTITLE:{{SUBPAGENAME}}}}
	Compute the forward or inverce '''discrete cosine transform''' (dct) of the input vector ''x''. This function was implemented for the computation of the MFCC (mel-cepstrum coefficients)		Compute the forward or inverce '''discrete cosine transform''' (dct) of the input vector ''x''. This function was implemented for the computation of the MFCC (mel-cepstrum coefficients).
	;Usage:<code>dct(<var>x</var> {, <var>n</var> {, <var>dir</var>)</code>		;Usage:<code>dct(<var>x</var> {, <var>n</var> {, <var>dir</var>)</code>
	:;<var>x</var>the data vector		:;<var>x</var>the data vector

Toni at 12:11, 12 April 2011

2011-04-12T12:11:17Z

← Older revision		Revision as of 14:11, 12 April 2011
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	:;<var>n</var>:the number of dct coefficients to compute or to use (default=<code>nrow(''x'')</code>); the meaning of this argument depends on the value of ''dir''		:;<var>n</var>:the number of dct coefficients to compute or to use (default=<code>nrow(''x'')</code>); the meaning of this argument depends on the value of ''dir''
	:;<var>dir</var>:the direction of the dct (default=0)		:;<var>dir</var>:the direction of the dct (default=0)
	:::{class="keinrahmen"		:::{\|class="keinrahmen"
	\|''dir''='''0''' \|\|-> forward dct		\|''dir''='''0''' \|\|-> forward dct
	\|-		\|-

Toni at 12:10, 12 April 2011

2011-04-12T12:10:55Z

← Older revision		Revision as of 14:10, 12 April 2011
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	;Usage:<code>dct(<var>x</var> {, <var>n</var> {, <var>dir</var>)</code>		;Usage:<code>dct(<var>x</var> {, <var>n</var> {, <var>dir</var>)</code>
	:;<var>x</var>the data vector		:;<var>x</var>the data vector
	:;<var>n</var>:the number of dct coefficients to compute or to use (default=<code>nrow(''x'')); the meaning of this argument depends on the value of ''dir''		:;<var>n</var>:the number of dct coefficients to compute or to use (default=<code>nrow(''x'')</code>); the meaning of this argument depends on the value of ''dir''
	:;<var>dir</var>:the direction of the dct (default=0)		:;<var>dir</var>:the direction of the dct (default=0)
	:::{class="keinrahmen"		:::{class="keinrahmen"
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	\|-		\|-
	\|otherwise \|\|-> inverse (or backward) dct		\|otherwise \|\|-> inverse (or backward) dct
			\|}
	;Result: A vector ''y'' containing the result of the transformation. In the following table NX is equal to <code>nrow(''x'')</code>		;Result: A vector ''y'' containing the result of the transformation. In the following table NX is equal to <code>nrow(''x'')</code>
	:{\|class="einrahmen"		:{\|class="einrahmen"

Toni at 12:09, 12 April 2011

2011-04-12T12:09:59Z

← Older revision		Revision as of 14:09, 12 April 2011
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	;Result: A vector ''y'' containing the result of the transformation. In the following table NX is equal to <code>nrow(''x'')</code>		;Result: A vector ''y'' containing the result of the transformation. In the following table NX is equal to <code>nrow(''x'')</code>
	:{\|class="einrahmen"		:{\|class="einrahmen"
	!''dir'' !! ''n'' !! dct-<BR>length !! ''y'' !! nrow(''y'') !! description		!''dir'' !! ''x'' !! ''n'' !! dct-<BR>length !! ''y'' !! nrow(''y'') !! description
	\|-		\|-
	\|'''0'''		\|'''0'''
			\|data samples
	\|<code>0<''n''<=NX</code>		\|<code>0<''n''<=NX</code>
	\|NX		\|NX
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	\|-		\|-
	\|'''1'''		\|'''1'''
			\|dct coefficients
	\|<code>0<''n''<=NX</code>		\|<code>0<''n''<=NX</code>
	\|NX		\|NX
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	\|-		\|-
	\|'''1'''		\|'''1'''
			\|dct coefficients
	\|<code>''n''>NX</code>		\|<code>''n''>NX</code>
	\|''n''		\|''n''

Toni at 12:08, 12 April 2011

2011-04-12T12:08:45Z

← Older revision		Revision as of 14:08, 12 April 2011
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	\|-		\|-
	\|'''1'''		\|'''1'''
	\|<code>0<''n''<= NX</code>		\|<code>0<''n''<=NX</code>
	\|NX		\|NX
	\|data samples		\|data samples